Manufacturing System Lean Manufacturing

MANUFACTURING
SYSTEM

(LEAN MANUFACTURING)

ZURINA AHMAD
MOHD FIRDAUS IBRAHIM

JABATAN KEJURUTERAAN MEKANIKAL
POLITEKNIK SEBERANG PERAI

MANUFACTURING
SYSTEM

(LEAN MANUFACTURING)

Zurina Ahmad
Mohd Firdaus Ibrahim

2022
MECHANICAL ENGINEERING DEPARTMENT

©All rights reserved for electronic, mechanical, recording, or otherwise, without prior permission
in writing from Politeknik Seberang Perai.

ii eBook PSP | 2022

All rights reserved

No part of this publication may be translated or reproduced in any retrieval system or transmitted
in any form or by any means, electronic, mechanical, recording, or otherwise, without prior
permission in writing from Politeknik Seberang Perai.

Published by

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Pulau Pinang

Editor
Ruhil Naznin Azaman

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Norbahiah Zakaria
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Email : [email protected] Website : www.psp.edu.my
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Perpustakaan Negara Malaysia Cataloguing-in-Publication Data

Zurina Ahmad, 1976-
MANUFACTURING SYSTEM : (LEAN MANUFACTURING) / ZURINA AHMAD, MOHD FIRDAUS

IBRAHIM ; Editor Ruhil Naznin Azaman.
Mode of Access: Internet
eISBN 978-967-2774-24-2

1. Lean manufacturing.

2. Manufacturing processes.
3. Government publications--Malaysia.

4. Electronic books.
I. Mohd. Firdaus Ibrahim. II. Ruhil Naznin Azaman.

III. Title.
658.5

eBook PSP | 2022 iii

Acknowledgment

Very thankful to Allah SWT for completing the academic writing for the production of an eBook for
students to learn this course. We would like to express our deepest appreciation to all those who
provided us with the possibility to complete this book. Special gratitude to our head of
department, Mr. Muhammad Nasir Bin Marzuki, whose contribution in stimulating suggestions
and encouragement, helped us to coordinate this work, especially in writing this book. Credit to
Ms. Ruhil Naznin as CTTL coordinator because of her contribution in providing a lot of guidance
and incentives during completing this eBook.

Furthermore, we would also like to acknowledge with much appreciation the crucial role of the
staff of the Mechanical Engineering Department who permitted to use of all required equipment
and the necessary material to complete the task. A special thanks go to our teammate, who help
us to assemble the notes and gave suggestions about the idea in this book. Last but not least,
many thanks go to the director of Politeknik Seberang Perai, Sr. Harith Fadzilah Bin Abd Khalid
whose have invested his full effort in guiding the team in achieving the goal.

Zurina Ahmad
Mohd Firdaus Ibrahim

iv eBook PSP | 2022

Preface

MANUFACTURING SYSTEM in the chapter on Lean provides knowledge about the basic principles
and concepts of lean management in manufacturing systems for delivering value and optimizing
workflows. Learn and understand what the Lean methodology and its benefits are. Reading this
book is one good way to get an understanding of what lean is all about and to get a few ideas for
implementation in real situations.
In chapter 1 of this book, students will get to know the history of lean, be introduced to lean
manufacturing, and the benefits of lean. In chapter 2, students will learn the process
consideration in the lean system, and in chapter 3, students will get to know the continuous
improvement process using the lean system approach. In summary, students will enhance their
knowledge of lean management in a manufacturing system. Thus, will prepare the students to be
in good leadership either in the polytechnic or in the working environment. This module is a
specialized design for manufacturing students.
Upon completion of this chapter, students should be able to attain the concept and application of
the lean system in the manufacturing process. They should also be able to integrate continuous
improvement processes using a lean approach.

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Table of Content

01 LEAN MANUFACTURING 1

1.1 History of Lean 1122
1.2 Introduction to Lean Manufacturing
1.3 Lean Principles Provide a Framework 5
1.4 Create Value, Eliminate Waste 6
1.5 Lean Rules Create a System 7
1.6 Benefits of Lean Manufacturing 9
10
02 PROCESS CONSIDERATIONS IN LEAN SYSTEMS
11
2.1 Pull Method of Workflow
2.2 Quality at The Source 11212

2.3 Uniform Workstation Loads 13
2.4 Standardized Components and Work Methods 16
17
2.5 Flexible Workforce 17
2.6 Automation 18
18
2.7 Five S (5S) Practices 21
2.8 Total Preventive Maintenance (TPM) 21
22
2.9 Small Lot Sizes 22
2.10 Close Supplier Ties
24
2.11 Line Flow
25
03 CONTINUOUS IMPROVEMENT USING LEAN 26
SYSTEM 29
24 35
3.1 Kaizen
3.2 Kanban System 40
3.3 Value Stream Mapping
3.4 Just in Time 42

CASE STUDY 1 44
CASE STUDY 2

REFERENCES



eBook PSP | Manufacturing System 1

01

LEAN
MANUFACTURING

This topic covers the introduction to Lean Manufacturing. It consists of the history of lean, the
introduction to lean manufacturing, lean principles providing a framework, creating value,
eliminating waste, lean rules creating a system, and the benefits of lean manufacturing.

2 eBook PSP | Lean Manufacturing

1.1 History of Lean

Image source: https://ingenium.edu.pe/calidad/lean-manufacturing/
Lean is the concept of efficient manufacturing/operations that grew out of the Toyota
Production System in the middle of the 20th century. It is based on the philosophy of
defining value from the customer’s viewpoint, and continually improving the way value is
delivered, by eliminating every use of resources that is wasteful or does not contribute to
the value goal. Lean is centered on preserving value with less work; with the ultimate
goal of providing perfect value to the customer through a perfect value creation process
that has zero waste. This is done by empowering every individual worker to achieve his or
her full potential, and so to make the greatest possible contribution.
The goal of empowerment is based on the idea of showing respect for people. Respect
for people extends beyond just the end customer and can include the workers, suppliers,
and society. For the end customer, Lean strives to maximize value delivery while
minimizing waste in the process. Lean aims to maximize human potential by empowering
workers to continuously improve their work. Lean leaders facilitate this goal through
problem-solving training. They help workers grow professionally and personally, allowing
them to take pride in their work.

