MINISTRY OF EDUCATION AND TRAINING HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION GRADUATION THESIS INDUSTRIAL MANAGEMENT APPLYING STANDARDIZED WORK TO ENHANCE THE MANUFACTURI
Rationale
In the current market fluctuations, especially in the field of developing powertrain solutions, businesses have been facing an increasingly fierce competitive environment, requiring upgrades, continuously increase value and reputation for customers According to the Global Automotive Powertrain Market Report 2024, Automotive Powertrain Market size was valued at USD 863.87 billion in 2022 and is poised to grow from USD 963.22 billion in 2023, registering a Compound Annual Growth Rate (CAGR) of 11.5% during the forecast period (2024-2031), and the market is projected to be worth USD 2301.03 billion by 2031 To achieve this, taking full advantage of the production capabilities of the business is key To attract customer attention, a business not only needs to commit to product quality but also ensure its sustainability Frank Tyger said, “Professionalism means consistency of quality.” Quality, undeniably, is the decisive factor enhancing product value However, reality shows that during the production process, many businesses still face many challenges and inadequacies, making maintaining and implementing quality standards complicated
To solve these difficulties, one of the effective solutions that has been applied is to use Standardized Work Standardized Work is not only an effective measure to ensure that every product produced is synchronized and of high quality, but it also provides many other important benefits Monden (2015) affirms that Standardized Work, as well as other TPS tools, is based on production time control activities, workforce balancing, quality improvement, and low-er production cost In addition, Standardized Work also helps improve operator performance, making the production process more flexible and the ability to make machine adjustments smoother This not only helps optimize the performance of devices, but also minimizes the risk of errors occurring during the manufacturing process In this way, the production process not only becomes more efficient but also ensures that the final product fully meets quality standards, increases customer trust, and strengthens the brand position of the business in the market
Bosch, with its expertise in the field of powertrain solutions, puts quality first, viewing quality as one of the most important factors in its business strategy Ensuring quality is not only a commitment but also the core goal that Bosch is aiming for In this context, the application of Standardized Work becomes an extremely important and necessary method to ensure that each product meets the highest standards and is consistent in the production process Bosch has been integrating Standardized Work into each of its production processes to improve the efficiency and quality of daily production activities It not only helps limit errors that arise during operation and work, but also optimizes the interaction between components in the production chain This not only creates reliable and efficient products, but also promotes the brand reputation of Bosch in the powertrain solutions industry At the same time, synchronization in the production process also enhances the ability to respond quickly to market fluctuations, keeping Bosch in a leading position in providing quality, efficient, and high yield powertrain solutions
Through an intensive learning and development journey at Bosch, the author became clearly aware of the current production situation at Pipe Line 5 There is a need to develop additional tools to ensure quality in the manufacturing process, through the application of Standardized Work This prompted the author to choose the research topic
"Applying Standardized Work to enhance the manufacturing process at Pipe Line 5:
A case study of Bosch Ho Chi Minh City Plant in Dong Nai" to evaluate the actual situation and implement Standardized Work in the manufacturing process, identifying and eliminating residual waste During the research process, the author set the goal of a detailed assessment of the current production situation at Pipe Line 5, focusing on important aspects such as performance, product quality, and manufacturing efficiency The application of Standardized Work is carefully considered, with the goal of finding opportunities to improve processes and reduce waste Bosch aims for Standardized Work adoption to contribute to 3.5% sales growth this year And this goal will be achieved even higher in the following years After the process of evaluating and analyzing, the author will propose specific solutions to improve production efficiency at Pipe Line 5 of the Bosch Ho Chi Minh City Plant This not only focuses on eliminating waste but also on building a flexible and efficient manufacturing process capable of meeting increasing market requirements and maintaining Bosch's position in the field of powertrain solutions.
Objective
This thesis sets out important main goals: understand and improve the manufacturing process at Pipe Line 5 of the Bosch Ho Chi Minh City Plant Specifically, these goals include:
Understand the current status of the manufacturing process:
Conduct a comprehensive assessment of manufacturing performance and quality at Pipe Line 5 Identify strengths and weaknesses in the manufacturing process and learn about current challenges and opportunities
Identify and define waste, related issues:
Analyze and evaluate activities in the production process to identify value- added activities, activities that do not add value, and activities that bring value to the business Clearly identify waste and evaluate its impact on the production process
Learn and apply Standardized Work:
Research and apply Standardized Work principles to improve efficiency in the manufacturing process Recommend specific changes based on Standardized Work to optimize production steps and minimize waste
Propose solutions to improve production efficiency:
Based on the results of the assessment and identification of problems, propose some specific solutions to improve production efficiency Develop a detailed action plan to deploy and implement the proposed solutions
By implementing these goals, the thesis will not only provide insight into the current state of production at Pipe Line 5 but also propose specific solutions to improve efficiency and reduce waste in the manufacturing process of the plant.
Scope and Object
- Space: Pipe Line 5 at Bosch Ho Chi Minh City Plant, Road No 8, Long Thanh
Industrial Park, Long Thanh District, Dong Nai Province, Vietnam
- Time: The period from January to April 2024
Object: Standardized Work of the manufacturing process at Pipe Line 5 of the Bosch
Ho Chi Minh City Plant.
Research Methodology
Methods of collecting information and data:
The author will monitor production operations at Pipe Line 5 and collect relevant information, including performance, product quality, cycle time, and other key metrics
Use tools that can be deployed to collect accurate and continuous data from the manufacturing process
Statistical methods and data analysis:
The author will use statistical and analytical tools to create charts and visualizations from the collected data This helps create a visual and easy-to-understand view of performance and other factors in the manufacturing process Apply descriptive statistics to describe and summarize important characteristics of data, such as mean, variance, and distribution
The author will synthesize and organize the results obtained from analysis and statistics to have an overall view of the current state of the production process Based on the results obtained, the author will perform a detailed analysis and propose specific solutions to improve Standardized Work at Pipe Line 5
Motion Study was studied by Nielbel B W (1995) in Motion and Time Study The author will use the motion study method to analyze the types of body movements of operators while performing his job Thereby, the author can analyze and eliminate or limit redundant and ineffective activities in the production process
Lean Manufacturing is a production philosophy that reduces the waste time between the workplace and the production process Using Lean to eliminate waste and reduce the overall cycle time and costs is one of the core aims of Lean The author uses these methods with the aim of continuous improvement in production processes, quality, and operations and ensuring optimization of production costs.
