ABSTRACT The purpose of this paper is to explore the benefits of implementing six sigma and its methodology DMAIC (Define, Measure, Analyze, Improve, Control) to improve the quality of Styrofoam shells. The Styrofoam department had the highest defect rate of 0.91% compared with other production departments. The goals of this project are, therefore, to identify quality problems of Styrofoam shells in the Styrofoam department, to find out the root causes of quality problems and to suggest and implement solutions and then evaluate their effectiveness. In the Define phase, Pareto analysis shows that there is one defect that occur most in the Styrofoam shell production process, namely structure. In measure phase, a process capability study was conducted to measure current process performance before improvement. The result of the current process study was incapable and thus it needed to be improved. By applying Fishbone diagram and Brainstorming method in the improve phase, the author determined the root causes of structure defect: Difficulty in controlling the extent of bead expansion; Deterioration of expanded bead pump hoses; Conveyor belts do not have protective barriers; Poor layout; The quality of the raw beads is not uniform in each batch; High humidity. In improve phase, the solutions recommended correspondingly with the 6 root causes: Making expansion density table; Make pump hoses maintenance plans; Install weld fences for conveyor belts; Divide the storage area into two areas, the area for raw beads and the area for the expanded beads; Strictly control the raw bead batches; Using dehumidifiers. However, after conducting an effortandeffect analysis, the improvement using dehumidifiers was removed due to its low effect and high effort. After a process improvement has been done, the result is an increase of 0.4 sigma level from 3.77 to 4.17, which results in the expected cost savings of VND 264,939,140 per year. In the Control phase, a control plan was established to control and monitor the process to sustain improvement efforts.
GENERAL INTRODUCTION
RATIONALE OF THE STUDY
Manufacturing companies, which were heavily affected by the US-China trade war in the past two years, were once again affected adversely when the COVID-19 pandemic spread around the world The decline in consumer demand for goods increases the challenges for manufacturing companies As a result, factories across countries in many continents, from the US to Europe and Asia, all faced a decline in output in the past months The competition between businesses is getting fiercer, companies are under greater pressure when customers become more and more demanding, requiring manufacturers to constantly improve in design, materials and technology to improve productivity and quality to meet orders with less and less time and cheaper prices.
Long Huei Vietnam is the top-quality helmet manufacturer in Vietnam with nearly 20 years of experience in manufacturing motorcycle helmets, owning many famous helmet brands in Vietnam as well as abroad such as Andes, Sunda, Zeus, Cromo, etc. However, at present, the company is facing fierce competition from domestic and global enterprises, especially cheap fake helmets from China.
Based on the data of the defect rates in six production departments (see more detail in Appendix A), the Styrofoam department possessed the highest defect rate (0.91%) and the lowest sigma level (3.86) compared with other production departments (Figure 4.6)
Defect rate & sigma level of production departments
Figure 1 1 Defect rate and sigma level of production departments
This means that the quality problem of Styrofoam department has become more serious and this department has given priority to improvement project In addition, currently there is not any project that has been undertaken with the aim of improving the ratio of the semi-finished product effectively and maintaining the stability of the Styrofoam department
The DMAIC approach is the most common approach in Lean Six Sigma implementation However, DMAIC is not exclusive to Six Sigma and can be used as a framework for applications to improve, optimize production management, improve product quality, reduce costs, improve overall efficiency process or increase productivity DMAIC is a five-step systematic approach that allows quality analysts to efficiently manage process improvement projects DMAIC stands for Define, Measure, Analyse, Improve, Control There are a large number of successful examples of implementing DMAIC in improving the quality and cost minimization such as Motorola, General Electric, Honeywell, Sony, Caterpillar, Ford, LG, etc
Based on practical factors of problem, scale, current conditions, the DMAIC cycle incorporates quality tools which is the most suitable method to improve the quality of Styrofoam shells at Styrofoam department As a result, the author decides to conduct the topic “Quality Improvement of Styrofoam Shells by Using DMAIC Process at
OBJECTIVES OF THE STUDY
Identify quality problems of Styrofoam shells in the Styrofoam department
Find out the root causes of quality problems
Suggest and implement solutions and then evaluate their effectiveness
SCOPE OF THE STUDY
Research location: Styrofoam department, factory 3, Long Huei (Vietnam) limited company, Kim Huy industrial park, Binh Duong
PRACTICAL MEANING OF THE RESEARCH
For Long Huei Vietnam company:
- Help the company and all employees understand the benefits that Six Sigma could bring, and improve teamwork efficiency through a DMAIC project
- Identify the problems that are being encountered in the Styrofoam department, and propose some recommended measures to improve the problems and quality control plans.
