quality control at bosch vietnam by applying contamination management cycle in system cip project

MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION FACULTY FOR HIGH QUALITY TRAINING CAPSTONE PROJECT INDUSTRIAL MANAGEMENTQUALITY CONTROL AT BOS

Rationale

The management of contamination in the production process is crucial for organizations striving to increase the quality of their products By effectively addressing and mitigating contamination risks, companies can uphold customer value, drive innovation, and enhance overall product quality This rationale is supported by the following factors:

Customer Value and Innovation: In today's competitive market, customer satisfaction and loyalty are paramount Customers expect products that meet high- quality standards and are free from any contaminants that could compromise their performance expectations By proactively managing contamination in the production process, organizations can consistently deliver products that are free from contaminants, ensuring they meet customers' stringent quality requirements., thereby enhancing customer value Additionally, effective contamination management fosters innovation by encouraging the exploration of new technologies, best practices, and continuous improvement in production processes.

By focusing on minimizing the risk related to product quality, the project contributes to the organization's objectives of customer satisfaction and operational excellence It aligns with the company's vision by emphasizing the importance of delivering high-quality products and fostering innovation Additionally, the project addresses the incident-related claim, prompting proactive measures to prevent future occurrences and safeguard the company's reputation Through effective contamination management, the project significantly reduces the risk associated with compromised product quality, supporting the organization's commitment to excellence and customer value.

In conclusion, the author has chosen to delve into "Executing S-CIP project by applying contamination management cycle at BOSCH Vietnam" due to its crucial role in maintaining product quality and customer satisfaction This topic offers valuable insights into effective project execution strategies specifically tailored to contamination management By focusing on this aspect, the author aims to contribute to organizational success in minimizing contamination risks, ensuring superior product quality, and reinforcing customer trusts of market share

Aim of the study

Applying contamination management cycle at MSEx in Bosch Vietnam Co., Ltd. and reduce to zero contamination defect case case related to source of AOIs, Facet room, Mixing-Washing-Supermarket per month.

• Create a contamination library of known and unknown contamination source.

• Define process flow and reaction plan.

• Eliminate main contamination source by using problem solving toolbox.

• Validation and control methods for solutions.

Scope and object

Space scope: HcP, Mixing process & Washing process & Supermarket line 7.

Applying contamination cycle at Mixing process, Washing process and supermarket

Research methodology

The study utilized both qualitative and quantitative research approaches:

Qualitative research methods were employed to collect information regarding the challenges affecting contamination in the MSE1 department The author used focus group interviews to gain insights into issues and potential solutions from operators, engineers, and production experts The insights gathered from these interviews helped the author comprehend the existing contamination situation along the production line and gather recommendations for implementing solutions to eradicate the contamination source.

Quantitative research methods were used to acquire data samples outlining the prerequisites for implementing CMC in production The author employed statistical techniques to analyze the collected data, enabling the identification of predominant contaminations based on their materials and locations before proposing potential solutions.

Structure of the report

The structure of the thesis includes three main chapters and a conclusion section.

Chapter 1: Introduction to Bosch Vietnam Co., Ltd

Chapter 2: Contamination Management Cycle definition and contamination status at MSE1

Chapter 3: Solutions and control for contamination and evaluation

INTRODUCTION TO BOSCH VIETNAM., LTD

Bosch Group

Bosch Group, a global powerhouse in engineering and technology, has established itself as a prominent leader in various industries worldwide With a history spanning over a century, the company epitomizes innovation, precision, and reliability. Throughout its existence, Bosch has consistently pushed boundaries, reshaping industries, and transforming lives through groundbreaking advancements.

Founded by Robert Bosch in Stuttgart, Germany in 1886, Bosch Group commenced its journey as a small workshop for precision mechanics and electrical engineering Over time, the company gradually expanded its expertise and product range, evolving into a diversified corporation with a strong presence in automotive technology, industrial technology, consumer goods, and energy and building technology.

Today, Bosch Group boasts a global footprint, operating in over 60 countries and employing hundreds of thousands of dedicated professionals Its commitment to excellence is reflected in its diverse portfolio of products and services that cater to the needs of individuals, businesses, and society as a whole From automotive components like fuel injection systems and sensors to power tools, household appliances, and cutting-edge industrial solutions, Bosch's offerings span across diverse domains.

One of the key factors that sets Bosch Group apart is its unwavering focus on quality The company's dedication to precision and craftsmanship has earned it an unparalleled reputation for reliability and durability This commitment is deeply ingrained in Bosch's culture, influencing every aspect of their operations, from research and development to manufacturing and customer service.

Furthermore, Bosch Group recognizes the importance of sustainability and corporate social responsibility Environmental protection, resource efficiency, and ethical business practices are integral to its approach The company actively pursues initiatives to reduce carbon emissions, optimize energy usage, and promote sustainable manufacturing processes Bosch's commitment to sustainability extends beyond its own operations, as it collaborates with partners, customers, and stakeholders to drive positive change in society and the environment.

Bosch's success is underpinned by its relentless pursuit of innovation The company invests significantly in research and development, striving to anticipate and address evolving market needs By embracing emerging technologies, such as artificial intelligence, Internet of Things (IoT), and connected solutions, Bosch remains at the forefront of digital transformation, driving advancements across industries.

Bosch Vietnam

1.2.1 The process of formation and development

Figure 1.1: Factual information and statistics about Bosch in Vietnam in 2021

Bosch Vietnam has embarked on a transformative journey of formation and growth, defining itself as a pioneering force in the Vietnamese market Since its establishment in 1994, Bosch Vietnam has evolved from a humble representative office into a flourishing full subsidiary, making substantial contributions to Vietnam's economic landscape.

Source: Company websiteFigure 1.2: Bosch Vietnam’s logo

From the very beginning, Bosch Vietnam recognized the immense potential of the Vietnamese market and seized the opportunity to expand its operations Through strategic investments and unwavering commitment, the company has diversified its business divisions, creating a diverse portfolio that spans automotive technology, consumer goods, industrial technology, energy and building technology, and healthcare.

One of the key drivers behind Bosch Vietnam's success lies in its state-of-the-art manufacturing facilities Spread across different regions of Vietnam, these cutting- edge facilities not only cater to local demands but also serve as critical production hubs for global distribution By adhering to rigorous quality standards and leveraging advanced technologies, Bosch Vietnam ensures the delivery of exceptional products that meet the ever-evolving needs of customers.

However, Bosch Vietnam's impact extends far beyond its manufacturing prowess. The company is deeply committed to fueling innovation through robust research and development initiatives Collaborating closely with local partners, universities, and research institutions, Bosch Vietnam pioneers groundbreaking solutions tailored specifically to address the unique challenges faced by Vietnam By harnessing the collective expertise and knowledge of these collaborations, the company remains at the forefront of technological advancements, paving the way for a sustainable and prosperous future.

In addition to driving innovation, Bosch Vietnam is keenly aware of its corporate social responsibility With a strong focus on education, skills training, environmental stewardship, and community engagement, the company actively contributes to the betterment of Vietnamese society By empowering individuals and supporting local initiatives, Bosch Vietnam strives to build a brighter future for generations to come.

As Bosch Vietnam continues to forge ahead, it stands tall as an emblem of excellence, ingenuity, and unwavering dedication The company's formation and development underscore its commitment to Vietnam's progress, fostering economic growth, technological advancement, and social welfare With a blend of global expertise and local insight, Bosch Vietnam remains poised to shape the nation's future and leave an indelible mark on Vietnam's thriving industries.