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At the heart of the Lean philosophy is the concept of “kaizen” or continuous
improvement. The goal of continuous improvement is to eliminate all waste in the value
delivery process. To do this, Lean leaders must go where value is created – commonly
known as the Gemba. At Gemba, they often spend their time coaching and developing
their people. They encourage workers to actively identify problems and look for
opportunities for improvement.

To understand the history of Lean, we must go back to the start of modern
manufacturing. Henry Ford was the first to truly integrate a production system called
‘mass production, which manufactures large quantities of standardized products. Ford
created what he called a flow production, which involves the continuous movement of
elements through the production process. Ford used mass production to fabricate and
assemble the components of his vehicles within a few minutes rather than hours or days.
Unlike craft production, the mass production system delivered perfectly fitted
components that are interchangeable. This process was very successful and allowed the
Ford Motor Company to produce over 15 million Model T cars between 1908 and 1927.
During World War II, the US military adopted Ford’s mass production system.
In 1926, Sakichi Toyoda founded the Toyoda Automatic Loom Works. Several years later,
the company changed its name to Toyota when it began producing automobiles. In 1950,
Eiji Toyoda, the nephew of Sakichi, participated in a three-month visit to the Rouge plant
of Ford in Dearborn, Michigan. At the time, the Dearborn facility was Ford’s most complex
and largest manufacturing facility. It produced nearly 8000 cars per day while Toyota
only produced 2500 cars each year.

After studying Ford’s production system, Eiji Toyoda understood that the mass production
system employed by Ford cannot be used by Toyota. The Japanese market was too small
and diverse for mass production. The customer’s requirements ranged from compact
cars to the most luxurious vehicles. Ford’s mass-production system focused on the
amount of production instead of the customer’s voice. Toyota collaborated with Taiichi
Ohno to develop a new means of production. They concluded that through right-sizing
machines for the required volume and introducing self-monitoring machines, they can
make products faster, lower in cost, higher in quality, and most importantly higher in
variety. Ohno faced the challenge of trading between productivity and quality. His

4 eBook PSP | Lean Manufacturing

experiments led to the development of several novel ideas that became known as the
‘Toyota Production System’ (Figure 1.1).
The Toyota Production System (TPS) was established based on two concepts: The first is
called "Jidoka" (which can loosely be translated as "automation with a human touch")
which means that when a problem occurs, the equipment stops immediately, preventing
defective products from being produced. The second is the concept of "Just-in-Time," in
which each process produces only what is needed by the next process in a continuous
flow.
With Jidoka, the equipment stops when a problem arises. This allows a single worker to
visually monitor and efficiently control many machines. As problems arose, the workers
must solve them right away otherwise the whole production line stops. This brings
problems to the surface and promotes identifying and resolving problems at their root
causes.
The idea behind “Just-in-Time” is simple - make only “what is needed, when it is needed,
and in the amount needed”. Using Just-in-Time, Toyota can produce high-quality products
efficiently through the elimination of waste. Based on the basic philosophies of Jidoka
and Just-in-Time, the TPS can efficiently and quickly produce products of sound quality,
one at a time, that fully satisfy customer requirements.

Figure 1.1 The Toyota Production System “House”

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Image source: https://theleanway.net/what-is-lean

1.2 Introduction to Lean Manufacturing

Lean manufacturing, also called lean production, was created in Toyota after the Second
World War in the reconstruction period. It is based on the idea of eliminating any waste in
the industry, i.e., any activity or task that does not add value and requires resources. It is
considered at any level of the industry such as design, manufacturing, distribution, and
customer service. The main wastes are as follows:

Overproduction against the plan
Waiting time of operators and machines
Unnecessary transportation
Waste in the process itself
Excess stock of material and components
Non-value-adding motion
Defects in quality

The wastes eliminated should improve the improvement of quality and the reduction of
the cost and time in manufacturing. Among the main tools used by lean practitioners, but
not limited to, are as following:

Five S. seiri (sort), seiton (set in order), seisō (shine), seiketsu (standardize), and
shitsuke (sustain).
Line flow. The manufacturing is performed sequentially for multiple processes,
contributing to the flow of materials.
Value stream mapping. The tool compares the current state and future state of the
events that depend on the product to reduce waste. It is focused on the areas that
incorporate value to the product.
Kanban (pull systems). The lead time and cycle time are measured in several areas
of the production to detect any problem and avoid it, e.g., to establish an upper limit
to work in process inventory to avoid overcapacity.
Heijunka. The mixed model processing.
Total productive maintenance. The production system is considered as a whole, and
maintenance is focused on that. It leads to the integrity of the maintainability, safety,
quality of the assets, and human resources that add value to the production system.

6 eBook PSP | Lean Manufacturing

Short Setup and Single-minute digit exchange of die (SMED). The idea is that the
changeovers and start-ups will be done in a “single-minute digit,” usually 10 minutes.
A similar concept is a one-touch exchange of die (OTED), where the “single-minute
digit” should be less than 100 seconds.
Redesigning working cells.
Poka-yoke (error-proofing). It is considered the tool that leads the operator to avoid
(yokeru) mistakes (poka). It leads to reducing or eliminating product defects.
Lean manufacturing (or thinking) can help companies gain a competitive advantage. The
core idea is to maximize customer value while minimizing waste (and not compromising
productivity).

Lean is more than a specific tool, management technique, or software package. Lean is
creating and implementing processes that are highly responsive to customer demand.
Lean paves the way for the delivery of high-quality products and services, at the right
location, at the right time, all in a cost-effective manner.

Ideally, the new processes optimize all parts of the value chain so that you do more with
less labour, capital, and time.