- Apply knowledge of Six Sigma and DMAIC process, knowledge about quality management which has been learned into the practice of the company.
- This is also an opportunity to help the author be able to collect, aggregate and analyse data, as well as be able to use the knowledge learned in solving the problems in reality.
LITERATURE REVIEW AND METHODOLOGY
LITERATURE REVIEW
Figure 2 1 What is Six Sigma?
Six Sigma is a systematic methodology for process improvement based on statistics to reduce the error or defect rate that is minimized to 3.4 per million defect possibilities by identify and exclude sources of variation (instability) in manufacturing and business processes In defining defects, Six Sigma focuses on establishment through the deep understanding of customer requirements, and therefore, customer orientation is significantly high.
The Six Sigma methodology system is based on a process called DMAIC:
Six Sigma is not a quality management system, measuring product quality like ISO 9001, or a quality certification system This is a methodology that helps to reduce product defects based on process improvement This means that instead of focusing on checking defects on output products, enterprises should focus on improving production processes and finding out the causes of defects, adjusting appropriately so that defects do not occur.[CITATION Hen00 \l 1066 ]
The Six Sigma story originated in the 1980s at Motorola In the year 1983, a prestigious engineer named Bill Smith came up with the conclusion that checking and testing cannot detect all of the product defects, but customers are ones who can discover the defects, and the defect is the cause of the product failure Due to the number of defects in the process was much more than the number of defects from completed product tests, so Smith decided that the best way to solve the problem of product defects is process improvement to minimize or eliminate the possibility of defects He sets standards 6 Sigma – 3.4 defects per million opportunities or 99.99997%, almost perfect and turns this principle into a method This Six Sigma method has been promoted at Motorola and helped it save more than $16 billion over
15 years Later on, a large number of companies, ranging from General Electric, Honeywell, Sony, Caterpillar to Johnson Controls, have applied Six Sigma and gained remarkable benefits [CITATION Pan00 \l 1066 ]
Although Six Sigma is not widely common in Vietnam, a few foreign-invested companies such as SONION, American Standard, Ford, LG and Samsung have applied the Six Sigma program.
Ford Vietnam is one of successful examples of applying Six Sigma in improving process In 2000, Ford Vietnam Company started implementing Six Sigma in 200 projects to improve processes in all areas of production and business As a result, in
2007, Ford saved 1.2 million USD and the customer satisfaction index reached over 90% per year.
One of Ford Vietnam's most successful Six Sigma projects was to reduce the number of imported parts containers in 2005 Waste is identified because the car component boxes in the containers are still abundant space, Ford arranged and made the most of the available space according to the innovative Six Sigma method Although it is just such a small project, it saved Ford $ 150,000 in 2005 and contributed significantly to increasing profits for the parent company [CITATION JAR20 \l 1033 ]
Not only Six Sigma has been universally incorporated into manufacturing and service industries due to the positive influences on quality enhancement and cost reduction but also it has gained much prevalence and acceptance among academic scholars. [CITATION Noo12 \l 1066 ] explored the applicability and suitability of the Six Sigma framework for process improvement of IT industries By applying DMAIC process and several statistical quality control tools such as I-MR chart, Fishbone, C&E Matrix, etc., they found out the roots causes that affected the unsatisfaction of customers towards IT Infrastructure factor Thanks to this improvement project, the volume of customer complaints of IT Infrastructure reduced to 75% One of the most critical problems faced by manufacturers nowadays is that they cannot meet the forecasted demand [CITATION Nic \l 1066 ] performed Six Sigma and Lean to create a better process with more reasonable cost that can meet the customer needs The objectives were to reduce process wastes and optimize production process to increase productivity and competitive advantages of the company [CITATION Ada09 \l 1033 ] applied Six Sigma methodology to find out root causes of power errors through a 2- factor experiment and implement actions to reduce defects [CITATION Hsi11 \l 1033 ] successfully applied steps of DMAIC process to reduce the defect rate of egg cakes by 70% in the food industry At the beginning of the project, the rate of defects was 0.45%, and after implementing improvement actions during six months, the figure decreased to below 0.141%
Six Sigma is a methodology of statistical process improvement with the aim of minimizing error or defect rates to the most perfect extent by identifying and eliminating root causes in processes Six Sigma method focuses on identifying and understanding thoroughly customer requirements; hence it is very customer oriented.