Structure of the report
Besides the Introduction and Conclussion, the structure of the report includes:
INTRODUCTION TO THE BOSCH HO CHI MINH CITY PLANT
Overview of Bosch Global
1.1.1 History of formation and development:
The history of Bosch starts with many first steps The step into independence, onto the automotive market, into markets outside Germany, and onto the factory floor of major manufacturing
In November 1886, Robert Bosch (1861 – 1942) opened a Workshop for Precision Mechanics and Electrical Engineering in western Stuttgart with one journeyman and one errand boy The early years were beset with highs and lows, and it was only from the mid-1890s on that things took off quickly and unstoppably From the beginning, it was characterized by innovative strength and social commitment Gradually, Bosch has become the world's leading supplier of automotive technology
In 1897, Bosch started installing better-designed magneto ignition devices into automobiles and became the only supplier of a truly reliable ignition
In 1898, he founded the first Bosch company outside Germany in London with the Englishman Frederic Simms This was the first step into the global market
In 1902, the chief engineer at Bosch, Gottlob Honold, unveiled an ever-better solution: the high-voltage magneto ignition system with spark plug This product paved the way for Bosch to become a world-leading automotive supplier
In 1927, Diesel injection pumps were introduced into automobiles
In 1928, the first electric tool was an electric trimmer called Forfex
In 1929, Bosch subsidiary Blaupunkt announced the world's first car radio This is the foundation for the development of Blaupunkt, the market leader in in-vehicle entertainment and safe navigation
In 1933, Bosch began producing household appliances with the introduction of household refrigerators
In 1958, Bosch introduced the first washing machine
In 1964, followed by the dishwasher The Robert Bosch organization was founded
Bosch has developed continuously until 2023 The Bosch Group is a leading global supplier of technology and services It employs roughly 429,400 associates globally (as of December 31, 2023) The company generated sales of 91.6 billion euros in 2023
Figure 1.2 Key figures and brands as of December 31, 2023
As a leading IoT provider, Bosch offers innovative solutions for smart homes, Industry 4.0, and connected mobility Bosch is pursuing a vision of mobility that is sustainable, safe, and exciting It uses its expertise in sensor technology, software, and services, as well as its own IoT cloud, to offer its customers connected, cross-domain solutions from a single source The strategic objective of Bosch Group is to facilitate connected living with products and solutions that either contain AI or have been developed or manufactured with its help Bosch improves quality of life worldwide with products and services that are innovative and spark enthusiasm In short, Bosch creates technology that is “Invented for life.”
Its operations are divided into four business sectors:
- Mobility Solutions: Two-Wheeler and Powersports, Automotive Original
- Industrial Technology: Drive and Control;
- Energy and Building Technology: Building Technologies
The Bosch Group encompasses a number of different brands that are tailored to individual market requirements and whose products and services are also designed to improve quality of life Explore some of these brands below:
Figure 1.3 Some of brands at Bosch
(Source: Website of Bosch) 1.1.4 Values of Bosch:
The mission of Bosch is based on seven central values, reflecting the manner in which the company runs its business: professional ethics in dealing with business partners, investors, employees, and society
Future and result focus: Bosch’s actions are result-focused, securing its future and creating a sound basis for the social initiatives of the company and the foundation
Responsibility and sustainability: Bosch acts prudently and responsibly for the benefit of society and the environment
Initiative and determination: Bosch acts on its own initiative, takes entrepreneurial responsibility, and pursues our goals with determination
Openness and trust: Bosch communicates important company matters in a timely and open fashion, laying the best foundation for a relationship built on trust
Fairness: Bosch deals fairly with colleagues and business partners, viewing this fairness as a cornerstone of corporate success
Reliability, credibility, and legality: Bosch promises only what it can deliver, accepts agreements as binding, and respects and observes the law in all business transactions
Diversity: Bosch appreciates and encourages diversity for the enrichment it brings and sees it as essential for success
By acting in an economically, environmentally, and socially responsible manner, Bosch wants to improve people’s quality of life and safeguard the livelihoods of present and future generations Bosch aims to make renewable energy more affordable and mobility even safer, cleaner, and more economical, and to develop eco-friendly products across the board
Bosch pursues its vision of sustainable, safe, and enjoyable mobility Bosch
“New Dimensions – Sustainability 2025” target vision translates this ambition into concrete terms Derived from the megatrends affecting its company and the findings of materiality analysis, these objectives set the frame for activities in the years ahead
Bosch is motivated by the desire to develop products that are “Invented for Life” that spark enthusiasm, that improve quality of life, and that help conserve natural resources “We are Bosch” – our mission statement reflects this It summarizes Bosch’s values, strengths, and strategic orientation It shapes Bosch’s corporate culture, ranging from a focus on the future and earnings to cultural diversity Responsibility and sustainability are part of this set of values and, thus, of actions
Objective: In the spirit of Robert Bosch, Bosch aims to secure the company’s future by ensuring its strong and meaningful development and preserving its financial independence;
Motivation: “Invented for life” - Bosch wants products to spark enthusiasm, improve quality of life, and help conserve natural resources;
Strategic focal points: Focusing on customers, Shaping change, Striving for excellence;
Strengths: Bosch culture, Innovation, Outstanding quality, Global presence; Values: Future and result focus, Responsibility and sustainability, Initiative and determination, Openness and trust, Fairness, Reliability, credibility, legality, Diversity, Equity and Inclusion
1.1.6 Quality Gates & Mindset of Bosch Ho Chi Minh City Plant:
Quality Gates: 100% Check station in production
Quality Mindset: On Board Training; Material Improvement; Facility Improvement; Quality Mindset for Operators; 14Q; Saturday Line Walk; Layered Process Confirmation (LPC); FMEA Walk.