The Head of Commercial (HcP/PC) and Head of Technical (HcP/PT) at HcP hold the responsibility for making decisions, setting objectives, and providing the overall direction for the company.

HcP/HSE (Health, Safety and Environment Department): oversees industrial safety and provides safety instructions to workers prior to their entry into the manufacturing lines.

HcP/MSE1: (Production Department): responsible for producing element.

HcP/MSE2: (Production Department): responsible for producing loopset.

HcP/MSE3: (Production Department): responsible for assembling to make pushbelt.

HcP/TEF: (Technical Department): maintains machinery, performs repairs when issues arise, manages documentation systems, oversees factory digitalization, and conducts research and development for product enhancement.

C/AUP: accountable for planning production volume and turnover.

Figure 1.3: Organizational Chart at Hcp

PS/QMM (Quality Management and Methodology Department): sustains customer satisfaction through internal evaluations and IATF certification, while ensuring product quality through training in techniques such as SPC and FMEA.

HcP/FCM (Facilities Management Department) supervises the upkeep of facilities and equipment to fulfill the requirements of the workforce.

PS CT/ETC (Engineering Technology Center): provides assistance for existing products within Bosch Vietnam and Bosch's global transmission technology division, responsible for formulating testing strategies, executing them, and assessing the results.

HcP/ICO (Information Coordination and Organization Department): handles information security-related issues and facilitates the installation of software on the company's system.

HcP/TGA (The Technical Training Center); provides technical training courses to cultivate young, dynamic, and innovative internal talents.

HcP/COM: responsible for commercial activities.

HcP/LOG (Logistics Management Department): manages inventory levels, monitors the quantity of raw materials utilized for input and output, and tracks the quantity of items shipped to customers per order.

HcP/CTG (Control Room): supervises the financial aspects and budget of the organization.

HcP/HRL (Human Resources Department): responsible for recruitment, training, compensation, and benefits.

HcP/CMR (Security Department): supervises overall security within the factory,provides protocols and registration documentation for external partners visiting the facility for filming or photography purposes, and assists with relevant documentation.

1.2.3 Organizational Chart of MSE1 department

The element production department includes:

MFO1(Operations): Supervisors and shift leader takes charge of the daily production of components, meeting component demand, upholding production standards, managing workforce allocation, and executing production enhancements.

MSE1.2 (Line Engineering): Assumes the role of optimizing line performance, devising production plans, leading quality issue resolution efforts, overseeing line and product releases, and driving improvement initiatives (such as BPS and addressing bottleneck processes) in manufacturing.

MSE1.1 (Process Engineering): Is responsible for process improvement, quality improvement, troubleshooting, documentation, performing inspections and product releases, and BPS activities in manufacturing Including: o MFE1.11: Fine blanking o MFE1.12: Hardening, deburring, mixing & end of line washing.

Figure 1.4: Organizational Chart at MSE1 Department

Product and consumer market at Bosch Vietnam

Pushbelt is a critical component of continuously variable transmissions (CVTs) that enables smooth and efficient power delivery As an integral part of the CVT system, the pushbelt acts as a vital link between the driving pulleys responsible for transmitting torque By utilizing advanced materials and engineering expertise, Bosch has created pushbelts that can effectively handle high torque loads while maintaining optimal performance.

One of the key advantages offered by Bosch's pushbelt technology is its ability to provide stepless gear ratio changes Unlike traditional automatic transmissions with fixed gear ratios, CVTs equipped with pushbelts allow for infinite variability within their operating range This results in improved fuel efficiency, smoother acceleration, and enhanced driving comfort.

Bosch's pushbelts are engineered with precision and durability in mind The belts are designed to withstand high temperatures, friction, and wear, ensuring long-lasting performance under challenging conditions Advanced manufacturing techniques and quality control measures ensure consistent and reliable operation, reducing maintenance requirements and enhancing overall vehicle reliability.

Furthermore, Bosch continuously invests in research and development to enhance its pushbelt technology Through extensive testing and analysis, the company explores new materials, designs, and manufacturing methods to further optimize performance and efficiency The pursuit of continuous improvement enables Bosch to stay at the forefront of pushbelt technology advancements, meeting the evolving demands of modern automotive applications.

The benefits of Bosch's pushbelt technology extend beyond passenger vehicles. This innovative solution finds application in a wide range of vehicles, including commercial vehicles, industrial machinery, and more The versatility and adaptability of Bosch's pushbelts make them suitable for various power transmission requirements across different industries.

Moreover, Bosch's commitment to sustainability is evident in its pushbelt technology By optimizing power transfer efficiency and reducing energy losses, CVTs with pushbelts contribute to lower fuel consumption and reduced emissions. This aligns with the company's vision of sustainable mobility and its dedication to creating environmentally friendly solutions.

In conclusion, Bosch's pushbelt technology has made significant strides in revolutionizing transmission systems, enabling smooth and efficient power transfer in modern vehicles With a focus on performance, durability, and sustainability, Bosch's pushbelts have become integral components in continuously variable transmissions. Through ongoing research and development efforts, Bosch continues to improve this technology, setting new benchmarks for efficiency, reliability, and driving comfort in the automotive industry.

MSE1 department produces element products.

MSE2 department manufactures loopset products.

MSE3 department performs error checking for elements and loopsets and assembles to create a complete pushbelt product.

Source: MSE1 department of Bosch Vietnam Co., Ltd

The Bosch Long Thanh factory in Dong Nai is the company's first belt manufacturing facility in Vietnam and specializes in manufacturing continuously variable transmission (CVT) belts The plant in Vietnam has been manufacturing CVT belts since 2008 In its initial production cycle, the factory produced 1.6 million goods. The manufacturer had distributed more than 25 million CVT belts as of March 2018. Three Bosch factories-one each in the Netherlands, Vietnam, and Mexico-produce CVT belts at the moment, with the Vietnam facility being the biggest and bringing in the most money.

There are several types of elements These elements vary in size and configuration, with a unique identification system denoting their specifications For instance, an element labeled as "24-9" signifies that it possesses a horizontal length of

24 millimeters and is equipped with nine loopsets that come together during assembly to make a good pushbelt.

With each element type, there are two kinds of element: normal element and filter element Filter element is like normal element but smaller and thinner, so it is used to be assembled into loopset to make a good pushbelt if the space is not enough for normal element.

These are element types: 24-9; 24-9AVO; 28-10; 30-10 and 30-12.

The full procedure of element includes: Fine-blanking  Hardening  DeburringBody-grindingMixingWashing.

Source: MSE1 department of Bosch Vietnam Co., Ltd

Toolshop: This is a cabin used for storing and maintaining molds for the fine- blanking process It's where molds are maintained after use, reshaped, and other components are worked on.

Decoiling: Raw materials arrive in the form of a coil Operators in charge of this step unwind the coil and feed it into the fine-blanking machine to create the product.

Fine-blanking: This process involves punching and cutting the coil to create the product using molds Depending on the product type, a suitable mold is used The process follows the sequence of clamping, forming, cutting, and unloading.

Hardening: This is a heat treatment process aimed at increasing the hardness of the element.

Figure 1.8: Flow and processes of element

Deburring: A grinding process that removes burrs, polishes the element, and cleans any dirt left from the fine-blanking process Edges of the element are also ground using stones, water, and chemicals.

Body grinding (only for specific products as required by Honda): This step involves grinding to remove burrs from the flank part of the element.

Storage and Mixing: After grinding, elements are stored and later used in the mixing process Mixing aims to achieve a perfect blend of elements since, after fine- blanking, no two elements are exactly alike.

Washing: All elements are washed and then moved to a supermarket area to await pickup requests from the assembly department.