“Sigma” means the standard deviation in the statistics; thus, Six Sigma means six standard deviation units:
Table 2 1 Levels of Six Sigma
Sigma % Accuracy % Defects Defects per million opportunity (DPMO)
Figure 2 2 Illustration of levels of Six Sigma
The goal of Six Sigma is only 3.4 defects per million possibilities of failure In other words, it is about 99,99966% perfect.[CITATION Mek06 \l 1033 ]
2.1.1.5 Advantages and Disadvantages of Six Sigma
There are various benefits that Six Sigma brings to organizations[CITATION Jij04 \l
Six Sigma strategy places a clear focus obtaining measurable and quantifiable financial returns to the bottom-line of a company There is no Six Sigma project approved if the bottom-line influence has been clearly identified and defined.
Six Sigma strategy puts an unprecedented importance on strong and passionate leadership and the support needed for its successful deployment.
Method of solving the problem of Six Sigma integrates the human factors (cultural change, customer focus, belt system infrastructure, etc.) and process elements (process management, statistical analysis of process data, measurement system analysis, etc.) of improvement.
Six Sigma methodology utilizes tools and techniques for improve problems in business process in a sequential and disciplined approach Each tool and technique within the Six Sigma methodology have a vital role in success and failure of a Six Sigma project.
Six Sigma creates an infrastructure of champions, master black belts (MBBs), black belts (BBs) and blue belts (GBs) that lead, deploy and implement the approach
In Six Sigma, it is considered that data and decision making based on facts and data are more important than assumptions and hunches This methodology forces people to conduct measurement.
Six Sigma utilizes the concept of statistical thinking and encourage the application of trustworthy statistical tools and techniques for reducing defects through process variability reduction methods (e.g., statistical process control and design of experiments).
Like any other quality improvement methodologies, Six Sigma has its own limitations, including[CITATION Jij04 \l 1033 ]:
First of all, find out quality data is the challenge of any Six Sigma projects’ analysist, especially in process where no data is available to begin with This is the reason why sometimes the measure phase could account for the largest proportion of the project duration
In addition, the statistical definition of the Six Sigma is 3.4 defects or failures per million chances In service processes, a defect can be identified as anything that does not satisfy the customer needs or expectations It would be illogical if it is assumed that all defects are equally good when we calculate the sigma capacity level of one process For example, a mistake in the hospital could be a false admission procedure, lacking training required by an employee, employee's misconduct, lacks of goodwill to help patients when they have specific queries, etc
The calculation of the error rates or the defect rates is based on assumptions about normality The defect rate calculation for unusual situations have not been properly solved in the current literature of Six Sigma
METHODOLOGY
Chapter 2 Literature Review and Methodology
Figure 2 18 Thesis implementation method 2.2.1 Define Phase
The goal of this step is to find out about the research object, identify problems need to be solved, set goals, and work to be done, and scope of the topic.
Measure the current state of the problem
Analyse possible causes and root causes
Analyse the feasibility of solutions and evaluate them
Find out the root causes of quality problems
Suggest and implement solutions and then evaluate their effectiveness Yes
Method of determining research object: find out overview of the company, research area, problem status
Improvement objectives: set up indicators to measure the success of the project.
Set up an implementation plan: determine the methodology to implement the project, divide the tasks to perform.
The result of this step is to identify research topic, state research problem, define project objectives, research scope.
The goal of this step is to determine the measurement parameters of the system
Measure the types of defects that occur during production process.
Calculate DPMO indexes or defect rates in the process and the impact level.
The goal of this step is to identify the root causes of the current problems
Analysis method: tools (5Whys, Pareto diagrams, control charts ) are used to find the root causes, risk assessment and data analysis.
Collect additional data (if needed) and analyse data
The goal of this step is to apply tools, methods and techniques to address the root causes in order to achieve the initial goal.
The goal of this step is to develop a plan to control, operate, monitor and control the improvement process in line with the set goals.
Implementation method: building a more appropriate technical standard limit, a control plan by building control charts, using process control tools by statistical tools.