1.3 Lean Principles Provide a Framework

Lean Thinking is comprised of five fundamental principles that provide a framework for
creating an efficient organization:

1. Specify Value – End-use customer view
2. Identify Value Stream – Activities that create value
3. Flow – Make value flow
4. Pull – Respond to customer demand
5. Perfection – Zero waste

Lean is Customer First; what is value in the eyes of the customer? What features do they
want? When do they want them and at what price? Without this information, how can you
design your ideal system?

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This value needs to flow from raw materials through to the consumer. This is Just in Time
manufacturing (JIT), producing what the customer wants when they want it. Next, you
strive for perfection, improving everything that you can about the product and process.
This is done by all within your organization, Lean values respect for people, and involves
everyone to help meet customer values.

1.4 Create Value, Eliminate Waste

Lean is a systematic way to see the inefficiencies and address these to grow the
business. To make processes more efficient. To reduce waste and move closer to the
value stream, we use lean thinking. The 8 kinds of wastes (Figures 1.2 and 1.3)
identified in Lean:

Defects
Products or services that are out of specification require resources to correct. Defects
are the result of executed processes that did not produce value.

Overproduction
Waste from producing products that are not currently needed or products that are not
needed at all.

Waiting
Idle time is created when material, information, people, or equipment is not ready. No
value is added while people wait for products to process, or products wait for people or
machines.

Non-utilized Talent
The waste of underutilized intelligence and intellect is commonly referred to as
behavioural waste. When employees are not effectively engaged in the process.

Transportation
Transporting items or information that is not required to perform the process from one
location to another. While the product is moving, no value is added to it.

8 eBook PSP | Lean Manufacturing

Inventory
Inventory and information are queued up between people and processes that are sitting
idle and not being processed.
Motion
Excess movement by people or equipment only consumes time and resources without
producing value. People, information, or equipment make unnecessary motion due to
workspace layout, ergonomic issues, or searching for misplaced items.
Extra-Processing
Performing any activity that is not necessary to produce a functioning product or service.
Doing more than what is necessary to generate satisfactory value as defined by the
customer.

Figure 1.2 The 8 wastes in Lean
Image source: https://www.sixsigmadaily.com/what-are-the-eight-wastes-of-lean/

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Figure 1.3 The 8 wastes in Lean
(Image source: https://goleansixsigma.com/8-wastes/)

1.5 Lean Rules Create a System

Lean rules provide guidance to improve, explaining the “why” behind the tools. For
everyone in an organization, these rules help structure activities, connect customers and
suppliers, specify and simplify flow paths, and bring improvement through
experimentation. The principles of Lean used to provide value can be summarized into
four basic rules:

1. Activity Rule – Specify all work to content, sequence, timing, and outcome.
2. Connection Rule – Customer-supplier connections must be direct & unambiguous.
3. Pathway Rule – Pathways for product/service must be simple & direct.
4. Improvement Rule – Improvements are made using the scientific method (PDCA)

at the place of activity (Gemba) under the guidance of a teacher (Sensei).

10 eBook PSP | Lean Manufacturing

These principles are the building blocks of a Lean production system. They allow
organizations to gain maximum efficiency so everyone can contribute at or near his or
her potential. When the parts come together the whole is much, much greater than the
sum of the parts.

1.6 The Benefits of Lean Manufacturing

In most scenarios, Lean can offer manufacturing companies:
Higher-quality products with fewer defects and rework
Lower levels of inventory
Higher levels of stock turnover
Fewer breakdowns of equipment and processes
More output
Better delivery performance
Greater profits
Happier customers
Enhanced and stronger relationships with vendors
More engaged workers

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12 eBook PSP | Process Considerations in Lean Systems

02

PROCESS
CONSIDERATIONS IN LEAN
SYSTEMS

This topic covers the characteristics of lean systems. It consists of the pull method of workflow,
quality at the source, uniform workstation loads, standardized components and work methods,
flexible workforce, automation, Five S (5S) practices, Total Preventive Maintenance (TPM), small
lot sizes, close supplier ties, and line flow.

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In this section, we discuss the following characteristics of lean systems:
1. Pull method of workflow
2. Quality at the source
3. Uniform workstation loads
4. Standardized components and work methods
5. Flexible workforce
6. Automation
7. Five S (5S) practices
8. Total preventive maintenance (TPM).
9. Small Lot Sizes
10.Close Supplier Ties
11.Line Flow

2 History of Lean Pull Method of Workflow

The majority of companies that practice lean operations use the pull method, in which
customer demand activates the production of a good or service. In contrast, a method
often used in conventional systems that do not prioritize lean systems is the push
method, which involves using forecasts of demand and producing the item before the
customer orders it. Let us use a service example using a favourite activity, eating, to
distinguish between these two approaches.

Imagine yourself at a table in a famous restaurant where you are presented with a menu
of a variety of delicious main courses, appetizers, soups, salads, and desserts. Lamb
chops, chicken chops, grilled striploin beef and pasta are among the options. Choices of
several bestsellers’ salads, soups, and appetizers were prepared in advance at the main
corner of the restaurants. Your order for the salad and the main course signals the chef
to begin preparing your specific requests. This restaurant is using the pull method where
your order has activated the production of the food.

Consider a Nasi Kandar restaurant, where abundant choices of food are ready-prepared
and placed along the restaurant buffet’s line. The chef just estimates the food amount
that is needed by their customers based on the daily demand. This restaurant employs a
push method because it takes a long time to cook certain of the food menu. The
restaurant struggles to use the pull approach where the kitchen only starts processing

14 eBook PSP | Process Considerations in Lean Systems

the food upon receiving an order. Given that customers are already starving, food
shortages could spark riots, yet cooking too much food would be wasteful because it
would go bad. The restaurant must precisely predict the amount to ensure that neither of
these scenarios occurs.
Choosing between the push and pull strategies depends on the circumstances. For
example, in business that employs the assemble-to-order strategy may combine both
methods by manufacturing the standardized components for the push method and
satisfy client requests for specific component combinations for the pull method. The
main characteristics of the push and pull method of the workflow are shown in Figure 2.1.

