Application of six sigma methodology in battery assembly line to improve quality and productivity

I – TITLE: APPLICATION OF SIX SIGMA METHODOLOGY IN BATTERY ASSEMBLY LINE TO IMPROVE QUALITY AND PRODUCTIVITY / NGHIÊN CỨU CẢI TIẾN CHẤT LƯỢNG VÀ NĂNG SUẤT CHUYỀN LẮP RÁP DÒNG SẢN PHẨM P

HO CHI MINH CITY UNIVERSITY OF TECHNOLOGY – VNU HCM

Instructor 1: Assoc Prof PhD Do Ngoc Hien

Instructor 2: Assoc Prof PhD Le Ngoc Quynh Lam

Examiner 1: PhD Nguyen Van Thanh

Examiner 2: PhD Nguyen Duc Duy

Master’s Thesis is defended at HCMC University of Technology, VNU-HCM on January 08, 2023 The Board of The Master’s Thesis Defense Council includes: 1 Chairman: PhD Nguyen Vang Phuc Nguyen

2 Secretary: PhD Duong Quoc Buu

3 Counter-Argument Member: PhD Nguyen Van Thanh

4 Counter-Argument Member: PhD Nguyen Duc Duy

5 Council Member: Assoc Prof PhD Do Ngoc Hien

Verification of the Chairman of the Master’s Thesis Defense Council and the Dean

of the Faculty of Mechanical Engineering after the thesis is corrected (if any)

CHAIRMAN OF THE COUNCIL

(Full name and signature)

DEAN OF FACULTY OF MECHANICAL

ENGINEERING

(Full name and signature)

MASTER’S THESIS ASSIGNMENTS

Full name: Nong Ngoc Vu Learner ID: 2070335 Date of birth: March 03, 1996 Place of birth: Binh Phuoc Major: Industrial Engineering Major ID: 2070335

I – TITLE: APPLICATION OF SIX SIGMA METHODOLOGY IN BATTERY

ASSEMBLY LINE TO IMPROVE QUALITY AND PRODUCTIVITY / NGHIÊN CỨU CẢI TIẾN CHẤT LƯỢNG VÀ NĂNG SUẤT CHUYỀN LẮP RÁP DÒNG SẢN PHẨM PIN VỚI GIẢI PHÁP SIX SIGMA

II – ASSIGNMENTS AND CONTENT:

- Analyze the current state of quality in battery assembly line, identify problems and find the causes

- Analyze the current state of productivity of the line and find the causes

- Deploy 6 Sigma by using DMAIC cycle for battery assembly line

- Record and analyze the results achieved from the Six Sigma methodology

III – ASSIGNMENT DELIVERING DATE: September 05, 2022

IV – ASSIGNMENT COMPLETING DATE: December 18, 2022

V – INSTRUCTOR: Assoc Prof PhD Do Ngoc Hien - Assoc Prof PhD Le Ngoc

(Full name and signature)

DEAN OF FACULTY OF MECHANICAL ENGINEERING

(Full name and signature)

methodology in battery assembly line to improve quality and productivity", I received guidance and support to be able to carry out the thesis Therefore, I would like to express my sincere thanks to:

- Mr Do Ngoc Hien, Department of Industrial Systems Engineering, Faculty

of Mechanical Engineering, Ho Chi Minh City University of Technology

He has guided, advised and supported me throughout the process of making the outline and doing the thesis

- Teachers in the Department of Industrial Systems Engineering, Faculty of Mechanical Engineering, Ho Chi Minh City University of Technology have enthusiastically shared and consult knowledge and suggestions for the topic

- The suggestions and information sharing of the company managers and colleagues in my business, classmates and friends who did the support me

in the process of data collection and implementation of the thesis

Finally, I would like to express deep gratitude to family and friends, classmates, who have always supported and given me strength to complete this thesis

Wishing you and everyone a lot of health, happiness and success in life!