General results achieved, results not yet achieved, advantages and disadvantages when doing research, suggest some future research directions.
COMPANY INTRODUCTION
COMPANY BACKGROUND
Name: Long Huei (Vietnam) Limited Company
Factory 1 (Head office): No 33, Lane 1020, Dawan Road, Yongkang District, Tainan
• Factory 2: No 60 Le Thi Trung, Phu Loi Ward, Thu Dau Mot City, Binh
• Factory 3: Lot CN12.CN13, Kim Huy Industrial Park, Phu Tan Ward, Thu Dau
Legal representatives: Li, Ming-Hui
Figure 3 1 Factory 3 in Kim Huy Industrial Park
Long Huei Co., Ltd was established in 1988, specializing in manufacturing and trading motorcycle helmets, with the head office located in Taiwan In 2001, LongHuei Vietnam Co., Ltd was established with the factory located in Kim Huy IndustrialPark, Thu Dau Mot City, Binh Duong Province.
With advanced technology strengths, modern equipment and experienced human resources, Long Huei Co., Ltd always brings to the market products with top quality, diversified design, meeting the needs of domestic and foreign consumers.Long Huei’s factories meet ISO-9002 standard, and apply many advanced technologies in production Products of Long Huei company all meet the standard ofQCVN (Vietnam), DOT (United States), ECE (Europe), JIS (Japan), CNS (Taiwan),SNI (Indonesia)…, which helps the company serve the most demanding international markets such as Japan and Europe.
COMPANY HISTORY
• Long Huei helmets limited company was founded Address: No 33, Lane 1020, Dawan Road, Yongkang District, Tainan City, Taiwan
• Established Vietnam Branch Company Address: Lot CN12, CN13, Kim Huy Industrial Area, Phu Tan ward, Thu Dau Mot City, Binh Duong Province, Vietnam.
• Established Andes and Cromo helmets brands.
3.3 BRANDS OF LONG HUEI COMPANY
Figure 3 2 Logo of ZEUS brand
In 1989, Zeus brand was established in Taiwan Zeus brand currently presents in countless countries across all the five continents Thanks to the company’s R&D team, Zeus brand is always ready to respond to the global market demands
Make possible one to explore its own limits
Be the worldwide benchmark for the motorcycle helmet industry.
Adaptability ã Suitable for every necessity.
Proactivity ã Strive to always be one step ahead.
Loyalty ã Faithful in our long-term partnerships.
Excellence ã The quality of being perfect.
Figure 3 3 Logo of Andes brand
In 2001, Long Huei Vietnam branch company established Andes brand Andes is one of the number 1 helmet brands in Vietnam In 2010, because the company wants to serve consumers better, the Andes showroom system was officially established The Andes showroom system includes 15 stores in districts in Ho Chi Minh City and 1 store in Can Tho city.
• Andes wants to steadily develop the brand "kai") meaning change and the word Andes ®"kai") meaning change and the word , always stands at the forefront in the field of helmets and expands international markets.
• Andes builds a strategy to develop modern technology, constantly innovates to increase efficiency, and ensures "kai") meaning change and the word quality, safety, savings"kai") meaning change and the word
• Andes also speeds up brand marketing strategy, maintains and expands markets, makes efforts to find new customers, and explores big markets in Japan, America, etc.
• Sustainably develop with businesses in the helmet manufacturing industry in order to bring many benefits to the socio-economic development of the community.
• Innovate, constantly improve technology, and provide diversified products to meet the needs of domestic and foreign customers.
• Become the best choice for customers on the basis of reducing costs and improving employee living standards
• Promote brand building strategy, maintain traditional customers, exploit new customers, and expand the market under the motto "kai") meaning change and the word for a complete happiness"kai") meaning change and the word
Figure 3 4 Logo of Cromo brand
In 2001, Long Huei Vietnam branch company established Cromo brand Cromo helmets apply European production technology, and they are tested and checked for quality at the factory-located laboratory to ensure that the products meet the national safety standards QCVN: 2008/ BKHCN According to Mr Liu Ying Ju - Factory Manager, currently Cromo brand stopped selling
Figure 3 5 Logo of SUNDA brand
(Source: SUNDA helmet website) Sunda brand was established in 2016 in order to penetrate into the new helmet market in Hanoi In 2018, Long Huei company established Hanoi office and opened a showroom at 247 Kham Thien street, Dong Da district, Hanoi, Vietnam.