THEORETICAL FRAMEWORK
Theoretical Framework about Standardized Work
Pham Huy Tuan and Nguyen Phi Trung (2016) articulate Production is the process of converting inputs into outputs Input factors include human resources, capital, techniques, and raw materials Output includes both products and services This transformation is a central and pervasive activity of the production system It is represented by a simple diagram, as follows:
(Source: Pham Huy Tuan and Nguyen Phi Trung, 2016)
In order for the production process to be maintained and operate effectively, businesses often pay special attention to production efficiency Productivity can increase based on increased output in production, but less input is used That helps increase the enterprise's production productivity when:
- Produce more output but use the same amount of input;
- Produce a constant amount of output but reduce the amount of input;
- Produces more output while using less input
Production is considered one of the main functions of an enterprise and is governed by the purpose of the enterprise Therefore, the role that production aims to play is to ensure maximum satisfaction of customer needs based on the most effective use of input factors in production Example:
- Ensure the quality of products and services according to customer requirements in the right quantity, quality and time;
- Meet the highest quality standards to attract customers and create a competitive position for businesses in the market;
- Optimize production processes, increase labor productivity, reduce waste, and thereby reduce production costs to create a unit of output to the minimum level;
- Shorten product production time, avoid shortages and slower delivery than expected;
- Build the enterprise's production system with high flexibility, exploiting maximum resources effectively
Standardized Work is the basic tool that lies at the foundation of the house in TPS House Standardized Work is an essential element of Lean Manufacturing, it helps production activities to always be performed in a consistent manner
(Source: The Institute for Social Innovation)
Nurul Hayati Abdul Halim et al (2015) underscore that one of the most effective lean techniques is Standardized Work, which may be used to determine the optimal and most dependable work practices and sequences for every piece of equipment, worker, and process It is a tool used in pull production and cellular manufacturing to maintain production tempo in sync with client orders while allowing workers to effortlessly shift places within the process The clearest and most thorough specification and communication of production procedures and instructions are beneficial Julio Cesar Fin et al (2017) emphasized that Standardized Work is an effective way for process improvement, especially when it is applied to manual tasks such as assembly lines
Like all the Lean Manufacturing methods, Standardized Work aims to minimize waste while maximizing performance in the workload and operation of each worker during the production process It helps the process to be more streamlined and standardized based on process documentation for operators in the line In short, Standardized Work means defining who does the task, when they do it, and how they do it When Standardized Work is not applied, OPs on the operational work line will not exclude the possibility of the operator performing other activities that are not part of the work system, which causes damage to the company Standardized Work ensures consistency, efficiency, and quality in the performance of tasks and processes It’s included documentation of the current process for all shifts, reductions in variability, easier training of new operators, reductions in injuries and strain, and a baseline for improvement activities Kasul, R A., and Motwani, J G (1997) said that The main objectives are to minimize process variation among the workers, to eliminate unnecessary motion or Non-value-added (NVA) tasks, and to produce a good-quality product safely and economically
According to Lean Enterprise Institute (2003), Establishing precise Standardized Work for operators, based on three elements:
- Takt Time: This is the rate at which products must be made in a process to meet customer demand We need to balance takt time and cycle time to ensure an efficient production flow Takt time allows to detect any abnormal condition and respond accordingly The Takt time is calculated as follows:
Takt time = Available Production Time / Customer Demand
- Work Sequence: Which an operator performs tasks within takt time, as well as the best way to do it During this process, Line Balancing is performed to determine the number of OPs required to ensure the most optimal use of resources and minimize waste
- In-Process Inventory: Including units in machines required to keep and maintain the process operating smoothly During this process, using a Kanban system can help keep excess inventory moving, preventing delays between workstations and OPs
Standardized Work promotes a culture of stability and consistency, allowing organizations to measure performance, identify deviations and make systematic improvements Tapping D et al (2002) articulate that Standard work provides a basis for consistently high levels of productivity, quality and safety
Standardized Work is shown in three basic forms to improve work:
Process Capacity Sheet: This sheet includes basic information such as Name,
Line, Production time, Processing capacity, Cycle time to meet production demands within a timeframe to identify areas for improvement and eliminate bottlenecks;
(Source: Lean Enterprise Institute) Standardized Work Combination Table: This sheet provides details and precision about interactions between operators and machines to balance the workload of them in a production line It permits the recalculation of operator work content as time expands and contracts over time to enhance productivity and continuous improvement efforts;
Figure 2.4 Standardized Work Combination Table
(Source: Lean Enterprise Institute) Standardized Work Chart: This sheet shows where operators and machines are placed in the overall process layout It includes the time it should take and the number of machines needed for smooth work
These Standardized Work forms are used at the worksite to specify precise requirements that need to be followed to ensure product quality.
Some related contents
5S is a method to systematically improve order and cleanliness at the workplace
It can be applied both on the shop floor and in the office area The 5S was developed by Toyota The 5S stand for:
- Clear the workspace of everything superfluous;
- Keep only what is strictly necessary
- Establish a location for each item required in connection to the optimal flow organization;
- Visually identify all locations (mark, label, etc.);
- Everything is clearly labeled and accountable assigned These are the steps involved in straightening or seitoning everything
- Create routine cleaning and inspection schedules for common spaces;
- Maintain a clean and shiny work environment and equipment
- Establish a visually managed work environment;
- Establish team-wide operational procedures;
- Establish visual standards for process control, safety conditions, and operating procedures
- Always seek out ways to improve as a team
Ned Chapin (2003) provides A Flowchart is a graphic means of documenting a sequence of operations Flowcharts serve as a pictorial means of communicating from one person to another the time-ordering of events or actions As a pictorial format, flowcharts have been the subject of both an International and an American National Standard (ANSI, 1970; Chapin, 1979) Flowcharts go by many other names, including block diagram, flow diagram, system chart, run diagram, process chart, logic chart, and iteration diagram
The two main varieties of flowcharts are the flow diagram and the system chart
A flow diagram gives a detailed view of what is shown as a single process in a system chart Flow diagrams and system charts use different pictorial conventions, but also share certain conventions
Check sheets are a frequently used tool in manufacturing S Leavengood and J Reeb (2002) delve into Check sheets are relatively simple forms used to collect data They include a list of nonconformities and a tally of nonconformities Check sheets should also include the name of the project for which data is being collected, the shift when the items were produced, the names of persons collecting the data, dates of data collection and of production (if known), and the location of data collection (e.g., in house or at a customer’s)
Check sheets are designed in many different formats to visually record data and issues related to quality according to symbols about types of errors and defects in the product during the production process Thereby, to evaluate and analyze the quality situation of the product
Table 2.1 A sample for Check sheet
During the production process, businesses use Check sheets to check the reasons why products have defects to find the cause of the problem, collect customer opinions to easily understand the status and update the situation