Figure 2.1 Characteristics of Push and Pull Method of Workflow
Image source: https://kanbanzone.com/resources/kanban/kanban-pull-system/

2.2 Quality at The Source

One of the key characteristics of lean systems is consistently satisfying client
expectations. Adhering to a philosophy of quality at the source principle that states
defects are discovered and fixed where they are formed can lead the way to
accomplishing this goal. An operator must act as a quality keeper or quality inspector

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simultaneously in order not to pass defective items to the next process. Three examples
of quality at the source approaches are Jidoka, Andon, and Poka Yoke.
Jidoka works on the following 4 simple steps to ensure defect-free products in the next
process. Refer to Figure 2.2 for an illustration of Jidoka.

Figure 2.2 Jidoka at the Manufacturing Flow
Notice an abnormality
Stop the process
Fix the immediate problem
Investigate and install countermeasures
Andon works in the following 3 simple steps by giving notification, signal, or alarm when
machines/equipment encountered a problem.
Notice an abnormality
Activate the signal system
Stop production if needed
Andon system can notify the response team using a flag, light, LCD text display, or even
music. The technical team shall respond and attend in situ.
Poka Yoke works as a mistake-proofing method aimed at designing fail-safe systems
that minimize human error. It can be successfully applied to any type of process in the

16 eBook PSP | Process Considerations in Lean Systems

manufacturing or services industry, preventing all kinds of errors. There are 6 principles
of mistake-proofing methods.

Elimination seeks to eliminate the possibility of error by redesigning the product or
process so that the task or part is no longer necessary
Replacement substitutes a more reliable process to improve consistency
Prevention engineers the product or process so that it is impossible to make a
mistake at all
Facilitation employs technique and combining steps to make work easier to perform
Detection involves identifying an error before further processing occurs so that the
user can quickly correct the problem
Mitigation seeks to minimize the effects of errors

Poka-yoke is said to be a successful approach for implementing quality at the source.
We take a real scenario at Toyota plants where every vehicle being assembled is
accompanied by an RFID chip containing information on how many nuts and bolts need
to be tightened on that vehicle for an operation at a given workstation. A green light
comes on when the right number of nuts has been tightened. Only then does the
vehicle move forward on the assembly line.

Designing a part so it cannot be exchanged and miss-positioned are examples of
controls used to prevent human errors (Figure 2.3).

Figure 2.3 Designing a part to avoid miss-exchanged and miss-positioned
(Image source: https://fractory.com/poka-yoke-in-manufacturing/)

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2.3 Uniform Workstation Loads

A lean system works best if the daily load on individual workstations is relatively uniform.
Service processes can achieve uniform workstation loads by using reservation systems.
Scheduled surgeries are implemented for non-urgent cases in a hospital. Differential
pricing is introduced to manage the transportation demand, for example, the airline
ticket price during weekends or the red eye period. Low prices during the red-eye period
can boost the number of tickets purchased.

Uniform loads can be achieved by assembling the same type and number of units each
day, thus creating a uniform daily demand at all workstations for a manufacturing
process. Capacity planning, which recognizes capacity constraints at critical workstations,
and line balancing are used to develop the master production schedule. Followings are
among the activities with the specific term that are carried out in some of the lean
companies.

2.3.1 Takt time
Takt time is the maximum amount of time in which a product needs to be
produced to satisfy customer demand. The term comes from the German word
"takt," which means "pulse."

A production plan calls for 1,200 vehicles per week for the next month that
requires two full shifts, 5 days per week, producing 240 vehicles each day, or 120
per shift. Three models are produced: Myvi (M), Alza (A), and Bezza (B). Suppose
that Perodua needs 60 Myvis, 40 Alzas, and 20 Bezzas per shift to satisfy market
demand. To produce 120 units in one shift of 480 minutes, the line must roll out
a vehicle every 480>120 = 4 minutes. The 4 minutes, or 240 seconds,
represents the takt time of the process, defined as the cycle time needed to
match the rate of production to the rate of sales or consumption.

2.3.2 Heijunka
Heijunka is a Japanese term that refers to a system of production smoothing
designed to achieve a more even and consistent flow of work. It does not build

18 eBook PSP | Process Considerations in Lean Systems

products according to the actual flow of customer orders but levels out the total
volume of orders in a period so that the same amount and mix are being made
each day.
Based on the concept of heijunka, a leveled mixed-model assembly producing a
mix of models in smaller lots can be used to formulate a production schedule for
the products.

Assume that the production requirements at Perodua are in the ratio of 3 Ms to 2
As to 1 V, found by dividing the model’s production requirements by the greatest
common divisor, or 20. Thus, the Perodua planner could develop a production
cycle consisting of 6 units: 3 Ms, 2 As, and 1 V. The cycle would repeat in 6 (4) =
24 minutes, for a total of 20 times per shift (480 min / 24 min = 20).

2.4 Standardized Components and Work Methods

The standardization of components and highly repetitive work increases efficiencies. For
example, a manufacturing company producing 10 products from 1,000 different
components could redesign its products so that they consist of only 100 different
components with larger daily requirements.

When the requirements per components increases, so do repeatability, that is, each
worker performs standardized tasks or work method more often each day. Productivity
tends to increase because, with increased repetition, workers learn to do the tasks many
times thus creating efficiency. Standardized components and work methods promote
high productivity and low inventory, which is the objectives of lean systems.

2.5 Flexible Workforce

Workers at certain workstations can either be increased or decreased to meet the
demand changes. However, it is feasible only if one worker is equipped and trained with
multitasks that suit the works of the company’s products and services.

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In manufacturing, workers can be shifted among workstations to help relieve bottlenecks
as they arise without resorting to inventory buffers. They can also step in and do the job
for those on vacation or sick leave.
Although assigning workers tasks they do not usually perform can temporarily reduce
their efficiency, some job rotation tends to relieve boredom and refreshes workers. At
some firms that have implemented lean systems, cross-trained workers may switch jobs
every 2 hours.