Bosch Vietnam excels in a pull system, offering make-to-order products to Asian markets They serve notable industrial automobile customers like Hyundai, Honda, and Jatco The factory focuses on producing the exclusive CVT (Continuously Variable Transmission) Pushbelt, fulfilling orders from major clients such as Jatco, Honda, and Hyundai With over 5000 employees, they achieve an impressive daily production average of 1,700-2,000 belts per line, valued between $100 and $140 in the

Figure 1.9: Some of Bosch Vietnam’s customer market Bosch Vietnam is a leading player in the thriving Asian industrial automobile sector.

LITERATURE REVIEW

Quality and quality improvement

Quality has emerged as a pivotal factor influencing consumer choices when it comes to selecting from a range of competing products and services This trend is ubiquitous and applies whether the consumer is an individual, a corporate entity, a retail outlet, a banking or financial institution, or even a military defense program As such, comprehension and enhancement of quality are crucial elements that contribute to business prosperity, expansion, and heightened competitiveness There is a significant return on investment that can be derived from enhanced quality and the successful integration of quality as a fundamental component of the overall business strategy In this section, the author will provide practical definitions of quality and quality improvement The author will initiate the discussion with a brief overview of the various dimensions of quality and some fundamental terminology.

According to Garvin (1987), quality is defined in eight dimension or components:

Performance: Customers typically evaluate a product based on its ability to perform specific functions and the efficiency with which it does so For instance, one might assess PC spreadsheet software packages based on the data manipulation operations they can perform and their execution speed.

Reliability: This pertains to the frequency of product failure Complex products like appliances, automobiles, or airplanes are likely to require some repair over their lifespan If a product requires frequent repairs, it is deemed unreliable The reliability dimension significantly impacts customer perception of quality in many industries.

Durability: This refers to the effective service life of the product Customers naturally prefer products that function satisfactorily over an extended period This dimension is particularly important in industries like automobile and major appliances.

Serviceability:This dimension considers how easily a product can be repaired.

In many industries, customer perception of quality is directly influenced by the speed and cost-effectiveness of repairs or routine maintenance.

Aesthetics: This relates to the visual appeal of the product, often considering factors like style, color, shape, packaging options, tactile characteristics, and other sensory features.

Features: Customers often associate high-quality products with added features

- those that go beyond the basic performance offered by competitors.

Perceived Quality: In many cases, customers rely on a company’s past reputation regarding the quality of its products This reputation is influenced by highly visible product failures or recalls and by how customers are treated when they report a quality-related issue.

Conformance to Standards: A high-quality product is often seen as one that precisely meets the requirements placed on it For example, how well does a car hood fit? Is it perfectly flush with the fender height, and is the gap exactly the same on all sides? Parts that do not precisely meet the designer’s requirements can cause significant quality issues when used as components of a more complex assembly.

“Quality mean fitness for use”, this definition was defined by Dr Juran is a traditional one in quality fields Quality can be viewed from two perspectives: quality design and quality conformance Quality design refers to the intentional variations in product features that cater to different customer needs For instance, consider a service like law enforcement by government agencies The quality design is reflected in the relevant acts and rules, whereas the quality conformance depends upon how well these acts and rules are complied with by the enforcement agencies.

On the other hand, quality conformance is concerned with how well a product aligns with the design specifications Factors influencing quality conformance include the selection of manufacturing processes, workforce training and supervision, process controls, tests and inspection activities employed, adherence to these procedures, and workforce motivation to achieve quality.

However, there has been a tendency to associate quality more with conformance than with design This could be attributed to the limited formal education most designers and engineers receive in quality engineering methodology Consequently,there is often an overemphasis on a "conformance-to-specifications" approach to quality, regardless of whether the product meets the customer's needs when produced to standards This mindset also perpetuates the misconception that quality issues can be addressed solely in manufacturing or that improving quality necessitates "gold- plating" the product.

Moreover, there is a modern definition of quality “Quality is inversely proportional to variability”, and this definition only suggests that as the variability in the significant attributes of a product diminishes, the product’s quality improves.

Source: Douglas C Montgomery (2008) Figure 2.1: Warranty claims and repair cost of two companies

Figure 2.2: Distribution of quality characteristics of two companies

For example, in the past an American automobile company conducted a comparative study between a transmission manufactured domestically and one produced by a Japanese supplier The study was prompted by a significant difference in warranty claims and repair costs, with the Japanese-made transmission proving to be much more cost-effective (as shown in Figure 2.1).

The company randomly selected transmissions from each plant, disassembled them, and measured several key quality characteristics The results, generally represented in Figure 2.2, showed that while both distributions of critical dimensions were centered at the target value, the distribution for the US-manufactured transmissions occupied about 75% of the specification width This suggested that very few nonconforming units would be produced and that the plant was producing at a quality level deemed quite good within the company.

In contrast, the same critical characteristics for the Japanese-manufactured transmissions only occupied about 25% of the specification band This resulted in significantly less variability in the critical quality characteristics of the Japanese-built transmissions compared to those built in the US.

This finding is crucial As Jack Welch, former CEO of General Electric, noted, customers don't see the process's mean (the target in Figure 2.2), they only see the variability around that target that have not been removed This variability often has a significant impact on customers.

The reasons behind this difference are clear: reduced variability leads to lower costs and superior product quality (as Welch pointed out) The Japanese-built transmissions shifted gears more smoothly, ran more quietly, and were generally perceived by customers as superior to those built domestically Fewer repairs and warranty claims result in less rework and waste of time, effort, and money Thus, quality is indeed inversely proportional to variability and can be precisely communicated in a language everyone understands—money.

How did the Japanese achieve this? The answer lies in their systematic and effective use of the methods described in this book, leading us to define quality improvement.

Seven Quality Control Tools

A Check Sheet is a crucial instrument for efficient data gathering and examination It's a structured form designed to systematically accumulate necessary data.

Figure 2.4: Example of a check sheet

This tool is typically used to pinpoint the frequency and location of issues in a product or service Essentially, it's an empty form that methodically collects and organizes factual data right at the source.

The Check Sheet is tailored to the process under scrutiny It can record both variable and attribute data The data gathered can be either qualitative or quantitative. When the data is quantitative, it's often referred to as a tally sheet This collected data can then serve as input for other quality tools like histograms, bar graphs, and Pareto charts.

Research on check sheets has demonstrated their significant utility in data collection and analysis, particularly in areas such as quality management and production management Montgomery and Woodall’s study in 2008 highlighted the popularity of check sheets as a data collection method in quality control The study further revealed that check sheets simplify and enhance the efficiency of data collection and analysis compared to other techniques.

In another study conducted by Pham et al in 2019, check sheets were employed to gather data for assessing the appropriateness of production processes and suggesting enhancements This study underscored that check sheets are a straightforward and user-friendly tool for data collection and analysis in production processes.

In summary, a Check Sheet is a fundamental tool in data collection and analysis, particularly in the realms of quality and production management Its design allows for systematic and organized data collection directly from the source It accommodates both variable and attribute data, which can be either qualitative or quantitative The latter is often referred to as a tally sheet The data collected can subsequently be utilized in various quality tools such as histograms, bar graphs, and Pareto charts. Studies have underscored the efficiency, simplicity, and user-friendliness of check sheets in data collection and analysis, making them a popular choice in quality control and production processes.

