QUALITY CONTROL

QUALITY CONTROL

Topic 1

FAUZUREEN FUDZIL

JABATAN KEJURUTERAAN
MEKANIKAL
POLITEKNIK SEBERANG PERAI

QUALITY
CONTROL

Fauzureen Fudzil
2021

[Mechanical Engineering Department]

©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.

ii PSP eBook | Quality Control - Topic 1

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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Perpustakaan Negara Malaysia Cataloguing-in-Publication Data

Fauzureen Fudzil, 1981-
QUALITY CONTROL. Topic 1 / FAUZUREEN FUDZIL.
Mode of access: Internet
eISBN 978-967-0783-89-5
1. Quality control.

2. Total quality management.
3. Government publications--Malaysia.
4. Electronic books.
I. Title.
658.562

PSP eBook | Quality Control - Topic 1 iii

Acknowledgement

First and foremost, I would like to praise Allah the Almighty, the Most Gracious, and
the Most Merciful for His blessing given to me in completing this eBook. I would like to
express my gratitude and sincere thanks to Head of Mechanical Department, Mr.
Muhammad Nasir bin Marzuki, who has given me his valuable guidance, advice, and
encouragement so I could complete this eBook in time.
My ultimate thanks are dedicated to my beloved family and friends for their endless
support, love, and prayer. Special thanks to to the director of Politeknik Seberang
Perai, Sr. Harith Fadzilah Bin Abd Khalid for his guidance, understanding and
invaluable advice throughout the duration of this writing and publishing this eBook.

Fauzureen Fudzil

iv PSP eBook | Quality Control - Topic 1

Preface

This DJF51082 QUALITY CONTROL eBook, it has been provided for Mechanical
Engineering Department Students in semester 5.

The knowledge of quality control management is highly essential for all engineers and
technocrats for familiarizing themselves with modern concepts of manufacturing
technologies. Therefore, an attempt has been made through this eBook to present
both the theoretical and practical knowledge of these subjects.

PSP eBook | Quality Control - Topic 1 v

Table of Content Pages

Chapter 1
1
1.1 EXPLAINING BASIC QUALITY CONCEPT 2
Quality 2
Quality to customer and society 3
Zero Defect 3
Internal and external customer 3
Quality associated terms and concepts 5
i. Quality Control 5
ii. Quality assurance 7
iii. Total Quality Management (TQM) 7
iv. Continuous Improvement
v. Six Sigma 10

1.2 EXPOSE ISO 9000 SERIES FOR QUALITY SYSTEM 10
MANAGEMENT 11
12
a. The Need of a Quality System 17
b. Quality Management Principles
c. Basic Concept and Main Terms in ISO 9000 Series 20
Advantages And Disadvantages of Practicing ISO9000 Series 22
23
1.3 APPLY BASIC STATISTIC IN QUALITY CONTROL 27
Ungrouped Data 28
Grouped Data 28
EXERCISE 1.1
EXERCISE 1.2 vi
EXERCISE 1.3

References



1TOPIC PSP eBook | Quality Control - Topic 1 1

BASIC QUALITY CONCEPT

1.1 EXPLAINING BASIC QUALITY CONCEPT

Quality

Quality as a function of customer satisfaction. The ability of a product or service
to consistently meet or exceed customer expectation.

Quality is conformance to Quality is fitness for use.
(Juran 1974)
requirements or

specifications. (Crosby

1979)

Custome
r

Product Marketing
Service

Packaging Quality Design
and Storage Product Engineering

Inspection Procureme
and Test nt

Production Process
Design

Figure 1.1 Areas responsible for quality

2 PSP eBook | Quality Control - Topic 1

Quality to customer and society

a. Many companies stated that measure of quality was customer satisfaction.
An organization must give its customers a quality product or service that
meets their needs.

b. Customer satisfaction.
What was acceptable 10 years ago maybe rejected today. Expectation is
constantly changing. To attain this, the organization continually needs to
examine its quality system to see if it is responsive to ever-changing customer
requirement and expectations.

Zero Defect

It is motivating people to prevent mistakes by developing a desire to do their job
right the first time.
a. Do it right and best from the beginning/ at the first time
b. Quality prevention is preferable than quality inspection and correction.
c. Opened relationship between workers and employer.
d. Management must be persistent in efforts to achieve good quality.