2.6 Automation

Automation plays a big role in lean systems and is a key to low-cost operations. For
example, banks offer ATMs that provide various bank services on demand 24 hours a
day. Another example is the vending machine that offers 24 hours snacks purchase in
the highway stop area (see Figure 2.4). In other instances, especially when production
volumes are high, automation can result in higher quality, precision, and productivity.

Figure 2.4 Vending Machine at Highway Stop Area
(Image source: https://www.foooyo.com/)

2.7 Five S (5S) Practices

5S is a system for organizing spaces so work can be performed efficiently, effectively,
and safely. The system consists of 5 terms that started with the letter S. These letters

20 eBook PSP | Process Considerations in Lean Systems

originated from Japanese words: seiri, seiton, seiso, seiketsu, and shitsuke. As shown in
Figure 2.5, the terms represent activities which are explained below.

Figure 2.5 The 5S diagram
1. Sort (seiri)

Sorting items and storing away those that are not currently needed.
2. Set in Order (seiton)

Arrange items that are needed so that they are ready and easy to use. Identify
locations for all items so that anyone can find them and return them once the task is
completed.
3. Shine (seiso)
Clean the workplace and equipment regularly, to maintain standards.
4. Standardize (seiketsu)
Standardizing all work processes and keeping them consistent thus enable new
workers to step in and perform their job when necessary.
5. Sustain (shitsuke)

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Keeping to the rules to maintain the standard and continue to improve every day.
5S can have a huge impact/change on a workplace. Figure 2.6 below shows conditions
at a workstation before and after the implementation of the 5S approach.

BEFORE AFTER

Figure 2.6 Condition at a workstation before and after the implementation of the 5S approach

(Image source: https://www.leansixsigmadefinition.com/glossary/5s/)

What has been identified for the workplace condition before and after the 5S approach
are as follows:

BEFORE
1. Mixture of needed and unneeded items/tools.
2. No standardized location for essential items.
3. Dirty and messy work area.
4. No standardized housekeeping rules.
5. Excess in motion due to difficulty in reaching items and non-proper work area for the

worker.

AFTER
1. Sort - Keep the needed and dispose of unneeded items/tools.
2. Set in order - Standardized location for essential items.
3. Shine - Remove dirty and messy work areas.

22 eBook PSP | Process Considerations in Lean Systems

4. Standardize - ensuring that what we have done within the first three stages of 5S
becomes standardized in practice.

5. Sustain - Make as practice all 5S rules to sustain a proper work area.

2.8 Total Preventive Maintenance (TPM)

Total Preventive Maintenance (TPM), which is also sometimes referred to as total
productive maintenance, can reduce the frequency and duration of machine downtime.
Replacing parts during regularly scheduled maintenance periods is easier and quicker
than dealing with machine failures during production. Scheduled preventive
maintenance is important for service businesses that depend severely on machinery,
such as the rides at water recreational parks like Sunway Lagoon, Selangor.

Preventive maintenance is performed to reduce the incidence of equipment failure and
the costs associated with it. These costs include disrupted production schedules, idled
workers, loss of output, and damage to products or other equipment. Preventive
maintenance can be scheduled to avoid interfering with production.

Common methods of planning preventive maintenance are based on the passage of time,
on the amount of usage the equipment receives, and on an as-needed basis when
problems are uncovered through inspections. Ideally, preventive maintenance will take
place just before failure occurs to maximize the time that equipment is in use between
scheduled maintenance activities.

2.9 Small Lot Sizes

Lot sizes are kept as small as possible in lean systems. A large number of objects
processed simultaneously is called a lot. Compared to large lots, small lots have the
advantage of having less inventory on average. Since they do not hold materials waiting,
small lots go through the system more quickly than large ones. Large lots also result in
greater delays if any defective goods are found because the entire lot must be checked
to find all the pieces that need to be reworked. Small lots also assist in maintaining a
uniform workload on the system and avoiding overproduction. Large lots complicate
scheduling because they take up a lot of workstation capacity.

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Although small lots are advantageous for operations, they have the drawback of requiring
more setup times. A setup, often known as a changeover, is a collection of tasks required
to adapt or change a process between subsequent sets of products/parts. The test run is
involved in setups, and when the machines are calibrated for the new parts, there can be
a significant material waste. Regardless of the size of the lot, a setup typically takes the
same amount of time. As a result, using frequent small lots rather than a few large ones
may result in waste such as idle workers, equipment, and materials. To benefit from the
advantages of small-lot production, setup times must be short.

Short setup times frequently need strong coordination between engineering,
management, and labour. To achieve a single-digit setup, setup times must be under 10
minutes. Utilizing cranes to move huge dies, simplifying dies, implementing machine
controls, utilizing microcomputers to automatically feed and position work, and preparing
for changeovers while a project is still being processed are some methods used to save
setup times.

2.10 Close Supplier Ties

Companies that employ lean systems must have strong relationships with their suppliers
since they operate with low levels of inventory. Supplies must be of a high standard, sent
regularly, with short lead periods, and arrive on time. Even several times of items
deliveries in a day to a facility could be agreed upon in a contract.

In line with the lean system philosophy, the supply chain should be examined for
opportunities to increase efficiency and decrease inventories. A situation where
businesses and their suppliers work closely together can benefit both parties. For
instance, better component requirements communication enables suppliers to schedule
deliveries and arrange inventories more effectively, increasing supplier profit margins.
After that, customers can bargain for reduced component prices. If firms regard their
suppliers as competitors whenever contracts are negotiated, close supplier relationships
cannot be formed and maintained. Instead, they would need to view suppliers as
partners in a business, with a shared interest in preserving a long-lasting, fruitful
partnership.

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To encourage strong collaborations and better synchronize product flows, the number of
suppliers must be at some limits and make sure suppliers are situated in close
geographic proximity.