A Fishbone diagram, also known as Ishikawa diagram, is a diagram that shows cause-and-effect relationships This is a method in 7 QC Tools, a set of quality testing and monitoring tools Mario Coccia (2018) suggests the fishbone diagram for technological analysis A Fishbone diagram (also called Ishikawa diagrams or cause- and-effect diagrams) is a graphical technique to show the several causes of a specific event or phenomenon In particular, a Fishbone diagram (whose shape is similar to that of a fish skeleton) is a common tool used for cause-and-effect analysis to identify the complex interplay of causes for a specific problem or event The Fishbone diagram can be a comprehensive theoretical framework to represent and analyze the sources of innovation A Fishbone diagram is applied here as a novel graphical representation to identify, explore, and analyze, whenever possible, the potential root causes of the source and evolution of General Purpose Technologies (GPTs) Overall, then, the fishbone diagram seems to be an appropriate and general technique of graphical representation to explore and categorize, clearly and simply, the potential root causes of the evolution of technological innovations for an appropriate management of technology
Figure 2.6 A sample of Fishbone Diagram for 4M
(Source: Compiled by author) 2.3.5 5 Whys:
The core question of problem solving, "Why has the problem occurred?" is the starting point for the "5xwhy" (5W) method As part of the Toyota production system, the method likewise stands for a disciplined and acribic procedure A plausible cause is the foundation for its use, and it is crucial to investigate and validate it using 5W
Every additional inquiry that follows the "why" leads ever deeper into the organization and its behavior (permitting) and further back in the process chain or sequence (collaborating) The method's name is derived from an empirical value, which is the number 5 The beginning point, problem complexity, user experience and discipline, and other factors all affect how many steps are needed Depending on the problem's nature and significance, there are a wide range of potential solutions available after each why stage, or deeper cause investigation The more extensive the deeper the analysis The question of whether the appropriate solution eliminates any chance of the problem reoccurring is crucial when trying to identify the root cause of the issue The core cause has only been identified and the 5W chain can be broken if the relevant measure likewise avoids similar causes in terms of cooperating and permitting, both in theory and systematically
(Source: Compiled by author) 2.3.6 Gemba Walk:
SSDSI Blog presents A Gemba Walk is a well-liked Lean Management technique where leaders visit the workplace and engage with people to obtain important insight into the flow of value inside the firm Collaboration between employees and leaders is encouraged by this strategy, which also enables leaders to learn new ways to support their staff members through the use of a Gemba Walk checklist "The real place" is what the Japanese term "Gemba" signifies That is where the actual labor is done Company leaders have a rare opportunity to view the real job and develop trustworthy relationships with other employees by going on a Gemba Walk This is where the "ivory tower" meets the workplace
To perform process validation of material and information flow standards, as well as observe the value stream for potential improvements, Gemba Walk is conducted for each individual line in the regions Production is scheduled periodically depending on the purpose of the business Before performing the Gemba Walk, the person in charge will print out the VSM (Value Stream Mapping) diagram to make it easy for participants to read The Gemba Walk will begin with a review of the OPLs that have emerged The person in charge will then lead the group of participants into the flow to explain and record all the improvement ideas along the way Finally, the person in charge will synthesize and unify the proposed OPLs
According to the Industrial Maintenance Management textbook by Nguyen Phuong Quang (2016), OEE is a typical parameter in TPM (Total Productive Maintenance) This is the most popular standard in the world to measure the productivity and operating efficiency of a machinery and equipment asset OEE helps businesses identify problems in asset usage and maintenance, determine the percentage of production time that is actually productive, and is a standard measure to track progress in correcting these problems
Through the application of this index, the productivity of the entire equipment as well as the efficiency of the production process increase because production does not occur without problems, delays, or reduced production preparation time
Thanks to OEE analysis, we can objectively evaluate the effectiveness of TPM program Also, OEE can help manufacturers achieve international class More specifically, it can benefit four key factors:
- Machinery: reduce downtime as well as equipment maintenance costs and better manage equipment operations;
- Employees: increase labor efficiency and output by improving visibility into operations and empowering operations staff;
- Process: increase output by finding deadlocks;
- Quality: increase quality rate and reduce waste rate
The OEE index will help businesses consider the current state of machinery According to the formula, OEE is calculated based on three coefficients, as follows:
ANALYSIS OF THE CURRENT STATUS OF
Overview about manufacturing process at Bosch Ho Chi Minh City Plant
3.1.1 Workflow of manufacturing process at HcP:
To produce a CVT Push belt, the MSE Department will be divided into 3 main Departments so that areas can be easily divided to ensure complete and accurate management of the production process overview As mentioned in Chapter 1, push belts are made up of elements and two loopsets, so the MSE Department will divide management tasks, specifically as follows:
Figure 3.1 Manufacturing process of CVT Push belt
MSE2 is responsible for managing the lines to create a standard loopset, accordingly, the production process of a created loopset will be simulated as follows:
Figure 3.2 Manufacturing process of Loopsets
Engineers are one of the most important components of the industrial process They will collaborate with all members of the production system, including engineering, maintenance, machine operators, quality control, and research and development Developing a closed production process to transform raw materials into completed goods is the primary goal They also set parameters at the same time to develop and keep an eye on the entire production process For manufacturing to proceed in accordance with the plan and schedule on a daily basis, engineers must:
- Regularly check and maintain equipment operating in the production system;
- Develop documents and rules for using equipment and ensure compliance with established regulations;
- Monitor operating processes and find solutions to optimize production line performance;
- Support technicians to find causes and handle problems when problems arise during the production process, collect data related to the production process, analyze, evaluate and prepare reports;
- Present compiled data and reports to colleagues and superiors;
- Research, evaluate, support the purchase of new equipment and be responsible for installing and arranging this equipment in the production line;
- Assess the risk level of equipment and processes being used in the business This assessment must include factors related to labor safety and environmental impact;
- Regularly evaluate the performance of equipment and processes to ensure quality and production efficiency are always optimized;
- Manage and allocate budget appropriately and effectively, avoiding wasting business resources;
- Redesign equipment or production processes as required;
- Develop new production processes using modern simulation software;
- Supervise all factory operations and ensure safety for production staff
When a mechanical problem arises that is not within the scope of the MSE Department, the Engineers are responsible for raising the issue with superiors to promptly receive support from relevant Departments
A crucial first stage in beginning a product's production is production planning Production schedules aid in providing a detailed explanation of how the company will carry out production from the moment it receives orders until delivery It aids in the company's successful design of synchronized production lines and helps it get the required quality When the planning process is successful, the company will benefit:
- Optimize the use of unnecessary resources: the company will ascertain the precise requirement for raw materials, schedule human resources, and run essential lines in accordance with the business's production flow;
- Guarantee consistently high-quality output: production schedules need to guarantee the quality criteria that the company has decided upon and established while avoiding quality hazards;
- Comply with client specifications in a timely manner, with adequate quantity and quality: prevent product shortages or surplus inventory;
- Reduce risks that may arise throughout the production process: a well-defined plan will help the company lower hazards like a shortage of raw materials or equipment malfunctions;
- Reduce waiting times, transportation times, and extra waste for semi-finished goods during the production process in order to swiftly increase output;
- Reduce production costs by preventing waste in the production process
In order to meet the most thorough production planning requirements, the company has cooperated with Zatco to act as an intermediary in the ordering process Before starting production, Shopfloor will receive signals from the LOG Department through Zatco:
Figure 3.3 Production planning at HcP
(Source: Compiled by author) LOG receives orders:
When customers start ordering products, LOG will receive the order LOG will determine production needs, such as product type and quantity, and delivery time LOG will then collect data about the factory's existing production capacity (resources, running lines, materials, etc.)