To be the standard in motorcycle helmets industry.
Sunda Helmet Vietnam – To be safe on every road.
Adaptability ã Suitable for every necessity.
Proactivity ã Strive to always be one step ahead.
Loyalty ã Faithful in our long-term partnerships.
Excellence ã The quality of being perfect.
Beside Zeus, Andes, Cromo and Sunda, Long Huei owns other famous brands such asHeros, Imode (Source: Internal information)
COMPANY’S PERFORMANCE
According to Mr Liu, Factory Manager, the company’s revenue growth rate of 2019 is11.3%, net profit growth rate of 2019 is 3.5% and the average output per month of first six months of 2020 is 95083 helmets, of which 30% is for domestic consumption and70% is exported to the world Those are good signals that the company is developing well.
ORGANIZATIONAL STRUCTURE
3.5.2 Function and Responsibility of Each Department
• Manage all activities of the company
• Take responsible for implementing strategies to promote business growth and increase profits These strategies may be about investment plans, business plans, product development plans, branding development plans, etc
• Build and lead a team of senior directors General Director will oversee the operation of this team and provide guidance as needed.
• Manage all planning activities of all departments
• Implement production planning time to time according to the current situation
• Set the production targets and archive on time
• Closely monitor all production activities
• Managing and protecting the information technology
• Managing and protecting the data resource
• Managing and protecting the system applications
• Support business activities with overseas suppliers and customers such as Thailand, Indonesia, Italita, Japan, etc.
There are 8 departments that are Moulding Department, Painting Department, ComfortLining Department, Styrofoam Department, Assembly Department, PrintingDepartment, Resources Department, Procurement Department
Moulding Department: Mold rigid outer shells of helmets, plastic accessories, vents, visor, hat rim, visor rim.
Painting Department: Paint layers on the surface of helmet shells such as colors, polishing oil, decoration decals, etc
Comfort Lining Department: Manufacture comfort liners, chin curtains, ear curtains, straps, fabric bags, etc.
Styrofoam Department: Mold impact absorbing liner
Printing Department: Print logo water slide decals, decorated decals
Assembly Department: Assemble all semi-finished products such as comfort liners, chin curtains, rigid outer shells, impact absorbing liner, visors, etc into a finished helmet
Resource Department: Manage the import and export process of warehouse to ensure the correct schedule; Responsible for all operations at the warehouse; Responsible for inventory control and ensuring inventory accuracy at all times; Manage, inspect and maintain equipment at warehouse
Procurement Department: Collect information of external suppliers, evaluate and select external providers who to achieve the company’s requirements; Implementing purchase goods and services that company need: Continuously inspect and evaluate supplier activities and purchasing activities to maintain the database of the best suppliers to ensure smooth and efficient operations.
• Build, deploy and maintain quality documents of the company
• Responsible for continuous improvement activities to improve quality of products
• Quickly resolve supplier quality errors and take corrective and preventive actions
• Solving and report immediately any product quality problems in production or customer complaint to General Director and follow up any corrective actions and preventive actions of related department
• Report the result of checking and trial run new material sample.
• Combine with R&D committee to check and confirm new product, ensure the new product meet customer requirement.
• Conduct product experiments such as check weight, check appearance, check the size and scope of protection, etc in order to comply to the QCVN 2: 2008/BKHCN.
• Planning strategy, implementation of marketing work, retail market research and competitors.
• Carry out advertising activities (newspaper, internet), organizing public relations, supervise and implement the Company's image-building through image, logo, etc.,
• Identify sales leads in Vietnamese market and turning the opportunities into business
• Develop and meet sales plans that include sales goals and budget,
• Liaise with customers and various internal teams to fulfill projects and sales orders
• Provide professional advice and solutions to address customer needs so as to increase customer satisfaction and loyalty.
• Handle customer inquiries/complaints and respond in a timely and professional manner.
• Provide sales report to management on a regular basis
• Look for new ideas regarding the design, name and material of products in order to carry out a research plan and product deployment according to orientation and strategies of the company
• Be responsible for developing new products, improving products and production technology.