Ho Chi Minh City, December 18, 2022

Nong Ngoc Vu

In the trend of global economic transformation, the pressure is creasing on the companies, factories due to competition Specifically, battery manufactures are struggling on many aspects including competitive production process, effectiveness, quality control… The Techtronic Industries company is one of those, the quality control and the performance of the process have not been at highly optimizing level since the factory were recently established in 2019 The battery product of the company got high customer return ratio of 0.5%, low overall sigma level of 3.95 and the actual production output attainment of 88% with plan There is a need of increasing the quality and productivity

Purpose and solution:

To carrying out and implementing the thesis with the topic of improving the quality and productivity of the battery assembly line with Six Sigma solution by using DMAIC cycle at Techtronic Industries company From the review of various literatures, it is revealed that Six Sigma is well adopted in many manufacturing processes as effective systematic approach The thesis is going is study theories related to Six Sigma, analyze the current status of the battery assembly line, determine the causes affecting quality and productivity failures, plan and implement improvement into the assembly line according to the DMAIC cycle

Results:

- Sigma level of overall production line increased from 3.95σ to 4.12σ

- Production output capacity increased from 76 pcs/h to 81 pcs/h

- Actual production output attainment of plan increased from 88% to 96%

Practical meaning:

Reduce the failures of the production line and improve the productivity of the line Play as a basis reference for the deployment to other lines in the company The thesis is an application of Six Sigma solution to battery assembly process

Mô tả vấn đề:

Trong xu thế chuyển đổi kinh tế toàn cầu, áp lực cạnh tranh ngày càng lớn đối với các công ty, nhà máy Cụ thể, các nhà sản xuất pin đang gặp khó khăn về nhiều mặt bao gồm tối ưu quy trình sản xuất, hiệu quả sản xuất, kiểm soát chất lượng… Công ty Techtronic Industries là một trong số đó, việc kiểm soát chất lượng và hiệu suất của quy trình chưa được tối ưu hóa cao do nhà máy mới được thành lập Sản phẩm pin của công ty có tỷ lệ lỗi phản hồi từ khách hàng cao là 0,5%, mức sigma chung là 3,95 và sản lượng sản xuất thực tế đạt 88% so với kế hoạch Nâng cao chất lượng và năng suất trên dây chuyền mang tính cấp thiết cao

Mục đích và giải pháp:

Tác giả mong muốn triển khai và thực hiện luận văn với chủ đề nâng cao chất lượng và năng suất của dây chuyền lắp ráp pin bằng giải pháp Six Sigma theo chu trình DMAIC tại công ty Techtronic Industries Từ việc xem xét các tài liệu khác nhau cho thấy Six Sigma được áp dụng tốt trong nhiều quy trình sản xuất và đóng vài trò như một phương pháp tiếp cận có hệ thống và hiệu quả Luận văn tiến hành nghiên cứu các lý thuyết liên quan đến Six Sigma, phân tích hiện trạng dây chuyền lắp ráp pin, xác định nguyên nhân ảnh hưởng đến chất lượng và năng suất, lập kế hoạch và thực hiện cải tiến dây chuyền lắp ráp theo chu trình DMAIC

Kết quả:

- Mức sigma của dây chuyền sản xuất tăng từ 3.95σ lên đến 4.12σ

- Năng lực sản xuất của dây chuyền tăng từ 76 lên 81 sản phẩm/giờ

- Tỉ lệ đáp ứng kế hoạch sản xuất tăng từ 88% lên 96%

Ý nghĩa thực tiễn:

Giảm tỉ lệ lỗi của dây chuyền sản xuất và nâng cao năng suất của dây chuyền Làm cơ sở tham chiếu cho việc triển khai đến các dây chuyền khác trong công ty Luận văn là một ví dụ ứng dụng giải pháp Six Sigma vào quá trình lắp ráp pin trong doanh nghiệp

methodology in battery assembly line to improve quality and productivity” was

carried out by myself and the work contained and the results in it are true by author

and have not violated research ethics The data and figures presented in this thesis are

for analysis, comments, and evaluations from various resources by my own work and

have been duly acknowledged in the reference part

I will take full responsibility for any fraud detected in my thesis

MASTER’S THESIS ASSIGNMENTS ii

ACKNOWLEDGEMET iii

ABSTRACT iv

TÓM TẮT LUẬN VĂN v

DECLARATION OF AUTHORSHIP vi

TABLE OF CONTENTS vii

LIST OF FIGURES x

LIST OF TABLES xiii

LIST OF ABBREVIATIONS xiv

CHAPTER 1: INTRODUCTION 1

1.1 Problem statement 1

1.2 Research objectives 3

1.3 Thesis objectives 3

1.4 Thesis structure 3

CHAPTER 2: THEORETICAL BASIS AND LITERATURE REIVEW 5

2.1 Definition 5

2.1.1 Six Sigma 5

2.1.2 Benefits of Six Sigma method 5

2.1.3 DMAIC cycle 5

2.1.4 Sigma level calculation 7

2.1.5 Quality management tools 8

2.1.6 Line balancing by Takt time 12

2.3.1 General methodology 14

2.3.2 Detailed methodology 14

CHAPTER 3: DEFINE PHASE 16

3.1 About TTI company 16

3.1.1 Introduction 16

3.1.2 Mission, value, quality 16

3.1.3 Products 18

3.1.4 Battery product and production 18

3.1.5 Battery assembly process 22

3.1.6 SIPOC chart 28

3.1.7 Define phase 28

CHAPTER 4: IMPLEMENT SIX SIGMA DMAIC 35

4.1 Measure 35

4.2 Analyze 36

4.2.1 Welding Failure 37

4.2.2 Pack Voltage Fail 40

4.2.3 Gap between demand and actual output 43

4.3 Improve 44

4.3.1 Improvement plan 44

4.3.2 Improvement deployment-Quality 47

4.3.3 Improvement deployment- Productivity 65

4.3.4 Improvement Assessment 68

4.4.2 Check sheet 72

4.4.3 Solutions are documented 73

CHAPTER 5: CONCLUSION AND SUGGESTION 74

5.1 Conclusion and discussion 74

5.2 Suggestion 74

REFERENCES 75

CURICULUM VITAE 77

EDUCATION PROCESS: 77

WORKING HISTORY: 77

Figure 2.2: Fishbone diagram 8

Figure 2.3: Pareto chart 9

Figure 2.4: Histogram chart 10

Figure 2.5: Scatter chart 11

Figure 2.6: General methodology 14

Figure 2.7: Detailed methodology 15

Figure 3.1: Some products of the company 18

Figure 3.2: Batteries and battery families 19

Figure 3.3: Battery production layout 21

Figure 3.4: Cell sorting 22

Figure 3.5: Assemble the cell into carrier 22

Figure 3.7: Attach the metal pieces and put them into the automatic welding machine 23