LOG will use previously collected data about the capacity of each line to calculate factors that may cause future demand changes and predict the human resources needed for production For example, how many push belts can the lines produce in a day? LOG will provide a production plan so that the shopfloor can run based on the plan LOG will work with relevant parties to calculate the OEE to see whether the OEE allows and has enough capacity to produce according to orders and on schedule This process must include consideration of all relevant factors such as people, production resources, machinery and equipment, materials and quality If necessary, LOG will calculate to open another line to be able to meet the quantity of products required by customers;
LOG needs to define additional product requirements such as standards, specifications, technical requirements and quality control procedures with other relevant departments working together to resolve issues in production topic
LOG will calculate whether the line's capacity can meet the number of products the customer wants or not based on the Excel spreadsheet
Table 3.1 Capacity calculation of shopfloor
LOG sets the product Target when running Planned Operating Time (POT) for a full day of PL5 as 1981 Pipes running full 4 Tracks (condition on Pipe Line 5 without any problems that reduce the POT value) And the OEE efficiency of PL5 can run at maximum capacity of 77.8% The maximum number of Tracks that can run is 4 Tracks (can change depending on the Customer's needs, LOG can adjust the running plan accordingly) However, the table above will more realistically describe problems that occur during production:
- 1-Apr-24: Due to RampUp Line, POT = 953 minutes, OEE value only reached 27.5%, so the number of Pipes produced that day was 466 Pipes;
- 8-Apr-24: OEE value = 44.2% due to issues about O-Loss and T-Loss, so the number of Pipes produced that day was 1,126 Pipes;
- 9-Apr-24: At PL5, there is PM 15 minutes, POT = 1,415 minutes and the number of pipes produced is 1,960 pipes
Thus, to calculate the number of Pipes that can be produced in a day, LOG calculates based on the following formula:
Total number of Pipes = (Numbers of Tracks / 4) x POT x 60 x (OEE / CT); OEE = OEE nominal – (8 x 60 / POT)
The above two formulas only apply to the Target production plan that LOG desires This is the plan that LOG sets out with the expectation that the product will be produced stably and achieve the desired output However, the machine's operation will not be so ideal (The author will analyze in more depth the situations that reduce OEE value in Chapter 3)
MSE Departments will run and adapt the number of products required by LOG They conduct work assignments to determine the tasks that need to be performed and divide them to relevant Departments
Shopfloor will etermine the production schedule based on the spreadsheet that LOG has calculated to ensure the correct time required for each production stage to avoid the risk of goods being delayed according to schedule
Then, they carry out production activities according to pre-deployed plans Always monitor and control production progress, handle arising problems and adjust plans when necessary
After running the product, it is necessary to re-evaluate performance based on actual production results with the plan to determine the effectiveness of the production process During production operations, if any OPL arises, it needs to be resolved and based on that, we can continue improving the production process in the future
The production planning process is a series of steps taken to ensure that production is carried out efficiently and that customer needs are met This process helps
HcP build tight, flexible and effective production plans, thereby ensuring success and competitiveness in the market
The machines at HcP are designed completely automatically It is designed and built to support manufacturing processes efficiently and continuously HcP is designed as follows:
At HcP, safety is the most important foundation in the production environment, helping to protect the health and safety of employees Ensuring compliance with regulations and taking precautions is essential to minimizing the risk of accidents and protecting everyone If workers feel unsafe, they can stop what they are doing immediately
A fully automated production system consists of robots, sensors, automatic control systems, and other automated technology to carry out production operations with great accuracy automatically
Machines, production lines, cutters, measurement devices, and other production equipment combined into a single unit to maximize production efficiency are examples of machinery and equipment systems
Electrical and air conditioning systems:
To safeguard machinery and equipment from temperature and humidity issues, make sure there is a steady power supply and an efficient HVAC system in place
Consists of automated systems for keeping an eye on how machines and production procedures are operating, as well as automated systems for controlling production parameters in response to changes
Maintenance and repair systems are part of the maintenance and repair systems that keep machinery and equipment operating well and lasting a long time
When combined, these elements contribute significantly to the development of HcP, enhancing productivity and enabling prompt customer response.