Cause Intermediate Result End
Result
Work Machine Detect Take
Procedure or error Corrective ZERO
DEFEC
Human Error Action
T

Modify work Analyse for
procedure to preventive action
prevent such errors

Figure 1.2 Zero Defect Model

PSP eBook | Quality Control - Topic 1 3

Internal and external customer

a. Internal customer
The internal customer is those in the next operational sequence. Some
examples are Salesperson, Machine Operator and Shipping Supervisor.
Employee who receives goods or service produced elsewhere in the company
as input to his or her works in the organization.

b. External Customer
The user. If you are the manufacturer, the external customer is the shop
owner, and the people who used your service.
An outside organization or individual that receives a product or service from
the company.
Organizations are dependent upon their customers. If they do not
develop customer loyalty and satisfaction, they could lose their
customers.
Without customers the organization would not exist.
The purpose of the organization should be to fulfill the needs of the
customers.
The customer makes it possible to achieve business aims.

Quality associated terms and concepts

i. Quality Control
Control refers to the process for achieving the standard or standards.
Control involves the process of observing the actual performance,
comparing performance with standards, and take action if performance
does not meet the standards.
Quality control is therefore defined as techniques or activities used to
meet, reach, support, and enhance the quality or service.
1. Establishment of a product or service specifications required.
2. Design a product or service to meet specifications.

4 PSP eBook | Quality Control - Topic 1

3. Production or assembly to meet the full requirements
specification.

4. Inspections to ensure compliance with specifications.
5. To review of the use of specifications for information amendment

if necessary.
The objective of the quality control:

1. To achieve acceptable levels of consumer goods from the time
of shipment until the time of consumption or achieving quality of
products according to specifications.

2. Achieve the lowest cost of goods.
3. Conform to the period of completion and delivery of the goods

as promised.
4. To monitor the quality of incoming raw materials, in process

and finished materials.
5. To evaluate the appropriateness of the standards process.
6. Optimum quality assessment.
7. To improve productivity and quality improvements.
8. The quality awareness.
9. Improve customer service.
The importance of the quality control:
1. To providing quality products to customers.
2. The scrap and failure can be controlled.
3. To adjustments the processes and machines.

Benefit of quality control:
1. Improve the quality.
2. Increase production under optimum conditions.
3. To reduce the cost per minute.
4. Reduction in scrap.
5. Savings in material usage.
6. Reduction the bottleneck in production.
7. Reduction in inspection.

PSP eBook | Quality Control - Topic 1 5

8. Quality awareness.
9. Reduce grievances or complaints.
10. Maintenance of operational efficiency.
ii. Quality assurance
Plans and systematic actions necessary to provide confidence to
customers that the products or services will meet or satisfy the quality
requirements, specifications and standards set.
Include some measure of common standards, such as dimensions, surface
finish, limitations and tracks, colour and mechanical conditions.
Example: ISO 9001 recognition, JAKIM’s Halal certification, and warranty
cards.
iii. Total Quality Management (TQM)
TQM is a continuous improvement process to improve performance at
every level and every area in your company or organization.
TQM is defined as a system of management based on the principle that
every staff member must be committed to maintaining high standards of
work in every aspect of a company's operations.
It is the process of individual and organization development purpose of
which is to increase the level of satisfaction of all the stakeholders.
The increase can be seen in terms of direction, such as cost, quality and
delivery.
TQM incorporates the basic management techniques, leadership,
improvement efforts, and skills courses in the orderly structure of the
focus to continuously improvement all processes in a company or
industry.
TQM also emphasizes the commitment and discipline, interdependence
between workers and involving all.
TQM reminds us not only to focus on the quality of products
produced or services provided to customers, but all the things that we
run, such as production, services and business processes.

6 PSP eBook | Quality Control - Topic 1

Involving areas are such as declaration, sale, management materials,
production design, forecasting, marketing, storage (inventory) and last
sale.

Customer Input

Accounting Personnel

Installation Marketing / sales

Product Product Finance
Shipping quality and
Customer Product design and
development

Packaging Product
Engineering
Testing and Purchasing
Inspection
Engineering
Manufacturing

Figure 1.3 Total Quality Management Involving Area

Basic concepts of TQM:
1. Management who are committed and engaged to provide a
comprehensive long-term support.
2. To emphasis on internal and external customers.
3. The involvement and extensive use of an effective workforce.
4. To continuous improvement in trade and production processes.
5. To treat suppliers as partners.
6. The implement achievement of emphasis for each process.

The main principles of TQM:
1. The quality should be focused on customer.