2.11 Line Flow

Line flows are recommended in designing lean system layouts because they eliminate
waste by reducing the frequency of setups. If volumes of specific products are large
enough, groups of machines and workers can be organized into a line-flow layout to
eliminate setups. In a service setting, managers of back-office service processes can
similarly organize their employees and equipment to provide uniform workflows through
the process and, thereby, eliminate wasted employee time.
When volumes are not high enough to justify dedicating a single line of multiple workers
to a single customer type or product, managers still may be able to derive the benefits of
line-flow layout—by creating line-flow layouts in some portions of the facility. Two
techniques for creating such layouts are one-worker, multiple-machine cells, and group
technology (GT) cells.

eBook PSP | Manufacturing System 25

26 eBook PSP | Continuous Improvement using Lean System Approach

03

CONTINUOUS IMPROVEMENT
USING LEAN SYSTEM
APPROACH

This topic covers continuous improvement using the lean system approach. It consists of
Kaizen, Kanban system, Value Stream Mapping (VSM), and Just in Time.

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3.1 Kaizen

Lean practitioners often used the word “Kai Zen” throughout the lean journey which
means change for the better. In lean manufacturing, kaizen refers to brainstorming
ideas and implementing daily activities that continuously improve processes. It involves
all employees – from the higher-ups to plant-floor workers.
Kaizen is a part action plan and part philosophy (Figure 3.1).

As a philosophy, Kaizen is about building a culture where all employees are actively
engaged in suggesting and implementing improvements to the company. It shall
become a natural way of thinking for all employees.

As an action plan, Kaizen is about organizing events focused on improving specific
areas within the company. These events involve teams of employees at all levels, with
a strong emphasis to plant floor employees.
A typical Kaizen event works according to the following steps:
1. Set goals and provide any necessary background.
2. Review the current state and develop a plan for improvements.
3. Implement improvements.
4. Review and fix what does not work.
5. Report results and determine any follow-up items.

Figure 3.1 The dual nature of the kaizen system

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3.2 Kanban System

The Japanese word "Kanban," which translates to "card" or "visible record," describes the
cards used to regulate the flow of production through a factory. In simple words, Kanban
is a visual method using a card used to control production flow. Kanban is just a signal
back to the proceeding operation to make the next part.

Typically, there are only two or three cards in the system for each product, though there
can be more if you have to deal with larger batches or if the product size is substantial.
These cards normally provide information on the product, its intended usage, and the
recommended quantities.

A basic Kanban System works according to the following flows:
1. Attach a card to each container of manufactured goods. This container holds a

specific percentage of an item's daily production requirements and essential
information.
2. Take out the card of the container and placed it on a receiving post when any user of
the parts empties the container.
3. The card indicates that another container of the part must be produced when the
empty container has been transported to the storage facility.
4. Replaced the card on the container when it has been filled again.
5. Repeat the cycle.

When a process finishes using the materials to which the Kanban card is attached, the
card is returned to the previous process. This is then used as an authority signal for the
previous process to manufacture replacement parts. For a process that uses more than
one card, the prior process needs to wait for the whole set of cards to be returned before
starting remanufacturing.

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A simple Kanban process that has single piece flow would operate just as in the simple
diagram below (Figures 3.2 and 3.3):

Figure 3.2 Two (2) cards Kanban system
(Image source: https://leanmanufacturingtools.org/kanban/

Figure 3.3 Three (3) cards Kanban system
Image source: https://leanmanufacturingtools.org/kanban/

30 eBook PSP | Continuous Improvement using Lean System Approach

Kanban Bin System
Bins can be utilized quite similarly to Kanban cards. However, the bin in which the goods
are stored becomes the true Kanban rather than the cards that are tied to the materials.
Figure 3.4 and 3.3 below shows a simple diagram of the Kanban bin system that used
two (2) and three (3) bins:

Figure 3.4 Two (2) containers Kanban system
Image source: https://leanmanufacturingtools.org/kanban/

Figure 3.5 Three (3) containers Kanban system
Image source: https://leanmanufacturingtools.org/kanban/

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Rules of Kanban:
The later process collects products from the earlier process.
The later process informs the earlier process of what to produce.
The earlier process only produces what the later process needs.
No products are moved or produced without Kanban authority.
No defects are passed to the later process.

3.3 Value Stream Mapping

Value stream mapping (VSM) is a lean tool that shows material flow, information flow,
and waste improvement opportunities. The VSM enables everyone in an organization to
see the entire value stream on one page. Workers will focus on the big picture and
improving the overall instead of just optimizing a process. The following is a list of
benefits gained from VSM implementation.
1. Helps identify the source of waste in the value stream.
2. Guide the right tool in right place.
3. Provide a common language for process improvement.
4. Shows the linkage between material flow and information flow.
5. Forms the basis of a lean implementation plan through future state mapping.
Figure 3.6 below shows the stages of mapping for VSM:

Figure 3.6 Stages of VSM mapping

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Following are the guidelines to draw a current state map:
1. Conduct mapping by going to the spot.
2. Start with a quick walkthrough of the entire process.
3. Begin mapping the shipping area and work way back to incoming raw materials.
4. Use a pencil to draw the mapping at the spot.
5. Collect real own data. Don’t use standards or hearsay.
The Lean Enterprise Institute's pioneering textbook "Learning to See," which was
released in 2009, introduces several of the symbols used in value stream mapping. The
use of VSM symbols can be customized to meet the needs of the individual company as
they are not standardized. Certain symbols might be insufficient for accurately
characterizing the system you're mapping. Alternatively, you can require certain symbols
to convey certain process elements. The map will be a useful tool as long as the group
charged with developing the system is familiar with the symbols being utilized. Some of
the most typical VSM symbols are listed in Figure 3.7 below.

Figure 3.7 Typical VSM symbols
(Image source: https://www.conceptdraw.com/examples/value-stream-mapping-symbols)

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The following Figures 3.8 to 3.12 shows the diagram of current state mapping steps
example for VSM.

3.3.1 Determine the scope of your value stream map
Create your start and end points first and place them in the top left and right corners of
your document. If you cover the entire supply chain, you will likely start with the
supplier/raw materials and end with the customer. Use the pointed shape (standard icon)
to represent these points.