• Manage the company’s cash flow, budget, investments
• Handle all day-to-day transactions of the company
• Provide finance report on a regular basis
• Recruit, screen, interview and hire qualified candidates
• Handle the training and development of staff within an organization
• Handle employee payroll, pensions, insurance
OVERVIEW OF THE PRODUCTS OF LONG HUEI COMPANY
Long Huei company specializes in manufacturing and trading protective helmets for motorcycle and moped users.
Helmets are items for the purpose of protecting the head of the user when there are impacts during cycling, riding motorbikes, cars, or horses, etc.
3.6.2 Main Elements of a Common Helmet
Figure 3 7 Parts of a common helmet
A standard helmet consists of six main parts, including:
Rigid outer shell: deflects and reduces the impact from the outside The company’s shells are made from ABS plastic, PP plastic and PC plastic.
Impact absorbing liner (Styrofoam shell- Research Object): absorbs the energy that your head bangs against the interior of the helmet with during a crash.
Comfort liner: which adds to fit of the lid, enhances moisture wicking and provides a comfortable feel to the face and ears.
Retention system: can withstand strong traction, and help keeping the helmet on the rider’s head.
Face shield (Visor): There are two kinds of visors:
PC visor: it is made of transparent PC plastic can help prevent wind, dust, and objects from getting into users’ eyes, or protect users’ faces
Sun visor: it provides UV protection.
Additional face protection is usually chin protection part
Currently, with the strengths of the modern factories, equipment, long-standing experience of manufacturing helmets and highly skilled workforce, the company has the capacity to completely manufacture main parts of helmets without outsourcing, with the in-house manufacturing rate of 91% (According to Factory manager)
This helps Long Huei Vietnam have more control over its production process quality, because if the company outsource, they cannot keep an eye on the suppliers In addition, the company can not only eliminate the supplier profit upcharge, delivery costs, but also reduce the production cost by purchasing raw materials directly from manufacturers As a result, Long Huei Vietnam can ensure its high quality, and place more reasonable prices for its helmets in order to compete other helmet manufacturers.
First of all, the suppliers supply raw materials such as plastic, EPS material, fabric,paints, glues, etc for the production departments, including Moulding, Printing,Styrofoam, Lining, Painting
Figure 3 8 Production process of a finished helmet
Plastic materials are molded into rigid outer shell, plastic accessories, visor, hat rim, visor rim, duckbills, etc Printing stage is responsible for printing out water slide decals After that, rigid outer shells are painted according to 5 steps:
- Step one: the rigid shell is cleaned and polished
- Step two: the shell is applied a layer of primer before painting to help the paint to stay on the surface.
- Step three: the shell is painted
- Step four: the shell is applied water slide decals
- Step five: the shell is sprayed a layer of polishing oil
EPS materials are molded into impact absorbing liner at Styrofoam stage.
Comfort liner, chin curtain, ear curtain, chin strap, cheek pad, fabric bag, etc are manufactured at Lining stage
Finally, all the semi-finished products are assembled into finished helmets.
3.6.4 The Helmet Type of Long Huei Company
Currently, Long Huei manufactures six types of helmets, including Motocross, Full face, Half face, Modular, Jet and Junior (See detail descriptions of all those helmet kinds in Appendix B).
SUPPLY CHAIN OF LONG HUEI VIETNAM COMPANY
Figure 3 10 Supply chain of Long Huei Vietnam 3.7.1 Supplier
Long Huei Vietnam’s suppliers are mainly Vietnamese and Taiwanese suppliers, supplying materials such as EPS materials, plastic materials, fabric, carton boxes, helmet buttons, etc.
Supplier Manufacturer Distributor Retailer Customer
Long Huei Vietnam manufactures almost all parts of a helmet such as rigid outer shells, impact absorbing liners, comfort liners, visors, vents, etc and assembles finished helmets.
The distributor is responsible for selling the Long Huei’s helmets at Vietnamese market In 2007, Anh Toc Company Limited was chosen by the manufacturer to be the official distributor of Andes Helmets in Vietnam in order to widely distribute Andes products to consumers Towards the rest of Long Huei’ brands, Long Huei Vietnam is responsible for selling the helmets.
The Andes showroom system includes 15 official stores in several districts in Ho Chi Minh City and 1 store in Can Tho and a number of other retailers around Vietnam. Besides, The Sunda brand has currently nearly 600 retailers around Vietnam and one showroom in Hanoi Thanks to a wide distribution network, the Long Huei products can increase the brand awareness and help customers reach the products more easily.