PSP eBook | Quality Control - Topic 1 7

2. To continuous improvement efforts by each member of the group.
3. Full staff involvement in customer-supplier chain.
iv. Continuous Improvement
A continual improvement process, also often called a continuous
improvement process, is an ongoing effort to improve products, services,
or processes. These efforts can seek "incremental" improvement over
time or "breakthrough" improvement all at once.
Important steps for continuous improvement:

1. To create a resolution determination to improve products and
services.

2. To accept and embrace a new philosophy.
3. Do not rely on large-scale screening. On the other hand,

statistical evidence is needed to proof that quality control
activities were conducted.
4. Do not choose a supplier or business based on price.
5. It was the duty of management to locate and identify problems.
6. Introduce modern methods to supervise production workers.
7. To create a harmonious working environment so that
employees can work effectively.
8. To overcome the barriers between departments.
9. Provide a means to increase productivity.
10. To eliminate work standards that determine goods quota.
11. To remove obstacles that prevents temporary workers to
demonstrate their work skills.
12. To introduce education and retraining programs.
13. Creating a management structure that push things over.

v. Six Sigma

Six Sigma is a business management strategy, originally developed by
Motorola in 1986.
Six Sigma seeks to improve the quality of process outputs by identifying
and removing the causes of defects (errors) and minimizing variability in

8 PSP eBook | Quality Control - Topic 1

manufacturing and business processes. It uses a set of quality
management methods, including statistical methods, and creates a
special infrastructure of people within the organization ("Black Belts",
"Green Belts", etc.) who are experts in these methods.
Each Six Sigma project carried out within an organization follows a
defined sequence of steps and has quantified financial targets (cost
reduction and/or profit increase).
A six-sigma process is one in which 99.99966% of the products
manufactured are statistically expected to be free of defects (3.4 defects
per million).
Six Sigma identifies several key roles for its successful implementation.
1. Executive Leadership includes the CEO and other members of top

management. They are responsible for setting up a vision for Six Sigma
implementation. They also empower the other role holders with the
freedom and resources to explore new ideas for breakthrough
improvements.
2. Champions take responsibility for Six Sigma implementation across the
organization in an integrated manner. The Executive Leadership draws
them from upper management. Champions also act as mentors to
Black Belts.
3. Master Black Belts, identified by champions, act as in-house coaches
on Six Sigma. They devote 100% of their time to Six Sigma. They assist
champions and guide Black Belts and Green Belts. Apart from statistical
tasks, they spend their time on ensuring consistent application of Six
Sigma across various functions and departments.
4. Black Belts operate under Master Black Belts to apply Six Sigma
methodology to specific projects. They devote 100% of their time to Six
Sigma. They primarily focus on Six Sigma project execution, whereas
Champions and Master Black Belts focus on identifying
projects/functions for Six Sigma.

PSP eBook | Quality Control - Topic 1 9

5. Green Belts are the employees who take up Six Sigma implementation
along with their other job responsibilities, operating under the
guidance of Black Belts.

Six Sigma projects follow two project methodologies inspired by Deming's
Plan-Do-Check-Act Cycle. These methodologies, composed of five phases

each, bear the acronyms DMAIC and DMADV.

1. DMAIC is used for projects aimed at improving an existing
business process. DMAIC is pronounced as "duh-may-ick".

2. DMADV is used for projects aimed at creating new product or
process designs. DMADV is pronounced as "duh-mad-vee".

The DMAIC project methodology has five phases:
1. Define the problem, the voice of the customer, and the
project goals, specifically.
2. Measure key aspects of the current process and collect
relevant data.
3. Analyse the data to investigate and verify cause-and-
effect relationships. Determine what the relationships
are and attempt to ensure that all factors have been
considered. Seek out root cause of the defect under
investigation.
4. Improve or optimize the current process based upon
data analysis using techniques such as design of
experiments, and standard work to create a new,
future state process. Set up pilot runs to establish
process capability.
5. Control the future state process to ensure that any
deviations from target are corrected before they result
in defects. Implement control systems such as
statistical process control, production boards, visual
workplaces, and continuously monitor the process.

10 PSP eBook | Quality Control - Topic 1

Some organizations add a Recognize step at the beginning, which is
to recognize the right problem to work on, thus yielding an RDMAIC
methodology. DMADV or DFSS.
The DMADV project methodology, also known as DFSS ("Design
For Six Sigma"), features five phases:
1. Define design goals that are consistent with customer demands

and the enterprise strategy.
2. Measure and identify CTQs (characteristics that are Critical To

Quality), product capabilities, production process capability,
and risks.
3. Analyse to develop and design alternatives, create a high-level
design and evaluate design capability to select the best design.
4. Design details, optimize the design, and plan for design
verification. This phase may require simulations.
5. Verify the design, set up pilot runs, implement the production
process and hand it over to the process owner(s).