The Pareto Principle, often referred to as the 80-20 rule, suggests that 80% of outcomes result from 20% of all causes This principle is a valuable tool in problem- solving as it helps prioritize the most significant contributors to a problem By focusing on these key areas, one can achieve substantial results with minimal effort. According to Prabir Jana & Manoj Tiwari (2021), The Pareto Principle, also known as the 80:20 rule, is attributed to its founder, Vilfredo Pareto This principle posits that 80% of outcomes are influenced or determined by 20% of activities or factors For instance, 20% of product categories generate 80% of the total profit, or 20% of machines incur 80% of maintenance expenses Given its widespread applicability in various situations and conditions, this principle is extensively utilized in numerous fields, including inventory management, finance, and project planning among others.

Source: D R Kiran (2017)Figure 2.5: Pareto principle

Similarly, D R Kiran in 2017 indicated that in the context of Total Quality Management (TQM), the Pareto Principle suggests that 20% of the causes result in 80% of the total machine downtime Thus, directing efforts towards this critical 20% can resolve 80% of the issues.

2.2.3 Cause and Effect Diagram (Fishbone Diagram)

The Ishikawa Diagram, also known as the Cause and Effect or Fishbone Diagram due to its resemblance to a fish skeleton, is a visual tool developed by Kaoru Ishikawa for quality control in product design and defect prevention It graphically represents the complex interplay of causes for a specific problem or event, making it applicable to any type of problem and adaptable to various circumstances The diagram encourages system thinking through visual linkages, keeps discussions focused on current issues, and involves the workforce in problem resolution It's straightforward, easy to learn, and helps prioritize further analysis and corrective actions Each cause on the diagram is a source of variation for the phenomenon under study, making it an effective tool for identifying potential factors causing an overall effect.

The Ishikawa Diagram is beneficial for problem-solving across various industries. Specifically, in the manufacturing industry, the categories of the Fishbone Diagram, according to the Toyota Production System, are known as the 6Ms However, Management (money power) and Maintenance have been added later, expanding it to the 8Ms It's important to note that this expansion is not globally recognized.

Machine: the equipment, tools and technology used in manufacturing processes.

Method: Process or procedure followed to manufacture the product.

Material: Raw materials, consumables and information

Manpower: human resources (including their skills, training and experience)

Measurement: metrics and standards used to evaluate the manufacturing processes

Milieu/mother nature (Environment): external factors that can impact the manufacturing process.

According to David W Scott (2010), he provides a historical perspective on the development of histograms He explains that histograms provide a graphical summary of a random sample and an estimate of the underlying probability density function (pdf) The data points are tabulated into a list of disjoint bins He emphasizes the significance of the histogram's invention in the seventeenth century, marking the transition to modern statistics Before this, statistical data was presented in lists or summaries by category, providing more of an inventory than any deep understanding. Scott uses the example of an analysis of causes of death in seventeenth-century England to illustrate this point He also highlights the work of Graunt in 1662, who analyzed the age of death from the bills of mortality and made a table, marking the beginning of survival analysis by mortality tables.

On the other hand, Behnam Neyestani focuses on the practical application of histograms in modern contexts He describes histograms as a useful tool for visualizing both attribute and variable data of a product or process Neyestani emphasizes that histograms assist users in showing the distribution of data and the amount of variation within a process He also points out that histograms display different measures of central tendency such as mean, mode, and average.

Source: G, Paliska & Pavletic, Dusko & Sokovic, Mirko (2007)

In conclusion, both authors agree on the fundamental purpose and function of histograms but approach their explanations from different perspectives - Scott from a historical viewpoint and Neyestani from a practical application standpoint.

Figure 2.6: Histogram of claims on wet cement bags

The Control Chart, also known as the Shewhart Chart, plays a pivotal role in statistical quality control The concept of statistical control and the control chart were first introduced by Shewhart to achieve a state of statistical stability The primary use of Shewhart Control Charts is twofold and serves two distinct purposes:

Achieving Statistical Control: This involves collecting appropriate data and testing them against trial control limits to determine if a process has reached a state of statistical control.

Maintaining Current Control: This involves testing data against control limits that are computed from a given standard to maintain the current control of a process. These charts are instrumental in monitoring process quality and introducing necessary adjustments, thereby ensuring efficient operation and high-quality output.

A Control Chart is typically composed of a center line, an upper control limit, and a lower control limit, as depicted in Figure 2.7 Occasionally, for the user's comprehension, the chart may also display the upper and lower specification limits. When it comes to defining control charts for variables, there are several commonly used types:

PDCA

The Plan-Do-Check-Act (PDCA) cycle, alternatively known as the Deming or Shewhart cycle, is a methodology rooted in lean manufacturing It was conceived in the 1930s, a time when exclusive products were becoming less prevalent and a new focus on quality management and competitiveness was emerging in the global market. The original PDCA cycle was the brainchild of American statistician Walter A. Shewhart However, it was William Edward Deming who developed this method in the 1950s into what is now one of the most globally recognized and applied

Figure 2.10: Stratification methodologies Initially, the PDCA cycle was utilized as a tool for product quality control However, it quickly gained recognition as a method that facilitated process improvements at an organizational level.

Today, the PDCA cycle is characterized by its approach to continuous improvement and is acknowledged as a logical program that enhances activities Many authors argue that the PDCA cycle transcends being a mere lean manufacturing tool. They contend that it is a philosophy of continuous process improvement ingrained in a company’s organizational culture, with a focus on continuous learning and knowledge creation.

The PDCA cycle comprises four stages:

Plan: This stage involves identifying opportunities for improvement and assigning them priorities The current state of the process under analysis is defined using reliable data, the causes of problems are determined, and potential solutions are proposed.

Do: This stage aims to implement the action plan, select and document information It also takes into account unexpected events, lessons learned, and knowledge acquired.

Check: This stage involves analyzing the results of the actions implemented in the previous stage A comparison is made between the before-and-after states to verify if improvements have been made and if set objectives have been met Various graphical support tools such as Pareto charts or Ishikawa diagrams can be utilized for this purpose.

Act: This final stage involves developing methods to standardize improvements(if objectives have been met) If data are insufficient or circumstances have changed,the test is repeated to obtain new data and re-test the improvement If the implemented actions did not yield effective improvements, the project is abandoned and a new one commences from the first stage.

AHP method

The Analytical Hierarchy Process (AHP) is a versatile method employed across various industries such as economics, politics, and manufacturing This method aids in identifying the most significant criteria among a multitude of factors, or assists in selecting the optimal option based on these criteria.

The Analytical Hierarchy is devised by Saaty in 1990, is a potent tool for addressing intricate and ambiguous decision-making problems It has been combined with the Delphi technique to form hybrid exploratory methods, which have been widely used by various researchers to examine managerial perspectives on crucial factors (Min, 2015; Wong et al., 2021) In a study conducted by Nguyen Thi ThanhVan et al.in 2022, the authors used AHP method to discern the critical factors in the implementation of the TQM 4.0 model.

CONTAMINATION MANAGEMENT CYCLE DEFINITION AND

Contamination Management Cycle Definition and Concept

Contamination is known as contaminants (like cloth fiber, carton or any contaminant) that can be detected visually (not by optical instrument) Contamination on product is contamination on element, loopset or assembly that can be visually detected.

Contamination Management Cycle Standard Elements:

Contamination management cycle is a standardized method to control the contamination in shop floor area CMC gives a transparent data and actions to improve cleanliness condition systematically With these actions, the project team intent work on this project to minimize risk of contamination to ensure product quality as well as customer satisfaction.

Table 3.1: Contamination Management Cycle elements

A database of contamination collected in area where we apply CMC.

Daily record of contamination collected on shopfloor area where apply CMC.

Workflow to collect and analyze contamination: CMC team will decide, refer next section.

Frequency to collect and record: CMC team will define based on situation.