According to Mr Liu Ying Ju, Factory Manager, Andes, Sunda, Cromo brands are for Vietnamese market Zeus, Imode and Heros brands are for global market The company’s target customers are all customer layers They distinguish customer segments based on prices In terms of Andes, the company focus on promoting in the central and southern areas while Sunda is promoted in the northern area in Vietnam
Besides, Long Huei Vietnam produces helmets for business customers to promote their brands or give their customers helmets as presents Long Huei Vietnam design the brand logos and images according to the requirements of business customers There are a number of famous business customers of Long Huei Vietnam are Coca Cola,Lotteria, Vietcombank, Unilever, Vespa, Vinaphone, BIDV etc
Figure 3 11 Promotion helmets for Coca cola business customer
Besides, Long Huei Vietnam also manufactures helmets for business customers according to their requirements Those business customers sell helmets under their own brands such as Bulldog, Yamaha, etc
Figure 3 12 A helmet of Bulldog brand
OVERVIEW OF COMPETITORS OF LONG HUEI VIETNAM IN VIETNAM
According to Mr Liu Ying Ju, Factory Manager, the main competitor of company inVietnam is ASIA brand of A Chau PTE Co., Ltd A Chau PTE Co., Ltd is a helmet manufacturer, was established in 2008 ASIA helmets met the quality standard ofTCVN ISO 9001: 2008 and voted by consumers "kai") meaning change and the word High Quality Vietnamese Goods2013"kai") meaning change and the word Its head office is located in 38 Luong Truc Dam, Hiep Tan ward, Tan Phu district, HCMC and its plant is located at 13/5A Huong Lo 11, Tan Quy Tay, BinhChanh district, HCMC The company owns closed production line, advanced production technology from Japan with the productivity per day of 10.000 products.Although the productivity is not equal to Long Huei Vietnam (Nearly 100.000 products per month), A Chau company equipped modern facilities which can meetVNQC standard bring the best products to customers with competitive prices
Besides, the product range of A Chau company is diversified, including full face, half face, modular, jet helmets Long Huei Vietnam has a larger product range compared to
A Chau company, with kid helmets and motocross.
The logo of A Chau PTE limited company is similar with the Andes brand This might make customers confuse between two brands While Andes brand was established in
2001, Asia helmet was established in 2008
Figure 3 13 Logo of the A Chau PTE limited company
A Chau PTE currently have wide distribution system around Vietnam, collaborating with big supermarkets such as BigC, Coop Mart, Metro, Citimart, Vinatex-Mart, etc It currently owns two showrooms at Hanoi A Chau company has a number of business customers such as VietinBank, Vietcombank, Sacombank, HDbank, Grab, Unilever, etc and the company offer free design fees for its customers
In order to compete strong rivals in market, Long Huei Vietnam must continuously improve its product quality which not only meets the specification but also satisfy customers’ needs.
QUALITY IMPROVEMENT OF STYROFOAM SHELLS BY
BRIEF INTRODUCTION OF STYROFOAM DEPARTMENT
The impact absorbing liner (or called Styrofoam shell) helps soften and absorb the energy that your head bangs against the interior of the helmet with during a crash
Figure 4 1 Impact Absorbing liner (Styrofoam shell)
The material of manufacturing this liner is EPS material (EPS stands for Expanded Polystyrene) which is a high-tech version of the common Styrofoam material with the special attributes such as lightweight, rigid, closed cell insulation
4.1.2 Stages of Manufacturing Styrofoam Shells
The first stage of manufacturing Styrofoam shells is to expand them inside a steam chamber The 200 degrees Celsius heat causes the pentane gas in the pellets to escape allowing air to enter the pellets and inflate them up to 40 times their original size
Figure 4 3 The polystyrene pellets before and after expansion
The factory bags the expanded pellets in huge sacks to make expanded polystyrene helmet shells The workers start by dumping sacks of expanded pellets into the moulding machine It steams fuse the pellets together, moulding them into Styrofoam shells
DMAIC PROCESS
Figure 4 5 DMAIC Process 4.2.1 Define Phase
First of all, as mentioned in the rationale of the study, based on the data of the defect rates in six production departments, the quality problem of Styrofoam department has become more seriously due to its highest defect rate (0.91%); thus, this department is the priority to be the research scale of improvement project.