1.2 EXPOSE ISO 9000 SERIES FOR QUALITY SYSTEM MANAGEMENT

a. The Need of a Quality System
Quality system is a standard to help all type and size of organization to
achieve the effective quality management system. It should emphasis on the
effectiveness of an organization to manage their organizations to produce
products or services that meet the needs and expectations of customers and
stakeholders in accordance with which it was established.

A standard is required to highlight the main basic to form and achieve the
effective quality management system and fulfil the purpose of
establishment and efficiency in producing outputs or services to meet the
needs and expectations of customers and interested parties, and in
accordance with legal provisions and related regulations.

PSP eBook | Quality Control - Topic 1 11

MS ISO 9000: M=Malaysia, S= Standard, ISO= International Standard
Organization (International Organization for Standardization), 9000=
standard reference number that sign by ISO.

b. Quality Management Principles
8 Basic principle standard ISO 9000.
1. Focus on Customer.
Organization is created because of customer. Organization needs to
understand the customer needed for current and future. The
existing of quality system by organization should fulfil customer
needed. The creation of this organization's quality system shall
endeavour to provide services that exceed customer expectations.
2. Leadership.
Management agreement should be created in guide to achieve the
creation of organizations. Management agreements are responsible
to:
1. Set the direction, policies and strategies of the organization,
providing the necessary resources and planning and
controlling production processes for products or services.
2. Establish quality objectives at all functions and levels of the
organization. Failure to achieve the objectives of this quality
may mean that top management need to review policies and
strategies of the organization.
3. Review the quality management system to ensure it remains
appropriate and effective. But the quality should be
evaluated in terms of the changes and improvements that
need to be introduced.
4. Measure and control the processes in the organization to
ensure that the objectives can be served by it. If these
objectives cannot be achieved due actions to be taken to
ensure that it can be achieved.

12 PSP eBook | Quality Control - Topic 1

5. Creating and maintaining the office environment that allows
employees fully engaged in achieving organizational goals.

3. Involvement in an organization.
All members are important resources to the organization.
The involvement and competence of members are necessary
to contribute to performance improvement.

4. Approach process.
Approach process is meant input, the transformation process inputs
and outputs to the transformation process are identified. Desired
results, the output of this transformation process can be more
efficiently served by it when the activities and resources involved
are managed according to an approach process.

5. Approach systems management.
Approach systems means that all processes are identified and dealt
with the relationship so that objectives can be achieved more
effectively.

6. Continuously improvement.
Efforts of continuous improvement should be permanent objectives
of the organization. Organizations need to plan and take action
towards continuous improvement of its quality management
system. This action may be taken based on the quality policy, quality
objectives, audit results, analysis of data, corrective and preventive
actions and management review.

7. Approach makes the decisions base of facts.
Decisions should be based on accurate data and
information so that these decisions more effectively.

8. Relationships with suppliers for mutual benefit.
Organization and its suppliers interdependent with each
other. Good relations would benefit and enhance the
performance of both parties.

PSP eBook | Quality Control - Topic 1 13

c. Basic Concept and Main Terms in ISO 9000 Series
Focus on handling the process that relate in product or service output.
To ensure the organization are using the shorten process to improve the
efficient and effective organization management system. Hence,
customer expectation and important people can be fulfilled.
Concentrate on planning and source preparing include managing,
controlling, evaluating, and process archiving in organization to produce
service and product that according to establishment purpose.
Introduction to ISO 9000:
1. ISO (International Organization for Standardization) Establishment
of standards of national standards bodies of the world, to provide
international standards conducted by a committee known as the
ISO Technical Committee and start delegated on March 1987(ISO
9000: 1987). That committee is known as ISO/Technical
Committee 176 (ISO/TC 176).
2. A guideline to designing, manufacturing, services and sales of a
product.
3. Standard are imposed on every individual in the organization.
Hence, a uniform system is obtained.
4. In our Malaysian version of ISO, the first version was MS ISO
9000:1987. The version was reviewed on Mac 1993 and start
reused from 1994 and known as MS ISO 9000:1994. A new version
was introduced on year of 2000 (MS ISO 9000:2000) that 3 main
models only are available. The following version was in 2008 (MS
ISO 9000:2008/9).
5. The latest version is MS ISO 9000:2015 can be applied when an
organization has established a systematic approach to instil
quality by ensuring that their products meet customer
requirements. This does not mean that the product is conforming
to product standards. It means that the products are being
produced through processes which have consideration for quality
in the aspects set out by the standard.