Repeated contamination: If collector detect contamination, which is already in the commination code table, record the data and may or may not keep the contamination sample.

Abnormal contamination: If collector detect new contamination, which is not in the library, record the data and must to keep the contamination sample to analyze and add to library and to contamination code table

Update data from contamination count to daily chart.

Visual the contamination category detected each day.

Visual monthly result (if data available).

Visual the contamination target (daily, monthly).

Daily monitor in CMC meeting, reason for not achieving target is noted and reaction in OPL.

Weekly define and update top contamination of defined period in pareto analysis with clear contamination code.

Top contamination should be prioritized to eliminate by problem solving/ PDCA.

Customer incident relevant to contamination (if any) must be discussed in CMC meeting and priority to solve.

Use problem solving to analyze the root causes and define measures to eliminate the problem.

Problem solving method follow instruction of Systematic of Problem Solving at HcP.

Daily review and update status on CMC meeting.

PDCA Update top contaminations and measure to eliminate with person in charge, target and timeline.

Periodic monitor, review and update PDCA in CMC meeting.

Check for participant of meeting members MFO1

Use OPL for recording reasons for not achieving daily target and quick reaction.

Use OPL to record and track actions, which need to be done for CMC project.

Daily monitor and track OPL.

Checklist to confirm that CMC project is running according to standard and have good result.

Source: MSE1 department of Bosch Vietnam Co., Ltd

Contamination can create high risk on quality In the MSE1 department,contamination management cycle is applied in the mixing process, washing process and supermarket But in the mixing process, the machine behavior is just mixing the elements together to create a perfect combination to produce a good belt, so contamination cannot affect the quality issue at mixing process, but at washing process it can affect Lastly, supermarket does not have quality gate at MSE1, so if the contamination appears in the supermarket, it will be detected at MSE3 and can be count as quality issue from MSE1 These are acceptance standards at the Washing process.

Table 3.2: Acceptance standard at Washing process

Group Abnor mal Identification Control Reaction

Drop/moisture in surfaces of element

Visual (without tool/ magnification ) in lighting condition 800+-100Lux

Element surfaces have brown or black spots

Visual (without tool/magnific ation) in lighting condition 800+-100Lux

Rust/brown spots in hole, or on other surfaces of elements

Visual (without tool/magnific ation) in lighting condition 800+-100Lux

Source: MSE1 department of Bosch Vietnam Co., Ltd

Source: MSE1 department of Bosch Vietnam Co., Ltd

There have been 30 contamination cases which came from manufacturing departments System-CIP project was created in order to reduce and mitigate the risk that comes from manufacturing processes and then make a standard to maintain the cleanliness of the production process With the initial conditions, contamination management cycle is not available at these process except from the Flowline process from the MSE3 department:

All level was not involved in the contamination management

There is no process confirmation or effectiveness check of contamination management

There is no frequency to maintain the contamination management

Figure 3.1: Pictures of Acceptance Standard at Washing process

Figure 3.2: Contamination case on product timeline from 2022 to present

The team members all apply contamination at three production departments: Element production, Loopset production and Assembly This thesis only focuses on the CMC at the MSE1 department.

Deciding which process will be applied CMC is a crucial step because the resource is limited and there are some processes that are not needed to do.

In the production process, contamination management is an important factor to ensure product quality However, due to limited resources, the team cannot apply contamination management to all processes Therefore, there is a need to identify which processes have the highest potential for contamination occurrence and prioritize applying contamination management to those processes.

In this case, we can see that in the fine-blanking process, hardening process and deburring process, there is no possibility of contamination existing in the product The fine-blanking process is the process of stamping raw materials and contamination can appear in the fine-blanking process The hardening process is a closed process so there is no possibility of contamination and hardening can burn and eliminate contamination. The deburring process will use stone, water and chemicals to wash away contamination.

However, in the mixing process, if there is contamination, there is a possibility of its existing in the product and leading to the washing process causing the product to turn yellow and have stains Therefore, we should prioritize applying contamination management to the mixing process and washing process to ensure product quality.

If contamination appear in the product, when it is brought to the supermarket and then passed through the assembly department, it will be considered as contamination on the product This means that if the product is contaminated, it will not ensure quality Nonetheless, managing contamination during production remains very important to ensure product quality.

With all the reasons above, contamination management cycle is applied at the EoL-Supermarket, which means from Mixing process to Washing process and to the Supermarket.

Based on the contamination case before, 30 cases in 15 months with the average of 2 cases per month The project goal is to reduce contamination case to 0 case per month with the deviation of 1 It means that the project to is to reduce contamination case to 0 case or 1 case per month.

First, the project leader will establish the project's background, outlining why the application of contamination management in the MSE 1 area is necessary and for other members to have motivation to do this project Subsequently, the project's goals will be set, specifying the deliverables to be achieved Moreover, these objectives must be aligned among the three departments: MSE1, MSE2, and MSE3.

Next, a meeting will be organized with the team leaders to discuss sample collection for input data and sample analysis The project team will then go to Gemba to identify the sources of contaminants and Khang will complete the contamination matrix

With the data collected, the team will set a target ppm level They will also define the process flow and response plan, followed by creating a RASIC chart Lastly, addressing the source of the contaminants will be a priority.

Subsequently, the validation phase will commence The process engineers will write work instructions for the CMC project and provide training to the workers on contamination collection and cleaning procedures.

Ultimately, once the solutions have been implemented and standards are established, the project will be handed back to the production department, ensuring the new standards are upheld.

Contamination measurement at Mixing, Washing and Supermarket

After defining the problem, the project team decide to collect data about the contamination status at these areas This is the workflow to collect data and analyze contamination:

3.2.1 Process of collecting and analyzing contamination

- Arrange time with operator every shift to collect sample

- Update information into contamination code table and CMC record files

- Meeting CMC according to the frequency

- Collect sample every shift/ fill in the full information

- Time: after mid-shift meal, in 10 minutes

- Store sample: at the trolley in CMC board

- Send sample to QMM3 when shift leader requests

Figure 3.4: Workflow of the contamination management cycle

Operator will go through the whole Mixing process, Washing process andSupermarket with the frequency 1 time per shift About the collection method,operator will wear gloves to pick-up sample, put it into Zip bag with clear recording of position, line number on the label#1, with the small contaminant operator will use clipper to pick up tidy contamination chip and finally change new gloves after finish task.

When operator found contamination, report it to shift leader After that, shift leader will go to Gemba to confirm the contamination whether it is already exists in the contamination code table If it exists, Shift leader will input data and update the Contamination chart and other file relate to CMC If it does not exist, Shift leader will inform to QMM3 technician to make lab order in order to check if it exists in the QMM6 library or not If it exists in the library then QMM3 technician will update contamination code table and Shift leader will update the Contamination chart and other file relate to CMC Then if it does not exist in the library, the project team including MFO1(Supervisor and Shift leader), QMM3 technician and MFE1(line engineer and process engineer) will go to Gemba together to find the suspicious contaminant with the same physical characteristic and QMM3 technician will make lab order to investigate more about the source of contamination If the project team can find the source of contamination, QMM6 will update the library and QMM3 will update the contamination code table Finally, if the project team cannot find any contaminant that does not have the same physical characteristic, QMM6 will update into the “Unknown source” library.

This is the RASIC Chart (Responsible, Accountable, Supportive, Informed, and Consulted) of the System-CIP project.

Confirm it is in library - R - - - - -

For the collection of contamination sample, MFO1 will be in charge of the operation of people like operators to collect sample and Supervisor, shift leader is the one to confirm the task is done So, all the departments related to the project will be informed about the collection.