Overview about current Standardized Work of manufacturing process at Pipe
According to the manufacturing process, Pipe Line is one of the very important processes because, according to the production flow, Pipe Line can be considered the first stage in producing a Loopset If Pipe Line has a problem and cannot be produced, there will not be enough supply to supply the next Lines in the process, or the supply will be slower, resulting in a loss of time for Ring Line and Loop Line Engineers at Pipe Line are responsible for monitoring and supervising the production process on a daily basis so that there are no shortcomings in the process
To create a Loopset, Pipe Line is responsible for producing Pipe, the production process is simply simulated as follows:
Figure 3.4 Manufacturing process of Pipe Line 5
(Source: Compiled by author) Decoiling: This is the main material to produce a loopset, imported according to the material purchasing process at HcP Use the imported coil to put it into the Cutting and Bending machine to push the coil out of the coil
Cutting and Bending: Created by cutting the Coil into sheets according to the specifications of Cutting and Bending machine These upper and lower parameters will be installed and managed by the QMM3 Department The cut sheets will be bent into tubes of specified sizes and go through the next processes
Pipe Washing: Put unwelded charge pipes into the Pipe Washing machine and use chemicals to clean off impurities and dirt
Pipe Welding: Welding pipes into a pipe with complete connections
Pipe Annnealing: Put the welded pipes into the annealing furnace to homogenize
Influencing factors to implementing Standardized Work at Pipe Line 5
Based on Standardized Work of TPS, it requires main contents This procedure is applicable for creating and maintaining Standardized Work in production It can be used together with the work instructions for manual work content Standardized Work at Bosch makes it possible to:
- Development of the best method to fulfill a task;
- Description & Standardization of the method;
- Process confirmation of the standard;
- Management of deviations from the standard
Processes and activities are described precisely and standardized so that they are always performed in the same way and to the same quality ensuring the sustainable establishment of a consistent improvement process in manufacturing
To deploy a complete Standardized Work process, it is required that the factors affecting this implementation ensure that they meet the requirements that Standardized Work is aiming for Factors that can influence Standardized Work implementation are:
Machine release is an important part of the production system implementation and operation process, and it ensures that the equipment used achieves the expected performance and quality The release process often includes testing, quality control, and approval from manufacturing departments before machines are put into use
When there is a problem with the machinery at Pipe Line 5, the operating OPs is responsible for reporting Shift Leaders, so Shift Leaders will rely on the reaction plan to report TEF TEF will go down to that machine to evaluate the machine's condition TEF will consider and classify two cases:
- If the machine needs repair or replacement for unrelated errors and affects quality errors, TEF does not need to release the machine
- If the machine needs repair or replacement for related errors and affects quality errors, TEF needs to release the machine according to the requirements of the release form as follows:
Figure 3.7 Modify of Release sheet for welding machine
When releasing the machine, the TEF and operator need to check the required items in the check list to save changes if they occur on the machine Note: Form Release must be approved by the management level (Shift Leaders) before the machine can run
Release when the power dips:
Machines in Pipe Line 5 rely on Setting Form and diameter to operate If the machine is producing any type of material, it is necessary to change the Setting Form corresponding to that type of material in the machine so that the machine can operate according to the installed program In case the machine has a power dip, engineers need to check the Setting Form and machine structure to see if the machine is damaged or not If the machine is ready, then continue production Then, check the appearance of the pipe being produced by checking whether the color of the pipe is OK or not Conduct release according to Process Documents (PD) to re-measure product value based on the QMM3 Department's evaluation standards
In short, the machine needs to be released before production to check measurement (based on PD Documents evaluated by the QMM3 Department), visuals, and the Setting Form (based on AS Documents) Thereby, limiting the rate of unwanted defective products and avoiding mass blocking and scrapping of goods By following the correct standards, you will avoid quality issues and create many good products However, besides that, some problems also occur during the release process:
- Released but not imported into the system to evaluate according to parameters, but based on experience to evaluate causing numerical errors and failures according to set parameters Because production operates continuously and changes over time, experience is only valid in the past;
- The parameters have changed but have not been updated in the system, so the OP has not been trained yet, so there is a possibility of Release missing a step, causing it to slip through to another process;
- OPs do not follow the PD properly and slip through to another process;
- If SLs trust OPs and sign the Release Sheet without checking it, then the release will not meet the standards
Preventive Maintenance (PM) is performed based on a periodic schedule, aimed at preventing problems and maintaining devices before they fail Periodic maintenance performed by HcP Technics includes inspection, cleaning, lubrication, re-inspection, and replacement of necessary components of Pipe Line 5 machines The objectives of
PM are to increase the life of machinery and equipment, minimize unwanted incidents, and maintain stable performance PM is divided into 2 types:
- Short-term PM: PM 15 minutes, 8 hours, 10 hours (need to replace parts in the machine), done once a week;
- Long-term PM: In the annual PM, carried out according to the previous plan, technicians will stop the machine and open the entire machine to review and check whether the machine has any potential problems or not If the machine breaks down, find parts to replace it If the machine is stable, then make a plan and only need to do short-term PM For example, when PM discovers scratched air pipes, they will replace them to avoid the risk of machine breakdown later
In short, performing maintenance will help machines operate more stably and be maintained better, preventing potential dangers in the production process By conducting periodic PM, we can detect risks coming from machines and promptly repair them, helping to reduce technical problems and increase the life and durability of the machine However, besides some strengths of maintenance, it cannot avoid the current limitations as follows:
Firstly, while waiting for documents to be updated in the system for problems that occurred in the previous line, technicians have not yet been shared, so there may be a risk of repeating errors in the previous line
APPLYING STANDARDIZED WORK TO ENHANCE THE
Standardized Work implementation process
To implement the application of Standardized Work in the production process, HcP has maintained a clear assignment of tasks to each relevant department:
- Responsible for implementing Standardized Work during production or service provision;
- Monitor production performance and encourage adherence to Standardized Work processes;
- Take part in the development, upkeep, updating, designing, and modification of work processes to guarantee consistency, efficiency, and dependability during implementation;
- Assist other departments in implementing Standardized Work standards, enhancing work procedures, and maximizing performance
- Verify that quality standards are appropriately defined and applied within Standardized Work processes;
- Evaluate and test products to make sure they meet quality requirements;
- Conduct quality testing and data analysis to verify that processes are carried out effectively and adhere to quality standards;
- Identify and address quality issues as soon as possible
- Control and maintain appropriate inventory levels to ensure that production occurs continuously and without interruption due to material shortages;
- Ensure that machinery operate properly and do not cause problems;