Under the customer, you’ll record your takt time or the maximum amount of time you can
spend while still satisfying customer demand. To calculate this number, take the
available minutes/ seconds for production and divide it by the required units of
production.

Figure 3.8 Start and end point in the VSM document

3.3.2 Map the steps of your process
Add process boxes (standard icon) to show all the steps involved. In the corner of each
process box, a small circle indicates how many operators complete this step in the
process. The example below shows six (6) persons at the place order station, entering
the order station and serving the food order station respectively. Two (2) persons at the
cook order station. Only one person gathers ingredients, one person prepares and
assembles the order, and one person packages the order.

Below each process box, include a data box for your analysis (standard icon). These
boxes can include, but are certainly not limited to, the following data:

P/T (Process Time): The time it takes to complete a single unit of work
L/T (Lead Time): The time takes one piece to move through a process or a value
stream from start to finish.

34 eBook PSP | Continuous Improvement using Lean System Approach

% C&A (Complete and Accurate): The percentage of time downstream ‘customers’
receive work that is receivable as is.
C/O (Change Over Time): The amount of time required to set up a machine to make a
different product or part number.

Figure 3.9 Map the steps of the processes
3.3.3 Add inventory and wait times
Now connect your start/end points and process boxes with arrows to show the entire
process flow. Thick solid lines represent shipments; in this case, the supplier ships raw
materials to the restaurant, and then the restaurant places the package order to the
customers. The dotted arrows, also called push arrows, represent material pushed from
one process to the next.
In between each stage, use an inventory triangle (standard icon) to mark the number of
orders/parts you have in WIP (work in progress) at the end of each step. On the shipment
arrows, you can also add truck symbols, airplane symbols, or other equipment symbols to
show the method of transportation.

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Figure 3.10 Add inventory/work in progress
3.3.4 Designate the direction of information flows
Value stream maps not only show the production process but also display the flow of
information throughout that process. For example, add a production control box to
represent the people controlling the production. Most people place it between the start
and endpoints. In that box, you can add this group’s responsibilities, for example, place
an order and enter the order.
Then place lines of communication. Jagged lines show electronic communication, such
as email, phone, or fax. You can add notes about the type of data exchanged, the
frequency of this exchange, or the media used. Straight lines show manual
communication, such as memos, printed reports, or in-person conversations. Add
conditional formatting rules to automatically updates shapes and lines when your
process is changed to accurately monitor your information flow.
In this example, a person relates to order receives orders from the lunch patrons by
manual communication and sends bi-weekly forecasts to the supplier electronically and
they communicate with the other production staff by producing food tickets electronically.

Figure 3.11 Designate the direction of the information flow

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3.3.5 Create a timeline
Finally, create a timeline at the bottom of your value stream map. Because value stream
maps aim to detect waste in a process, the timeline is perhaps the most essential piece.
The timeline has two levels. On the bottom, write down the times for process time, taken
from the data boxes above. On top, you’ll write down the times for lead time, and the
non-value-added time. In this example, the lead times are calculated to account for
overproduction.

The timeline also includes a data box to the right that combines all this information. It
commonly houses the following information:

L/T Lead time: the total non-value-added time from the top of the timeline
P/T or value-added time: the total value-added time from the bottom of the timeline
PCE or process cycle efficiency: the percentage of value-added time out of the total
process time

Calculation of individual lead time (L/T):

eBook PSP | Manufacturing System 37

Figure 3.12 Create a timeline and data box.

3.4 Just in Time

Just-in-time (JIT) is an approach to production that was developed by Toyota Motors in
Japan to minimize inventories. Work-in-process and other inventories are viewed as
waste that should be eliminated. Inventory ties up investment funds and takes up space.
To reduce this form of waste, the JIT approach includes several principles and
procedures aimed at reducing inventories, either directly or indirectly. Indeed, the scope
of JIT is so broad that it is often referred to as a philosophy.

JIT is an important component of ‘‘lean production,’’ a principal goal of which is to reduce
waste in production operations. Lean production can be defined as ‘‘an adaptation of
mass production in which workers and work cells are made more flexible and efficient by
adopting methods that reduce waste in all forms.

Just-in-time procedures have proven most effective in high-volume repetitive
manufacturing, such as the automobile industry. The potential for in-process inventory
accumulation in this type of manufacturing is significant because both the quantities of
products and the number of components per product are large. A just-in-time system
produces exactly the right number of each component required to satisfy the next
operation in the manufacturing sequence just when that component is needed—’’ just in
time.’’ The ideal batch size is one part. As a practical matter, more than one part is
produced at a time, but the batch size is kept small. Under JIT, producing too many units

38 eBook PSP | Continuous Improvement using Lean System Approach

is to be avoided as much as producing too few units. This is a production discipline that
contrasts with traditional U.S. practice, which has promoted the use of large in-process
inventories to deal with problems such as machine breakdowns, defective components,
and other obstacles to smooth production.

Although the principal theme in JIT is inventory reduction, this cannot simply be
mandated. Several requisites must be pursued to make it possible: (1) stable production
schedules; (2) small batch sizes and short setup times; (3) on-time delivery; (4) defect-
free components and materials; (5) reliable production equipment; (6) pull system of
production control; (7) a workforce that is capable, committed, and cooperative; and (8)
a dependable supplier base.

3.4.1 Stable Production Schedule
Work must go without major interruptions from regular operations for JIT to be effective.
Changes in production rates, unplanned setups, deviations from the regular work
schedule, and other exceptions are all examples of disruptions that call for
modifications to operating procedures. Upstream processes (i.e., parts feeding) often
amplify disruptions in downstream operations (i.e., final assembly). One method of
establishing a smooth workflow and reducing disruptions and changes in production is
to maintain a master production schedule across time.

3.4.2 Small Batch Sizes and Setup Reduction
Small lot sizes and quick setup times are two criteria for decreasing inventories.
Reducing setup time, thereby permitting smaller lots and lower work-in-process levels.
Some methods for speeding up setup time include (1) performing as much of the setup
as possible while the previous job is still running; (2) using quick-acting clamping
devices instead of bolts and nuts; (3) eliminating or minimizing adjustments in the
setup; and (4) using group technology and cellular manufacturing so that similar part
styles are produced on the same equipment.