For the data input, MFO1 will also be the person responsible for this and because of the frequency of collection, there is no need to inform to other departments.

For the lab order making, QMM3 will be responsible when the contaminant was not found in contamination code table.

For the sample analysis, when the sample is analyzed by QMM6, MFE1(Line engineer and Process engineer) will be informed MFO1 and QMM3 will be the one consulting this Because they always face with the shopfloor problem every day and their expertise will be the thing that help to find the source of contamination.

For the contamination code table update, QMM3 will be the one update if there is a new contaminant and after that it will be used for the contamination count.

For the library update, QMM6 will update if the contamination has a source or not If the team cannot find the source of the sample, QMM6 will consider it as an

“unknown source” contamination and all members of the CMC project team will be informed. contamination code table

For the contamination chart update, shift leader will update it per shift after the sample collection if it is in the contamination code table and line engineer will be informed to follow daily contamination status.

For the data analysis, Line engineer will start to analyze that the contamination at which area, which contaminant contributes the most that affect the contamination status and both members from MFO1 and MFE1.1 will support to investigate more about the contamination.

For the PDCA, MFE1.2 will update the status of each task to eliminate or to reduce the contamination, and other departments will support if it relates to them.

For the CMC documentation, TEF6 will be fully in charge for documenting the CMC project in order to use it in the future.

Figure 3.5: Label for data collection

This is the Label#1 that operator use to collect data about contamination and report to shift leader It contains at which process, that shift leader can know where the position is, the name of contaminant, at the “Collect Position”, it means that at which line MSE recently have four lines: Line 4, Line 5, Line 6 and Line 7 But right now,with the demand and the capacity of the mixing machine, washing machine MSE1 department only use in line 7, meaning that only use mixing line 7, washing line 7 andSupermarket for the whole products.

And with the addition information like date, shift, operator’s name and remark, the project team can know when the contamination appears and can contact to the operator, the “remark” is used to know more detailed about the contamination.

Source: MSE1 department of Bosch Vietnam Co., Ltd

After collecting the data of contamination, shift leader will input all the information from the Label#1 manually into the contamination count form.

Table 3.5: “C” code for material in contamination code table

Plastic Paper Wooden POM Metal Cloth fiber Human Paint

Dust Tape Rubber Leather Insect/animal Food Silicone

Source: MSE1 department of Bosch Vietnam Co., Ltd

These are the materials which exist in the library of QMM6 The project team want to encode all the information about the contamination so as to easy to track and measure So, all the material will be encoded as “C”code.

Source: AuthorSource: AuthorTable 3.4: Contamination count form

This is the whole production area of Mixing, Washing and Supermarket at line 7. The project scope is to ensure the contamination management at the start of mixing process When Operator load the metal bin containing elements on the conveyor, element will go through the mixing machine and be loaded automatically to the washing machine After running through washing machine, the product will be taken to supermarket by forklift used by operator Because of the processes, the project team will divide it into three areas with the code: E01(mixing process); E02 (washing process); E03 (supermarket).

However, the project team recognized some weaknesses and decided to change into an e-form:

Human errors: input manually can cause errors so the data will be wrong.

Time-consuming: shift leader will take a lot of time if they type all the information from the labels.

Figure 3.6: Areas applied contamination management cycle

Not transparent: with this form, the project team can know the contamination but cannot differentiate the contaminants with different source.

In addition, the project team add “Type” cell in order to differentiate contamination with the same material but different source For example, if the contamination with source Type “01” will be different from the contamination with source Type”02” And Type “00” is the code to demonstrate that contamination is not identified in the contamination code table yet After the sample is taken to the lab, QMM3 will update whether it is the contamination with a new Type or still in Type

“00” And to prioritize or to know the urgency of the contamination, the e-form also has a “Where” cells: ”In/On Mae” (means that the contamination was found on the workplace like machine or equipment and it could affect badly to the product quality);

“Other Place” and “On Floor” (means that the contamination was found on other

Figure 3.7: Contamination count e-form places like table, on floor,… so it could not have the impact as on the workplace) The team can prioritize contamination in workplace first to ensure it cannot affect the product quality.

The project team will decide the period for the data collection is from May 29 th to

11 th due to the production condition and the team can collect decent data of contamination from materials and sources.

In the contamination count, one commonly used unit for the contamination measurement is PPM (parts per million) This unit is calculated by dividing the number of contaminants by the good output of that day and then multiplying by 1 million By using PPM, teams can visualize which areas have contamination and how many cases are present in those areas This is because contamination is mainly created by human and production activities, and the PPM unit can reflect how production activities can affect contamination Therefore, using PPM as a unit of measurement can provide valuable insights into the management of contamination.

The contamination code table contains all information about the contamination:

Code: the combination of Type and number, it is used to identify contaminants

Area: area where the contamination was collected

Material: material of the contaminants

Type: to identify the source of contamination with the same material

Category: Explain the material in Type column

Description: Details of the contaminants

Picture: Picture of the source of contamination

This is the contamination count after the data collection Then the data will be transformed into ppm unit and publish it on the dashboard.

At that time, the contamination code table has contamination from nine materials with 17 “known” sources and 12”unknown” sources.

Figure 3.8: Dashboard of contamination in ppm unit

Table 3.7: Contamination count raw data

Root cause analysis of contamination source

Through the data collection, measurements and the lab order results in two weeks, the project team found out that the most contribution of contamination is plastic, metal and paper Moreover, the PPM value of each area is: E01 (2595ppm); E02 (840ppm) and E03 (225ppm) The team investigated more about the “known” sources of the contamination Moreover, the C09 contamination is not investigated since the production activities involves human, machine also tool can create dust.

Source: AuthorFigure 3.9: Dashboard of contamination in ppm unit

Source: Author a C0101: Plastic Zipper on the floor

The plastic zipper bag is a packaging solution used to hold product information papers The bag is designed with a zipper closure mechanism that allows for easy access to the contents inside However, if the operator pulls the zipper too hard, it can break and fall onto the floor This can happen if the zipper is not properly attached to the bag or if excessive force is used when opening or closing the bag. b C0102: Plastic parts in Washing Machine

The team go to Gemba with operator at the washing machine and then recognized that the plastic parts were inside the machine when operator was collecting contamination After that the team confirmed the source of plastic parts was from TEF department’s tool during the maintenance time This was a risky contaminant because it has a high risk that can affect the behavior of the machine, causing error. c C0103: Push button of the pen

The plastic button was definitely from the pen and there were many people who can make that part of the pen fall out. d C0104: Plastic parts from pallet

This plastic parts were from the pallet that contains metal bins of elements and it does not have risk that can fall into the product.

Table 3.8: “Known source” Contamination in plastic

Source: Author a C0501: Metal chip from metal bin

Because the metal bin when contain the elements inside can weigh from 50 to 60 kilograms and one pallet can lift from 9 to 10 metal bins, the motion of lifting up and down by forklift can make the metal scratched. b C0502: Staples

Staples from stationery for operators when doing paperwork task, and it does not have a high risk for the product quality.

Banoros paper is hygroscopic paper on top of the metal bin to absorb any excess moisture and protect the elements from rusting Additionally, if elements come into contact with human hands, they may become susceptible to rusting Because the

Table 3.9: “Known source” Contamination in metal

Table 3.10: “Known source” Contamination in paper banoros paper is used with no standard of replacing a new one, the old banoros paper peel off. b C0202: Label paper from washing machine

The structure of the label paper is designed in a roll form, and when the label printer is operating, it will cut the two edges of the label paper roll This causes the excess part of the label paper to fall outside.