- Maintenance plans are integrated into the Standardized Work process to ensure consistency and efficiency;
- Maintaining PM standards in Standardized Work helps to identify problems or failures in production equipment and machinery early, providing specific instructions on how to identify and handle problems to minimize downtime in the production stage;
- Ensuring safety during production includes safety procedures and measures related to the maintenance of equipment and machinery to ensure that employees work in a safe and risk-free environment
- Create and create training programs for Standardized Work, taking into account the training's forms, techniques, and content The Standardized Work standards and procedures should be properly reflected in this training session;
- Answer questions and offer specific guidance to help employees apply Standardized Work effectively;
- Conduct assessment and evaluation activities to make sure Standardized Work training is occurring effectively and achieving its goals;
- Introduces Standardized Work processes and standards and provides guidance on how to implement them in a production environment;
- Arranges regular training sessions to provide Standardized Work updates to current employees to ensure that all employees understand and comply with the latest Standardized Work standards and processes
- Ensure that staff are fully trained on Standardized Work standards and have a clear understanding of their roles and responsibilities during implementation;
- Monitor work processes and ensure employee performance throughout the shift and provide constructive feedback to improve performance;
- When problems are encountered during Standardized Work implementation, Shift Leaders need to handle them quickly and effectively;
- Communication and collaboration with other departments is required to ensure that Standardized Work implementation proceeds smoothly and effectively;
- Build and maintain a work environment that supports the application of Standardized Work standards
- In order to boost performance, make sure that staff members receive comprehensive training on Standardized Work standards and are aware of their roles and duties throughout implementation;
- Keep an eye on work processes, monitor employee performance during the shift, and offer constructive comments;
- Respond swiftly and efficiently to issues that arise during the implementation;
- Cooperate and communicate with other departments to guarantee a smooth and efficient Standardized Work implementation process;
- Create and preserve an environment at work that facilitates the application of Standardized Work standards
These departments must work together and aim to apply and maintain standards in Standardized Work implementation to optimize performance and quality of output
Currently, HcP has been deploying Standardized Work to lines under the responsibility of MSE2 Department in general and at Pipe Line 5 in particular Therefore, Pipe Line 5 is still in the process of developing more documents related to the Pipe production process Below are some general comments:
Efficiency and consistency: Standardized Work has to guarantee that every SLs and OPs in Pipe Line 5 arranges and completes their job in the most consistent and ideal manner possible This promotes uniformity in service delivery and production while also helping to boost efficiency
Always maintain: It is crucial to uphold uniform Standardized Work in order to get the greatest results This calls for dedication and ongoing development from the pertinent departments
Challenges in applying: Because Standardized Work involves a lot of paperwork, it will be challenging to maintain and commit to the proper implementation of standards from all relevant departments, which isn't always the best It will also make it tough to change working patterns
Linking with technology and automation: Written Standardized Work is sent to the Manual Master to assist the person in charge in keeping an eye on and updating working standards As a result, using automation and technology can make Standardized Work more successful
Ensuring flexibility and adaptability: Change is a given in a production setting
Implementers of Standardized Work must therefore guarantee flexibility and adaptability to satisfy evolving client and market demands
Ensure compliance with standards: The issued Standardized Work must be consistent with national standards and the general goals that the company is aiming for
Clear assignment and arrangement: Standardized Work needs to be described and allocated, along with who will be in charge in the event of a problem and who will oversee and carry out those tasks to guarantee compliance The process takes place with moderation and uniformity
4.1.3 Workflow to implementing Standardized Work:
Standardized Work must comply with the criteria such as that the content must be simple, clear, and can be described and displayed with images It also helps the management level to check compliance with the Standardized Work standards in the shortest possible time Below is the summary process applicable for Standardized Work implementation:
Figure 4.1 Workflow to implementing Standardized Work at Pipe Line 5
(Source: Suggested by author) Determine goals and scope:
The person in charge must have a clear understanding of the precise objectives and scope (including the processes that require standardization) before creating any Standardized Work procedures
Compile comprehensive information about the steps, timing, and other aspects of the present process that impact quality and performance
To gather information from pertinent staff members and departments, use instruments like direct observations, team meetings, and surveys
Find areas that could use standardization and improvement
Create new, standardized workflows with precise stages, orders, deadlines, and quality standards based on data and analytics
Put the new Standardized Work procedures into effect
Instruct staff members on novel work procedures, guaranteeing their comprehension and ability to adhere to guidelines
To make sure that everyone is creating the same procedures and doing work according to standards, monitor and track the effectiveness of newly
To make sure that process work is being done correctly and upholding performance and quality requirements, conduct routine inspections
Assess worker performance and process feedback to determine the advantages and disadvantages of standard operating procedures
Utilize this knowledge to gradually modify and enhance work procedures, including modifying standards and procedures in response to input and experience
To make sure that Standardized Work procedures are still meeting objectives and quality requirements, maintain and keep an eye on performance
Work processes should be continuously improved and adjusted throughout time to satisfy new and evolving requirements in the corporate environment
This process is a continuous one in which continuous improvements are made to maintain and enhance performance and quality at HcP.
General assessment of the implementation process
Before implementing Standardized Work, the engineers in charge are responsible for monitoring and observing to ensure OPs follow the process mentioned in the Standardized Work document After applying and implementing Standardized Work for a period of time, Pipe Line 5 conducted an objective assessment from many angles:
Since this is essential to assessing the success of Standardized Work implementation, the process engineer recalculated the Cycle Time of the process's activities using the recently applied process documentation By using standardized work, it has been possible to lower the average production cycle time, which has helped to raise output and improve process efficiency
In order to increase product quality, Process Engineers must constantly assess whether or not the output of the Standardized Work matches the intended objectives An examination of rejection rates, anticipated quality measures, etc., is part of this
The Process Engineer's responsibility is to keep an eye on whether the OPs comply with the relevant process documentation to guarantee flawless, error-free operation Make sure that OPs possess the necessary flexibility and adaptability to modify the work process in accordance with the overarching objectives established
In order to quickly make adjustments and take improvements into consideration, Engineers must keep an eye on the level of response and gather input from OPs to see whether they are having any trouble implementing Standardized Work The need is whether or not using Standardized Work impacts their level of enjoyment and productivity at work on a daily basis If this is causing them to feel unmotivated to work, you can bring it up and request a remedy from the appropriate departments, as it might also be an application limitation