3.4.3 On-Time Delivery, Zero Defects, and Reliable Equipment
For JIT production to be successful, on-time delivery, part quality, and equipment
dependability must be practically perfect. Because of the JIT's small lot sizes and part

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buffers, parts must be delivered before running out of stock at downstream stations.
Otherwise, due to a shortage of parts, manufacturing would be stopped at these
stations. If the parts that were given are defective, they cannot be used in the assembly.
These are the reasons why often encourages the production of parts with no defects.
Before moving on to the next operation, employees check their output to make sure it is
free from defects (quality at the source approach). Low work-in-process also calls for
dependable manufacturing equipment. A JIT production system cannot tolerate
malfunctioning machines. This highlights the importance of reliable equipment designs
and preventative maintenance.

3.4.4 Pull System of Production Control
Just-in-time requires a pull system of production control, in which the order to produce
parts at a given workstation comes from the downstream station that uses those parts.
It "places an order" at the upstream workstation to replenish the supply as the supply of
parts runs out at a specific downstream station. This order provides authorization for
the upstream station to produce the needed parts. This procedure, which is repeated at
every workstation in the facility, has the effect of pulling parts through the
manufacturing process.

By contrast, a push system of production operates by supplying parts to each station in
the plant, in effect driving the work from upstream stations to downstream stations. The
risk in a push system is to overload the factory by scheduling more work than it can
handle. This results in large queues of parts in front of machines that cannot keep up
with arriving work.

One famous pull system is the kanban system used by Toyota Motors. Kanban
(pronounced Kahn-Bahn) is a Japanese word meaning card. The Kanban system of
production control is based on the use of cards to authorize production and workflow in
the plant. There are two types of Kanban: (1) production Kanban, and (2) transport
Kanban. A production Kanban authorizes the production of a batch of parts. The parts
are placed in containers, so the batch must consist of just enough parts to fill the

40 eBook PSP | Continuous Improvement using Lean System Approach

container. Production of additional parts is not permitted. The transport Kanban
authorizes the movement of the container of parts to the next station in the sequence.

For more explanation of operation in the Kanban system, refer to Figure 3.13 how the
two workstations, feeds each other.

The figure shows four stations, but B and C are the stations we want to focus on
here. Station B is the supplier in this pair, and station C is the consumer. Station C
supplies downstream station D. B is supplied by upstream station A.

When station C starts work on a full container, a worker removes the transport
Kanban from that container and takes it back to B. The worker finds a full container
of parts at B that have just been produced, removes the production Kanban from
that container, and places it on a rack at B.

FIGURE 3.13 Operation of a Kanban system between workstations

The worker then places the transport Kanban in the full container, which authorizes
its movement to station C.

The production Kanban on the rack at station B authorizes the production of a new
batch of parts. Station B produces more than one-part style, perhaps for several
other downstream stations in addition to C.
The scheduling of work is determined by the order in which the production Kanban
is placed on the rack.

The operation of the Kanban pull system between stations A and B, C, and D is identical
to that of the system described here between stations B and C. This production control

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system eliminates unneeded paperwork. Instead of generating new manufacturing and
transport orders with each cycle, the cards are continuously reused.

The manual material handling by labour (carrying cards and containers between
stations) is an obvious drawback, however, it is suggested that this encourages
employee collaboration and teamwork.

3.4.5 Workforce and Supplier Base
A JIT production system also needs workers who can multitask, cooperate, and are
committed to their jobs. To prevent significant breakdowns, the workers must be
adaptable to make a variety of part styles at their assigned workstations, check the
quality of their work, and resolve small technical issues with the production equipment.
Just-in-time also applies to the company's suppliers of materials and components.
Suppliers must adhere to the same JIT requirements as the company itself, including
on-time delivery, zero defects, and other requirements.

Some of the vendor policies used by companies to implement JIT include:
1. decreasing the overall number of suppliers.
2. choosing vendors that have a track record of achieving quality and delivery

standards
3. forming long-term relationships with vendors, and adhering to other JIT

requirements as the company does.

42 eBook PSP | Continuous Improvement using Lean System Approach

Case Study 1

The SSB company had a machine utilization rate of 50% and a turnaround time of 15
days before implementing lean manufacturing. But a low utilization rate is a synonym for
waste. This company is adopting lean management as they believe it is important for
their company to survive and compete with others. As in any lean implementation, the
changes are gradual.
One of the first measures was the effort to cut distances travelled by parts and goods
within the factory. To lessen overproduction, SSB introduced visual management of
Kanban cards right away. The Kanban cards alert workers when the next stock is running
low. It serves as the basis of the "pull," as opposed to the "push," system. These cards
provide information about what to produce when to generate it, and how much. It allows
for better control of transitional stocks throughout the production cycle, improving
flexibility and lowering costs.
Workers don't find the tools they require very often and frequently have to move from one
station to another. To arrange the tools properly, a shadow board was employed. To
make sure that tools were kept in the correct location, labels were employed.
Demonstrating results is a key element in the spread of the lean philosophy across the
company. To have the greatest effect on other employees, a model of excellence was
established. Floors under the machines were painted white to detect early wear, prevent
corrective maintenance, and favour preventive maintenance. SSB lean manager also

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made sure that all the equipment, resources, and data necessary for workers are
concentrated in a defined area to reduce the amount of travel for the workers. A
champion among the workers will be nominated from each cell to help advance and
maintain lean initiatives over time. Unsurprisingly, SSB discovered its “unseen factory” of
unused equipment and mess, even though it took pride in being a fairly clean factory.

Questions

1. List the 5S and compare it to the lean implementation at SSB. Explain them.
2. Describe which kind of waste was eliminated for each lean implementation at SSB.

Can you think of other types of waste that could be eliminated?
3. Considering SSB’s situation, explain which elements of the lean system you would

further implement and what would be their positive consequences on the company.