Figure 3.7: Welding machine 23

Figure 3.8: Install the PCBA to the cells 24

Figure 3.9: Automatic soldering machine 24

Figure 3.10: Laser engraving 25

Figure 3.11: Performance test 25

Figure 3.12: Attach foams and gasket seal 26

Figure 3.13: Function test 26

Figure 3.14: Labels 27

Figure 3.15: SIPOC 28

Figure 3.18: Quality check 30

Figure 3.19: Demand vs actual output 32

Figure 4.1: Internal DPMO (May-July 2022) 35

Figure 4.2: Pareto of top defects 36

Figure 4.3: Welding failure 37

Figure 4.4: Fishbone diagram for welding failures 37

Figure 4.5: Fishbone with highlighted causes 39

Figure 4.6: Fishbone diagram for pack voltage fail 41

Figure 4.7: Highlighted causes for pack voltage fail 43

Figure 4.8: Fishbone diagram for gap between demand and actual output 44

Figure 4.9: Doing Gemba to improve alignment 48

Figure 4.10: Set up automatic grinding for welding tip 49

Figure 4.11: Terms with p value 52

Figure 4.12: Terms after removing insignificantly terms 52

Figure 4.13: Best regression equation 53

Figure 4.14: Adjusted R-square 53

Figure 4.15: VIF value 54

Figure 4.16: Residual plots 55

Figure 4.17: Main effects plot 55

Figure 4.18: Optimal plot 56

Figure 4.19: Standardize the cleaning process for soldering cleaning 57

Figure 4.20: Set up grooving mechanism 58

Figure 4.23: Check solder tips every shift 61

Figure 4.24: Histogram for 2 suppliers 62

Figure 4.25: Process Capability for Lishen supplier at sorting station 62

Figure 4.26: Process Capability for High Star supplier at sorting station 63

Figure 4.27: Process Capability for pack voltage at function test by using Lishen cell 64

Figure 4.28: Process capability for pack voltage at function test by using Highstar cell 64

Figure 4.29: Improve fixture at labeling station 65

Figure 4.30: Improve the scanning process 66

Figure 4.31: Redistribute task between stations 67

Figure 4.32: DPMO after improvement 69

Figure 4.33: Control chart assessment 70

Figure 4.34: Productivity improvement 71

Figure 4.35: Attainment of the plan 71

Figure 4.36: Control chart to be monitored 72

Table 3.1: Battery assembly process 20

Table 3.2: Type of defects 31

Table 3.3: VOC table 33

Table 3.4: Project charter 34

Table 4.1: Tools for analyzing 36

Table 4.2: Eliminate some causes 38

Table 4.3: 5 why technique for welding failure 38

Table 4.4: Eliminate causes for pack voltage fail 41

Table 4.5: 5 why technique for pack voltage failure 42

Table 4.6: Explanations for eliminating causes of gap 43

Table 4.7: Improvement plan 45

Table 4.8: Priority for improvement actions 46

Table 4.9: Easiness ranking 47

Table 4.10: Cost ranking 47

Table 4.11: DOE design 49

Table 4.12: DOE treatment 50

Table 4.13: Run DOE 51

Table 4.14: Optimum value 57

Table 4.15: Solder balls improvement 59

Table 4.16: Completion date for actions 68

Table 4.17: Sigma level improvement 69

Table 4.18: Check sheet 73

Abbreviation Meaning

CHAPTER 1: INTRODUCTION 1.1 Problem statement

With the trend of shifting to renewable energy and reducing dependence on fossil energy, energy and charge storage is very interested and increasingly booming Mobile sectors especially electric vehicles will drive the demand for batteries, with Lithium-Ion batteries dominating the future market share Demand for batteries is forecast to grow rapidly by up to 25% per year, and hundreds of plants will be built

to meet demand by 2030 (Jacky, 2022)

Research and Market has published its global battery market report for

2020-2027 in 2021 According to this report, in the context of Covid-19, the global battery market is still quietly growing, reaching 120.4 billion in 2020, expected to increase

to 279.7 billion USD in 2027, a compound annual growth of 12.8% in the period 2020-2027 The US market is estimated at $ 32.5 billion and China is estimated at $ 61.1 billion by 2027, other markets such as Japan and Canada are forecast to grow by 9% and 11.1%, respectively [1]

The battery industry in our country is currently on the rise because most devices and explosive machines need to use battery systems And batteries are one of the products with a long lifespan and today battery products are increasing Batteries are also a key part of the electric vehicle industry and are considered the "next generation growth engine" On the other hand, the price of raw materials (lithium, cobalt) is on

a downward trend, contributing to the reduction of production costs Thus, the battery manufacturing industry has great potential to promote development

Of course, the fast pace of development also comes with strict competition Battery manufacturers are struggling on many aspects including sustainability; stable and competitive production process; safety; effectiveness