When implementing Standardized Work, it is the responsibility of Process Engineers to measure waste indicators in daily work operations By eliminating needless stages, extra materials and resources, and waiting times, Standardized Work can reduce waste in comparison to its pre-implementation state
After implementing Standardized Work, re-evaluating the effectiveness of Standardized Work improvement requires the person in charge to take a comprehensive approach from many aspects, including all factors related to production to ensure that the process applied to Standardized Work achieves the goal it aims at
4.2.2 VA, NVA and NNVA identification:
In the manufacturing process, identifying Value-Added (VA), Non-Value-Added (NVA), Necessary Non-Value-Added (NNVA) can help HcP better understand how to optimize operations and improve overall performance Therefore, these values are simply identified as follows:
VA directly contributes to creating value for Pipe production Therefore, VA needs to be continuously maintained and optimized to ensure that the process at PL5 can optimize the product produced For example:
- Wiping acetone on the cut edge of the Pipe before placing the Pipe in the Pipe Welding machine can reduce the chance of the welded Pipe having errors such as burning, discoloration, and air bubbles on the weld line;
- Checking the appearance and marking errors that appear on the weld line for removal will help reduce the rate of errors that slip through to other processes and ensure the quality of the product produced
NVA not only does not contribute to value creation for Pipe, but also wastes time, resources Therefore, this value needs to be determined and eliminated immediately to optimize performance and minimize production costs For example:
- Waiting time between production stages due to material or tool shortages When OPs on the line do not have enough material needed to continue working, they have to wait until the material is supplied;
- Unnecessary movement of OPs or waiting time for repairs or assembly of components in machinery
Necessary Non-Value-Added (NNVA):
Although NNVA does not create direct value for the product, it is still necessary to maintain quality and comply with standards NNVA should be ensured to be maintained and implemented effectively without creating any unnecessary waste For example:
- Quality inspection and periodic machinery maintenance do not create direct value for the product, but they play an important role in ensuring that the Pipe produced meets the quality and safety requirements for machinery in the work area;
Proposal solution to enhance the manufacturing process at Pipe Line 5
Identify unnecessary or wasteful activities in the work process and put measures in place to reduce or eliminate them This can help optimize performance and increase the efficiency of Standardized Work, below are some specific solutions to help reduce waste in the production process, as follows:
Firstly, optimize waiting time and waste in the production process by redesigning the layout of Pipe Line 5 This can be done by adding one or two Pipe Annealing furnaces to Pipe Line 5 to reduce time Or Pipe Line 5 can change the Pipe Washing machine to Pipe Annealing machine to keep the layout intact Time to push welded charge pipes from Pipe Line 5 to Pipe Line 4 to optimize transportation waste:
Figure 4.2 Rearrange Layout of Pipe Line 5
(Source: Suggested by author) Secondly, only store Pipe samples for testing when absolutely necessary to reduce scrap from testing for the project
Thirdly,create a work environment where waste awareness is appreciated and encourage people to reduce excess waste in the process For example: Using gloves used in production must comply with regulations When leaving the workplace to rest, OPs put the gloves in pre-designed trays and then reuse them when returning to the workplace
Fourth, performing Kappa tests for OPs to evaluate the level of identification of defect modes on the weld seam can help periodically evaluate the ability of OPs to detect defects that can be found on the Pipe To perform the Kappa Test, the engineers can retain Pipes that appear in Failure Mode (eg Protuberance) on the weld line The engineer measures the Width Normal and Width Defect dimensions, then records the data and uses the Box plot to classify the level of Protuberance (1,2 or 3 level)
Figure 4.3 Protuberance failure mode the weld line
The author measured 10 defective pipes and obtained the following data:
Table 4.1 Width dimension metrics on Protuberance
No Width Nomal Width Defect Results
After getting the measurement data, the author subtracts Width Normal from Width Defect to get the bulge size result Then use that result to draw a Box plot chart
Figure 4.4 Box Plot Chart for Width Defect on Protuberance
According to the Box plot chart, the Results have:
+ Values from 0.092 to 0.163 are classified as Level 1 (Light Level);
+ Values from 0.163 to 0.277 are classified as Level 2 (Medium Level);
+ Values from 0.277 and above are classified as Level 3 (Severe Level)
When checking Kappa, OPs will see this error with the eye If all OPs cannot detect the level of error at Level 1, we can consider performing calculations according to the formula of the Kappa test This is to make the decision to accept this error at Level
1 Most OPs cannot detect it after performing the test The purpose is to reduce waste by accepting low-level error modes that do not affect product quality or cause mass scraping
4.3.2 Optimize VA, NVA and NNVA for implementation process:
Optimizing VA, NVA and NNVA activities in the Standardized Work implementation process is considered the key to enhancing the performance and quality of this process These activities are performed as follows:
Regarding VA, optimizing and enhancing this activity can include applying Lean methods to optimize processes, training employees to improve skills and performance, and using technology Automation technology to increase efficiency and accuracy Eg:
Firstly, when wiping acetone on Pipe, instead of wiping the cut line from the left end to the right end and vice versa, OPs can wipe from the middle of the Pipe cut line Cleaning the Pipe is still guaranteed to be fully done, but the following change can help save time cleaning the Pipe to put the Pipe into the welding machine:
Figure 4.5 Before and After changing the way to clean the pipe
(Source: Suggested by author) Secondly, invest in welding seam size measuring glasses on Pipe so that OPs can use the glasses to measure dimensions and check errors more accurately on the welding seam, helping to increase the value of the final product
Thirdly, at each production stage, it is necessary to create each corresponding
PQI document to ensure OPs comply with requirements and work instructions to help operations in the process be consistent and synchronized
Fourth, eliminate unnecessary Temporary Work Instructions (TWI), do not abuse TWI to perform long-term experimental tests This will affect OPs' work workload because they focus on meeting TWI's requirements and neglect production
Regarding NVA, to solve this problem, organizations can take measures such as enhancing inventory management to ensure that materials are always available when needed, optimizing supply schedules to minimize lead time, waiting time, or invest in automation systems to adjust production based on actual material availability Eg:
Firstly, always ensure the stock of Spare parts is ready for production by creating a tracking file of the quantity of stock in stock We can use Excel to create tracking files, a simple example is as follows:
Table 4.2 Stock tracking form in Spare parts warehouse
No Name Quantity Unit Update date Update person Date of import
1 Electrode 200 pc Weekly Tracking PIC Estimated delivery date
2 Nozzle 100 pc Weekly Tracking PIC Estimated delivery date
3 Gas Diffuser 2 pc Weekly Tracking PIC Estimated delivery date
4 Liner 1000 pc Weekly Tracking PIC Estimated delivery date
5 Contact Tip 200 pc Weekly Tracking PIC Estimated delivery date
When the stock drops to the level measured according to the latest forecast, the tracker is responsible for raising it to promptly find the best solution
Secondly, check the AM Standard at the beginning of the shift to limit machine damage midway and avoid wasting time waiting for machine maintenance This eliminates or minimizes time waste and increases the efficiency of the production process
Thirdly, At each shift, the Pipe Washing machine will have to reject nearly 30 pipes due to dirty pipes (not washed cleanly, with oil on the pipes) So every day, the average number of pipes rejected is about 80
Figure 4.6 Quantity of Reject Pipes before Rewashing