C0601: Cloth fiber from deburr rock pack

This cloth fiber comes from a bag used to hold grinding stones in the deburring process Therefore, it is highly likely that this thread was removed by the operators when using the grinding stone in deburring process, and dropped right at the supermarket when entering it.

When entering Mixing area, everyone must use earplugs This tape is from a bag of earplugs The tape is used to package the earplugs together, and when in use, the user simply pulls on both ends of the earplugs to attach them to their ears Therefore,

Table 3.12: “Known source” Contamination in tapeTable 3.11: “Known source” Contamination in cloth fiber the tape may drop from the moment the user pulls on both ends of the earplugs or when they reuse it.

Source: Author a C0801: Paint form the upload frame in supermarket

This is the upload frame that contains pallets and metal bins of elements in the supermarket Shelves in the supermarket have been damaged due to repeated impacts, causing the paint to peel off The cause of these impacts is due to the operators using forklifts to load goods, and the forklifts collide with the shelves, causing the paint to peel off In summary, the paint peeling on the shelves is caused by collisions from forklifts operated by operators This is a high risk of contamination that can fall on the product because the shelves are directly used to store goods, so the likelihood of paint falling into them is very highC0802: Paint from stopper in supermarket

Stopper is the steel placed underground in order to guide the operator use forklift and load the pallets in the correct position The paint is also caused by collisions of the forklift by operators. b C0803: Paint from forklift

Collision of forklift with frames, stopper in supermarket cause paint from forklift.

Table 3.13: “Known source” Contamination in paint c C0804: Paint from safety barrier in supermarket

Safety barrier is used to as traffic shields to absorb the impact from forklifts and other mobile equipment, reducing the risk of injury or damage Safety barriers can also help prevent accidents by keeping forklifts away from areas where they could collide with other objects or cause damage The paint is also caused by collisions of the forklift by operators.

Because all people who go in to the shopfloor area have to wear safety shoes and the shoes may be worn out after a period of time and the sole peel off.

In normal production activities, hair from human can be found but it does not have a high risk of contamination that can impact product quality.

Table 3.14: “Known source” Contamination in rubber

Table 3.15: “Known source” Contamination by human

SOLUTIONS AND CONTROL METHOD FOR CONTAMINATION AND EVALUATION

Solutions for eliminating contamination source

After defining the root cause and the sources of contamination, the author suggests solutions for all “known” sources and repeat “unknown” sources With each solution, it will include steps to implement and these steps will be updated on the PDCA for the team to follow and have a full information about the solutions.

4.1.1 Define cleaning frequency for human contamination, dust and repeated contamination with “unknown” source

Currently, there is no regular cleaning schedule in place, and contamination of

“unknown” source continue to appear The team implement a regular cleaning schedule using a vacuum cleaner at the end of each production shift after collect samples for the CMC project The project team will determine the appropriate frequency for cleaning At present, the factory has a vacuum cleaner, but there is no separate power outlet available for its use As a result, cleaning has been almost non- existent To address this issue, the project team will purchase an additional power outlet and create a work instruction manual for operators to use the vacuum cleaner at the end of each shift Specifically, after collecting foreign objects, operators will use the vacuum cleaner to clean the production area.

The production area is divided into four production groups, each consisting of five operators Therefore, one worker from each group will be responsible for cleaning with the vacuum cleaner at the end of each shift.

In addition to these measures, shift leader will create an automated schedule on an Excel spreadsheet that will notify operators of their cleaning responsibilities for each shift The shift leader will be responsible for checking and confirming that the cleaning has been completed This is a great way to ensure that the cleaning schedule is followed and that the production area is kept clean and free of repeated contamination.

Overall, the solution addresses the issue of foreign object contamination in a systematic and comprehensive manner By implementing regular cleaning and providing operators with clear instructions and tools to carry out their responsibilities, this can significantly reduce the amount of contamination in the factory.

Upgrade the supermarket: Replace all shelves with new, impact-resistant and rust-proof materials The new shelves will have a similar structure and design as the old shelves, but with new materials that will help prevent paint peeling Specifically, the team will replace the shelves with high-load stainless steel to hold goods The new shelves should have a high load capacity to accommodate the weight of the pallets and metal bins of elements in the supermarket Each pallet can weigh 500-600kg and a shelf must hold 8 pallets, so the load capacity must be up to 5 tons Based on these requirements, the project team will involve other related departments: HSE and FCM to consider about the safety also the quality of the new shelves

Equip pallet protectors: When forklifts collide with pallet protectors, the paint on the upload frames will not peel off With this solution, 12 pallet protectors are needed for 3 shelves and their material must also be rust-proof and highly impact-resistant. Attach bumper pads to forklifts: When forklifts collide with shelves, bumper pads will reduce the impact force and help prevent paint peeling.

Install additional structural pollards: To guide forklift operators to the correct position and prevent collisions with shelves.

Replace stoppers with solid steel materials: When operators collide with stoppers, paint will not peel off and forklifts will not collide with shelves.

4.1.3 Revise all work instruction at production area and create work instructions

Create check sheets during maintenance from TEF: Create check sheet to ensure that after each maintenance and repair, the technical staff in the technical department must clean up the tools and equipment they used during maintenance Operators in the production area will have to observe whether there are any tools or equipment left by the maintenance and repair department, and the manager of technicians will have to fill out a check sheet and sign it to confirm this.

Make one-pager at Mixing area: Make a one-pager reminder that anyone who takes and uses new noise-canceling earplugs must tear open the packaging while taking the tape and throwing it in the trash under the earplugs storage before using the earplugs.

Make work instruction for stationery task: Shift leaders will have to write work instructions for operators to use office supplies only in the office supply area and not elsewhere.

Create standard for using banoros paper: Process engineer will have to create work instructions for using hygroscopic paper and dispose of it when the hygroscopic. paper is damaged or old, along with illustrative images When operators work, they will place an illustrative image right at that area for operators to check if the hygroscopic paper is normal or not.

Contact with purchasing team from Logistics department:

About the label paper, the process engineer contacts the purchasing team in the logistics department to work with the supplier The supplier will come to the factory to observe the current situation and design a new type of paper or change the way the label printer works so that when printing, the excess paper will be stored in the paper tray to avoid falling out Supplier will send a new design for the process engineer and the machine will run a 1-week trial with the new design.

About the plastic zipper bags holding product information being torn at the zipper, the line engineer contacted the purchasing department in the logistics room to work with the supplier to change a new type of bag This new type of bag will not need to use a zipper to avoid tearing the zipper out After changing, information about changing plastic bags will be informed to the entire production department of MSE1 and MSE3 because these bags are used throughout the production process from the start of element production to the assembly.

About the metal chip from metal bins falling out, the process engineer investigated whether metal bins that were cracked and chipped could be repaired or not and contacted a supplier in Germany to buy all new metal bins This is a specialized metal bin for storing products, so it is not possible to change to another supplier.

About the rubber from safety shoe soles peeling off, there are currently two types of safety shoes at the factory The old type has the ability to peel off rubber soles and the new type has different sole materials so it does not have the ability to peel off soles. The MFO1 department contact FCM to replace all new safety shoes for operators in the production area.

4.1.5 Design removable cover for metal bin

Metal chips are one of the main sources of contamination contributing to the Pareto Therefore, the team has come up with a solution: designing a removable cover for the metal bin After the mixing and washing processes are completed, operators will use the cover to seal the metal bin before storing it in the supermarket.