In the trend of global economic transformation, the pressure is increasing on companies, factories and enterprises due to competition and constant change In which, TTI (Techtronic Industries) is also a battery manufacturer in Vietnam that is

influenced by competition and constant changes in the battery industry And in order

to improve competitiveness and respond to continuous development, TTI company

as well as many businesses are always interested in the important factors such as production cost, product quality, and delivery time The goal of manufacturers is always to reduce the cost of creating products but still meet the expectations of customers, in parallel revenue and profit will be optimized

The problems in production that TTI enterprises, where students are working, can be mentioned as follows and will be described in chapter 3

- Poor quality problems, high fail rate in the production line, high return rate greater than 0.5%

- The problem of productivity and output, which does not meet the

production demand Productivity meets only 88% of demands

- Waste in production, low performance

With the problems encountered in production, it is necessary to use solutions to overcome and improve the current situation Six Sigma is frequently used to approach and solve problems in manufacturing

Six Sigma is a system of process improvement methods to minimize failure, causes of failure, and variation in the process Thereby improving customer satisfaction, increasing market dominance and corporate profits and many other benefits Although Six Sigma is an approach to improving quality and processes commonly used in manufacturing, it is now also used in many other sectors such as banking, hospitals, financial services, aviation, utility services and many others [2] [3]

From the benefits of applying 6 Sigma to manufacturing activities to improving quality and improving product productivity and urgency from the difficulties of the

business, the topic: " Application of Six Sigma Methodology in Battery Assembly Line to Improve Quality and Productivity " was carried out

1.2 Research objectives

The study uses a Six Sigma method to approach battery assembly lines to improve quality and productivity

1.3 Thesis objectives

- Analyze the current state of quality in battery assembly line, identify

problems and find the causes

- Analyze the current state of productivity of the line and find the causes

- Deploy 6 Sigma by using DMAIC cycle for battery assembly line

- Record and analyze the results achieved from the Six Sigma methodology

1.4 Thesis structure

The content of the dissertation consists of 5 chapters, specifically as follows:

- Chapter 1: Overview

➢ Identify research issues and objectives

➢ Content and scope of research

- Chapter 2: Theoretical and Methodological Foundations

➢ Theoretical basis

➢ Related studies

➢ General methodology

➢ Specific methodology

- Chapter 3: Analyzing the Current Situation

➢ Analyze the status and identify problems

➢ Identify the cause

- Chapter 4: Six Sigma Implementation

➢ Follow the DMAIC cycle

➢ Line balance assessment

CHAPTER 2: THEORETICAL BASIS AND LITERATURE REIVEW 2.1 Definition

2.1.1 Six Sigma

The International Organization for Standardization (ISO) defines, "6 Sigma is a

statistically based business improvement approach that seeks to find and eliminate defects and their causes from an organization's processes, focusing on outputs that matter to customers."

2.1.2 Benefits of Six Sigma method

- Reduce production costs

- Reduce management costs

- Increase customer satisfaction

- Reduce cycle time

- Help businesses deliver goods on time

- 6 Sigma makes it easy for businesses to expand production

2.1.3 DMAIC cycle

Six Sigma is a well-structured improvement method, which is an improvement method characterized by a 5-stage DMAIC process such as Figure 2.1

a D – Define

As the first stage of the DMAIC cycle, the "Define" Phase consists of the

Figure 2.1: DMAIC cycle

- Identify customers (internal, external) and find out the voice of customers

to find products, services, processes with Critical to Quality characteristics (CTQ)

- Set up a SIPOC chart with information about the process's suppliers,

inputs, processes, outputs, and customers

- Clarify each process item in the overall process

The goal of the "Define" phase is to present the problem to be solved, the scope and objectives of the project

b M – Measure

This stage will measure the current performance of the process, detecting the factors that affect the process The goal of the "Measurement" phase is to quantify and understand the current state of the problem The "measurement" phase includes:

- Identify specific performance requirements related to CTQ characteristics

- Create process maps related to defined inputs and outputs Each step of the process must show the relationship between input to output