One of other reasons why the problem at Styrofoam department should be given a priority is that Styrofoam shells are also ones of six important elements of a helmet (rigid outer shell; Styrofoam shell; comfort liner; retention system; face shield and additional face protection), which significantly impacts the product quality and customer satisfaction
Styrofoam shells after being produced and meet quality requirements will be sent to the Assembly department to assemble with other semi-finished products into a complete helmet The cut-through of a standard full-face helmet reveals the main layers: the outer layer (shell), the EPS layer (Styrofoam shell) and the comfort liner. (Figure 4.6)
The EPS layer is mainly used to absorb impact, it is also the connection layer between the outer shell and the comfort liner If the Styrofoam layer has defects, it will affect the structure of a helmet In addition, if there are many Styrofoam-shell defectives, it will cause bottleneck phenomenon, causing the followed assembly processes to wait, causing waste and affecting the time to complete the orders on time.
Figure 4 6 The cut-through of a standard full-face helmet
Due to the Styrofoam department’s highest defect rate and its importance towards the quality of a finished helmet, the Styrofoam department is chosen as the research scale of improvement project.
As it is decided to work and analysis the defects in Styrofoam department, following SIPOC diagram is used to understand the clear relationship between customer and supplier relationship
The acronym SIPOC stands for Suppliers, inputs, process, outputs, and customers:
Suppliers to Styrofoam shell moulding (SSM) process are Raw EPS beads suppliers.
Inputs to SSM process are Man, Machine, Electricity, Expanded EPS beads, Instruction charts, Compressed air, Water, Measuring systems.
Process taking place at SSM process includes two phases: Expansion and Shaping shell.
Output of the SSM process are Styrofoam shells, Production reports, Quality reports.
Customers of the SSM process are Inspection, Repair process, Assembly department.
Using this data, a SIPOC diagram is created:
SUPPLIER INPUT PROCESS OUTPUT CUSTOMER
Expanded EPS beads Instruction charts Compressed air Water
Styrofoam shell moulding process includes two phases:
Figure 4 7 Pareto chart of defect rate of Styrofoam department
From this Analysis, it is clearly seen that Structure defect (78.6%) is the most critical of all rejections (Figure 4.8)
Table 4 2 Project charter Project charter
Name of the project: Defect rate reduction in the Styrofoam department
- Styrofoam department, factory 3, Long Huei (Vietnam) limited company, Kim Huy industrial park, Binh Duong
Problem summary: The quality problem at the Styrofoam department has become more serious because its defect rates was the highest among other production departments In addition, currently there is not any project that has been undertaken with the aim of improving the ratio of the semi-finished product effectively and maintaining the stability of the Styrofoam department, therefore; PM team will be priority for this project
Goal of this project: Define root causes and reduce the Structure defect rate in
Mr Liu (Factory manager) and Ms.Tseng (Quality manager): supervisors, team leaders
Tran Thi Anh Nhu: member, intern, collect and analyse data, brainstorm ideas, propose and implement solution and control plan
Mr Day (Styrofoam production manager): provide insight about the Styrofoam department, Styrofoam manufacturing process, machines
Ms Thuy (QC staff at Styrofoam department): Provide information about defects of Styrofoam shells
Ms Phung (Deputy quality manager): provide QC reports, supervise and support in collecting and analyzing data process
The output of the structure defect is a foam compression testing machine; thus, the author decided to analyse the reliability of the foam compression testing machine.
In order to evaluate the reliability of the machine, compare test results of 100 products, that done 3 times by 3 different workers (Appendix C)
After collecting data, using Minitab software to analyse Analysis results usingMinitab software below:
Figure 4 8 %Contribution analysis result on Minitab
The %Contribution for part-to-part variation is 99.24% (Figure 4.8) When the
%Contribution from part-to-part variation is high, the measurement system can reliably distinguish between parts.
Figure 4 9 %Study Var analysis result on Minitab
According to AIAG guideline, if the measurement system variation is less than 10% of the process variation, then the measurement system is acceptable In this case, the
%Study Var is 8.72% (Figure 4.9) [CITATION Chr10 \l 2057 ]
Table 4 3 Standards for MSA assessment 1
1 Source: Automotive Industry Action Group (AIAG) (2010) Measurement Systems Analysis Reference Manual,4th edition
The measurement system is acceptable 96~100%