Solutions prioritization using AHP method

The solutions can eliminate contamination sources found However, the company’s resources are limited so the team cannot implement all the solutions. Moreover, with the right solutions prioritization, the project team not only can enhance the project delivery KPIs by ensuring that critical tasks are completed first but also helps to better utilize scarce time Finally, risk management is a must when working on a project so that prioritization is the key to successful projects because it increases the likelihood that a company will execute the necessary changes and create value.

Based on reasons above, the author suggests that with the solutions that can be done with little effort like Define the cleaning frequency; Revise and create work instructions the team will implement immediately With solutions Contact with supplier; Upgrade supermarket and forklift; Design removable cover for metal bin, the author will use AHP method to select only one of three solutions to implement.

After the discussion of the project team also review of sponsor, AHP method will be used to select what solution will be implemented based on five criteria:

Time: the time to implement solutions This measure how long will it take to put each solution into practice It is very important because it can impact the project timeline.

Cost: the initial investment required to implement, the training cost when the solution requires employees to learn new skills or knowledge This will directly impact the budge of the project.

Effectiveness: this will measure the amount of contamination eliminated when implement solution.

Sustainability: this evaluates whether a solution is sustainable in the long term.

Employee’s Capacity: this considers whether employees have the capacity to implement and maintain the solutions, in terms of both time and skills.

The author sent pairwise comparison matrix to five experts These experts are head of department at MSE1, group leader of MFO1 and project team members.

After the data collection from experts, the author can use Consistency Ratio (CR) and Consistency Index (CI) to evaluate the consistency of the data If CR below 0.1, it is consistent After the analysis, the most important criteria are the highest criteria weight.

Source: Author Source: Author Source: Author

With a Consistency Ratio (CR) of 0.0956, which is below the threshold of 0.1, the judgment matrix is confirmed to be consistent As per Table 4, the criteria are ranked in order of importance as follows: Time, Effectiveness, Cost, Sustainability, and Employee's Capacity.

After identifying the most important criteria, the author used AHP method again to choose which is the best solution that fits all the criteria In order to simplify the presentation of the matrix used in this study, the three proposed solutions are denoted

Table 4.2: Pair-wise comparison matrix

Table 4.3: Normalized Pair-wise comparison matrix

Table 4.4: Criteria weights table as follows: 'Upgrade supermarket and forklift' is referred to as S1, 'Contact with suppliers' as S2, and 'Design removable cover for metal bin' as S3.

Source: Author Source: Author Table 4.5: Comparison matrices and local priorities

Table 4.6: Local and global priorities

Upon analysis, the solution to "Upgrade the supermarket and forklift" emerged as the most suitable, outperforming the other two solutions with a criteria weight of

"0.5759" It is recommended that this solution be implemented to not only eliminate the source of contamination but also to mitigate risks on quality in the production area.

Implementation Plan for the “Upgrade supermarket at forklift” solution 62 4.4 Evaluate the solution’s effectiveness and control method by Point-CIP project63

Improving the infrastructure of the supermarket and the forklifts will significantly reduce the risk of contamination from paint materials, which is a major concern for product quality Up until now, the contamination in the supermarket has been traced back to three primary sources: paint from safety barriers, paint from the upload frame, and paint from the forklifts themselves The main cause of this contamination has been collisions between the forklifts and the supermarket, which are often caused by operators during usage.

The detailed implementation plan spans over a week and is as follows:

Day 1-2: These days are dedicated to the transportation of goods and the installation of pallet protectors The finished products in the supermarket will be divided into two categories: the most frequently used products will remain in place, while the least used products will be relocated to a different warehouse with similar conditions Following this, the pallet protectors will be installed.

Day 3: This day is reserved for the installation of structural bollards and stoppers replacement.

Day 4: This day is allocated for the implementation of bumper pads on the forklifts Two days are assigned for the MSE1 department and one day for the MSE3 department Concurrently, the stability of the newly installed pallet protectors and bollards will be checked to ensure they are fit for purpose If any problems or errors are found during the installation, they will be fixed immediately.

Day 5-6: These days will continue the implementation of bumper pads and the checking of the stability of the installed items.

Day 7: On the final day, a thorough check will be conducted to ensure everything is installed perfectly Once confirmed, all goods will be transported back into the supermarket, ready for integration into daily production activities.

By implementing with this plan, it ensures that each aspect of the contamination management project is addressed in a systematic and thorough manner It demonstrates a comprehensive approach to improving the supermarket’s infrastructure and reducing the risk of contamination.

4.4 Evaluate the solution’s effectiveness and control method by Point-CIP project

After the solutions implementation, System-CIP project will be closed and the team will handover it to the shopfloor Point-CIP project will be launched to maintain and control the new contamination standard in three months.

Based on the data collection, the average ppm per day is 406ppm and after the agreement from project sponsor, the team decide the target is 287 ppm, 30% reduced of all areas about the contamination in MSE1.

Using two KPIs to track contamination management will give a more comprehensive view of the current production situation and propose appropriate improvement solutions This approach allows the project team to monitor and control contamination levels By setting clear goals and targets, the project team can effectively measure progress and make necessary adjustments to achieve the desired outcomes.

Figure 4.1: KPI tracking of Point-CIP project

Two key performance indicators (KPIs) to track, which are the Monitoring-KPI and Improvement-KPI:

• Monitoring-KPI: no contamination on the product whose source is from three areas.

• Improvement-KPI: 287 ppm, with a standard deviation of 10% which means

316 ppm and allowing a number of days of failing targets Unexpected issues may arise during production, abnormal contamination may appear and cause the ppm to go up unexpectedly Additionally, there may be issues with the machine that lead to low output, which can also cause the ppm to go high By allowing for these deviations and times to fail the target, the project team will cover the potential for these issues to occur and providing a buffer to address them without negatively impacting overall goals If the ppm unit at that day is higher than 287 ppm but below 316 ppm, it is still considered normal However, if it is higher than 316 ppm, it is counted as one time not meeting the target and there are a maximum of times not meeting If it over the times not meeting the target, the project is considered a failure.

During the time maintaining the new standard, there will be times that the ppm unit is higher than the target and that when CMC team start to troubleshoot the issue.Based on that, the team create a reaction plan to deal with this problem, make the ppm immediately back to normal conditions Based on the data collection, there will be two reaction plans according to their urgency: Reaction plan on workplace and reaction plan on other place.

Reaction plan for contamination on workplace:

At the start of the process, shift leader will update the ppm unit daily and observe if it is higher than the target (316 ppm/day) shift leader will go to Gemba to find the source of contamination

If shift leader can find the source of the contamination, shift leader will eliminate the source and assign operators to clean the contamination then update the contamination was solved in the OPL Otherwise, shift leader will update the OPL that the CMC team will do contamination analysis and troubleshooting.

Figure 4.2: Reaction plan on workplace of Point-CIP project

If shift leader cannot find the source of the contamination, shift leader will send the sample to QMM3 to make lab order for sample analysis Moreover, QMM3 will inform shift leader about the number of lab orders and shift leader will update it on OPL After that, if the lab result can confirm the source of contamination from QMM6, the process flow will be the same as normal Otherwise, shift leader will update the OPL for the “unknown” source of contamination and the CMC team will investigate and make preventive action.

When the problem cannot be solved easily and the CMC team has to join to investigate more In the process of problem-solving, choosing the appropriate method for the complexity of the problem is crucial In this thesis, the author has proposed using the following methods to solve problems based on their complexity

PDCA is used when the root cause of the problem and the source of contamination has been identified PDCA is a continuous cycle consisting of four stages: Planning (Plan), Implementation (Do), Checking (Check), and Action (Act) In the case that the contamination makes the ppm go up over the target, one of the