- Set a comparative milestone in terms of process capacity

- Identify areas where failure during measurement may occur of the process

- Conduct measurement and data collection of input, middle and output agents of the process

c A – Analyze

This "Analyze" phase will analyze the data that has been collected in the previous phase to identify the potential root causes of the problem Several tools are used to identify the root cause and effect on the problem, such as Pareto charts, cause-and-effect charts, "5 why" methods, FMEA etc The outputs of this stage demonstrate the root causes are more likely to affect the process

d I – Improve

The improvement phase includes innovative improvement and selection of optimal or near-optimal solutions for the best results and the most powerful

efficiency There are many tools used for the improvement process Four steps are required to carry out the improvement phase

- Initialize improvement plans

- Evaluation and selection of solutions

to assess the capabilities of the process over time

2.1.4 Sigma level calculation

The sigma level is used to indicate defects per million opportunities, the purpose

of six sigma is to aim for a minimum of defective products If process reach 6 sigma,

it means that there are only 3.4 defects per million chances of a defect The higher the sigma level, the less defects that equate to the cost of production, higher profitability, higher quality

The DPMO estimation is used for evaluating the process performance measured

in terms of attribute data such as nonconforming units or defective or defects, especially when there are multi processes with complexity of data such as continuous, attribute data in the overall process

DPMO calculation formula (Defects per million opportunity) as shown in equation 2.1

From the DPMO index, it is possible to rely on the following Table 2.1 to convert to sigma level or process yield performance It is noted that the sigma level when retrieve in short term will be shift 1.5σ in long term [4] An example is that if the sigma level of process is 6σ in short term, it could be only 4.5σ in long term

2.1.5 Quality management tools

a Fishbone diagram

Fishbone diagram, also known as ISHIKAWA chart The chart is used to examine cause-and-effect relationships or analyze causes and problems and are a popular tool for improvement projects At the same time, it is also an approach and

Figure 2.2: Fishbone diagram

set of opinions (Brainstorming), input parameter values in the multiple regression or experimental design with x – variable or parameter and y – result variable

To construct a chart as shown in Figure 2.2, the following steps should be performed:

- Step 1: Identify the problem/consequences

- Step 2: Create an analysis team

- Step 3: Draw the consequence box and centerline

- Step 4: Identify the main causes

- Step 5: Identify and classify possible causes

- Step 6: Rank the causes according to the order of causes that affect the most

b Pareto chart

Pareto charts are used to show how often defects occur, used to prioritize problems that need to be addressed Focusing on addressing the most frequently occurring failure will result in the greatest improvement in results To build a Pareto chart as shown in Figure 2.3, the following steps should be performed:

Figure 2.3: Pareto chart

- Step 1: Distribute data attributes sorted by type

- Step 2: Sort in descending frequency order from left to right

- Step 3: Help detect the most common failure

- Step 4: Distinguish the most common error from the most important one

c Histogram

Histogram charts are used to measure the frequency of a certain problem, clearly showing the change and fluctuation of a data set Example on the image Figure 2.4 in terms of product diameter dimensions

The principle of quality control is to capture the causes of quality fluctuations and to manage those factors For this purpose, it is necessary to know the fluctuation (distribution) of specific data properly Through the layout of the data on a distribution chart, we can understand the whole objectively

The purpose of setting up a distribution chart is to:

- Knowing the distribution shape in the form of a graph makes it easier to understand

Figure 2.4: Histogram chart

- Know the process capacity compared to standards (technical regulations)

- Analyze the process and manage it

- Know the center and fluctuations of distribution

And from the above information the user can:

- Spot problems and set up improvement programs

- Consider which actions are effective

- Affirmation of the results of actions

d Scatter Diagram

A scatter chart is used to determine whether there is a regular dispersion trend

in the position of points

To draw a scatter chart as shown on Figure 2.5 needs:

1 Collect data that needs to be found (at least 30 data)

- Select data for the horizontal and vertical axes, write the ratio of the axes: When the 2 axes have a causal relationship, the horizontal axis is the cause and the vertical axis is the result Represent the data pair on the chart with

a dot: if there is the same or duplicate data, mark "O" at that point

- Fill in the topic: what problem survey, survey date, number of samples, creator, how to collect data

People use scatter charts to:

Figure 2.5: Scatter chart

- A scatter chart is used to determine whether a correlation exists between two characteristics by marking pairs of figures on the X-Y coordinate system or marking 1 characteristic on the Y axis and other characteristics

on the X-axis

- Determine the level of correlation based on a scatter chart

- Based on scatter chart analysis, r-factor and regression equation, quality characteristics and process characteristics can be predicted, as well as identify factors that need to be strictly controlled to ensure product quality

2.1.6 Line balancing by Takt time

- Minimize the number of workstations

- Maximum efficiency of resource use

- Minimum production cycle

- Minimum waiting time between stages

2.2 Related research

There is a lot of research on the application of six sigma solutions in improving production quality in particular and improving processes in general Some of the research related to the topic being carried out is mentioned as follows

Nataraj and Ismail carried out quality improvement research at the wheel shell factory By implementing the six sigma DMAIC solution using tools such as herringbone charts, Pareto, process charts, frequency charts The researchers reduced the error rate, specifically from 95.9% to 97% [5]

Desai et al applied DMAIC to a ceramic manufacturing company that reduced the error rate from 0.5% to 0.1% and the sigma level increased from 4.4 to 5.0 [6] Marques and Matthé conducted research at an aluminum foundry in Portugal, using their Six Sigma DMAIC solution, which increased sigma levels from 2.3 to 3.1 and error rates from 79% to 25% [7]

In Vietnam, there are also related studies Tran Le Duy improved the quality of audio equipment assembly lines according to the DMAIC process, increasing the yield rate by 0.5% to 95.3% [8] [9]

Thus, from previous studies, six sigma DMAIC solution is a very effective solution in improving the quality of production processes Research on applying six sigma solutions to businesses is relatively small battery assembly process Therefore, the implementation of the project of applying six sigma solutions in the battery manufacturing industry will contribute richly to applied research topics and at the same time solve quality and productivity problems at enterprises

Figure 2.6: General methodology

Figure 2.7: Detailed methodology

CHAPTER 3: DEFINE PHASE 3.1 About TTI company

3.1.1 Introduction

Name: Techtronic Industries Vietnam Manufacturing Co., Ltd

Location: 9A VSIP II-A, Street 27, Vietnam – Singapore Industrial Park II-A, Vinh

Tan Commune, Tan Uyen Town, Binh Duong Province, Vietnam

Techtronic Industries is a leading global company with rapid growth in the field

of power tools, accessories, hand tools, outdoor electrical equipment, self-care vehicle floor (DIY), specialized equipment for consumers and industry in the renovation and repair industry, maintenance, construction of houses and infrastructure The company is committed to accelerating the pace of industry transformation through eco-friendly wireless superior technology TTI's brands such

as MILWAUKEE, RYOBI and HOOVER are recognized worldwide for their longstanding heritages of wireless product foundations with outstanding quality, optimal performance, absolute safety, high productivity and absolutely convincing innovation

3.1.2 Mission, value, quality

a Mission

TTI is a global leader in wireless technology including Machine Tools, Outdoor Electrical Equipment, Floor Care Home Appliances and Spare Parts for consumers, professional users and people working in the household, construction, maintenance, industrial and infrastructure development industries With the goal of implementing innovation throughout the company, we have achieved a leading position in the field

of wireless technology with all kinds of products that are changing the way we work

in these industries

b Core value

Value is the foundation for us to make all decisions and a guideline for all interactions inside and outside the company We strive to ensure that values are enforced at every level of the organization, helping to create trusted relationships and long-term brand loyalty

Core beliefs:

- Do the right thing

- Treat each other with integrity and respect

- Build strong, trusting relationships

- Restore

- The spirit of encouraging innovation

- Exceed customer expectations

c Quality

From the very first day of establishment, Outstanding Quality has been the focus

of TTI It is important for TTI's employees to understand how the company approaches quality holistically; Understanding quality delves into every element that constitutes our organization, from the design phase to product manufacturing, from the hiring process to ongoing leadership development training, and from the supply chain implementation phase to daily interactions with consumers and professionals Quality is the DNA of TTI culture

3.1.3 Products

TTI's products are diverse including handheld products such as chainsaws, blowers, lawn mowers, drills, in addition to providing products such as batteries and charging accessories, etc The Figure 3.1 below provides pictures of products manufactured at the lines at TTI company

3.1.4 Battery product and production

As shown in the previous section, TTI's products are very diverse from outdoor products to indoor products And the special feature is that these products mostly need battery power sources for the product to work Figure 3.2 shows the connection between the products at the enterprise and the battery product The battery product line of the enterprise is a product line that accounts for a large output and is a complementary product to other products Play an important role in the production of the company

Figure 3.1: Some products of the company

The manufacturing process of battery products is described in Table 3.1 There are several stations in the battery line with the corresponding number of operators to

do the tasks The flow of production is going directly from each station to each station

in the line except sub station No.4 is different There are totally 9 stations in the battery assembly process and 14 worker including the material feeder

Figure 3.2: Batteries and battery families

Sub Main Sub Phụ Chính Phụ

Functional testing Kiểm tra chức năng

Paste label into housing Dán tem vào thân pin

Paste label, packing battery into box

Kiểm tra ngoại quan, Dán tem và Đóng gói

Print code on battery cover and material handler

Khắc code cho vỏ pin và cấp nguyên vật liệu

Tin bead inspection; performance

Stick foam; put in the battery cover Dán xốp, lắp cụm pin vào vỏ

Balance test; battery installation;

cover battery holder

Kiểm tra cân bằng/Lắp pin vào khung

Install the connecting piece; install the battery to the welding fixture Lắp miếng kết nối/Hàn tự động

Welding point inspection; assemble

Flow / Dòng chảy Quy trình

số

S.lg công nhân

The dimension of line is not so big with the size of 8.6 meters length and 4 meters width The detail of layout can be referred in the in Figure 3.3 The layout follows U shape of process

Figure 3.3: Battery production layout

3.1.5 Battery assembly process

a Station 1: Sorting

The batteries will be fed into the machine for inspection as shown in Figure 3.4 The output is batteries with an internal voltage and resistance level that is within the standard The good batteries from the machine will be assembled into battery-free trays as shown in Figure 3.5 then locked 4 screws

b Station 2: Assemble the strap and operate the welding machine

The battery assembly will be fitted with nickel metal pieces on both sides such

as Figure 3.7 and assembled into jigs to be put into the automatic welding machine Figure 3.7 The automatic welding machine with a high current of 3.5KA in about some milisecond will tightly weld the metal piece and the battery to create a bond for the battery assembly and connecting pieces

Figure 3.4: Cell sorting

Figure 3.5: Assemble the cell into carrier

Figure 3.7: Attach the metal pieces and put them into the automatic welding

machine

Figure 3.7: Welding machine

c Station 3: Welding check and install PCBA

The battery assembly after welding from the automatic welding machine will

be checked for weld quality, then attach the PCBA and continue to put into the automatic lead welding machine as shown in Figure 3.8 and Figure 3.9

Figure 3.8: Install the PCBA to the cells

Figure 3.9: Automatic soldering machine

d Station 4: Laser engraving

At this station, the battery case is engraved with the characteristic characters of the product from another machine as Figure 3.10 And at the same time workers at this station will supply materials to all stations in the line

e Station 5: Performance test

After soldeing station Solder joints will be inspected by workers and remove solder balls The battery assembly will then be fed into the performance tester on Figure 3.11 The purpose is to test the performance of the battery assemblies, the performance of the PCBA and the voltage and resistance standards of the battery block after welding

Figure 3.10: Laser engraving

Figure 3.11: Performance test