14 PSP eBook | Quality Control - Topic 1

6. As new version was revised, new focus of QMS through ISO was
also introduced to ensure better quality that suits the current
industrial requirement and customer’s needs.

7. Even though ISO 9000 have been studies in every 5 years, but
every new version is taking 1 to 3 years for transition period. For
example, 1993 version must be studies on year 1992 (5 years from
1987), 2000 version must be studies on year 1999 (5 years from
1994).

8. Every activity that affects the quality of an organization must
be planned, controlled, and documented, for the purpose of:
i. Understanding of objective and methods of quality,
ii. Smooth interaction in organization, and
iii. Feedback for planning cycle.

5 basic elements in ISO 9000 structure:
1. Vocabulary.
2. Management standard and quality guaranty.
3. Standard and specificity achievements quality guaranty.
4. Guideline for audition quality system.
5. The needed of quality guaranty for measurement tools.

Elements and concepts for solving the quality systems.
1. The needed of conflicts balance:
i. Customer must get the quality product in reasonable cost.
ii. Your company must produce the quality product in
reasonable cost.
2. Gain
i. When selling the product, both of seller and customer
must
gain.
ii. Customer must buy the product that fulfil needed.
iii. Your organization must sell the product in suitable price.
3. Cost

PSP eBook | Quality Control - Topic 1 15

i. Customer has to reduce the purchase cost, operation cost,
maintenance cost, improvement cost.

ii. Your company has to reduce redesign cost, repairing cost,
replacement cost, reprocessing cost, producing cost,
storing
cost, caring cost, maintenance cost, and marketing cost.

4. Risk
i. Customers have to control the risk such as health, safety,
environment operation and financial.
ii. Your organization has to control the risk such as law,
ethics,
and financial cause by problems of product.

ISOs overall mission is built on the following core initiatives for its
members:

1. Strengthening the links between standardization and public policy
by providing thought leadership and promoting awareness of best
practices.

2. Identifying and building national standardization strategies by
applying best practices.

3. Ensuring the efficient operation of their organizations while
managing financial.

4. Sustainability and risk.
5. Ensuring participation of, and collaboration with, key stakeholders

in all standardization projects.
6. Increasing adherence to Good Standardization Practices (GSP)

among standards experts in every national organization and
evaluating all processes to determine their alignment with the
World Trade Organization (WTO) Technical Barriers to Trade (TBT)
Agreement.
The used of documents in ISO 9000, ISO 9001, ISO 9002, ISO 9003 AND
ISO 9004 SERIES.

16 PSP eBook | Quality Control - Topic 1

ISO 9000
i. Quality Management Systems- Fundamentals and Vocabulary.
ii. It is a guideline for organization to choose the types of
standards
to be used.
iii. To highlight the concept, basic principle and definition for
quality management systems.
iv. Certificate is would not give to organization if using this
standard.

ISO 9001
i. Quality Management Systems- Requirements.
ii. It is used by organization or company that relate to industry or
the course that conduct design activity and product producing
and service to obtain the certificate recognition.
iii. This standard is highlighting the needs in a quality
management system.
iv. MS ISO 9000:2008 is the Fourth Edition after the First Edition
(1987), Second Edition (1994) and Third Edition (2000).
v. The Third Edition is replaced for all version of standard model
in
1994, MS ISO 9001:1994, MS ISO 9002:1994, and MS ISO
9003:1994.
vi. Organization needs to fulfil the standard of MS ISO 9001:2008
for certification.

ISO 9002
i. Quality Management Systems- Requirements (without
designing).
ii. It is used by organization or company that conducts in product
producing industry only (without designing) and obtains the
certification recognition.
iii. This standard is a quality guaranty model that use by
organization in producing, installing and product maintenance.

PSP eBook | Quality Control - Topic 1 17

iv. Containing 19 requirements in quality systems. 4th item:
product design has been deleted. Other requirements are the
same to requirement in ISO 9001 model.

v. This model has been discontinued starting from version 2000.

ISO 9003

i. Quality Management Systems- Requirements (checking and
testing).
ii. It is used by organization or company that conducts checking
and testing activities only and obtains the certificate
iii. recognition.
Requirement in 4th item: product design, 6th item: purchase
ISO 9004 iv. requirement, 9th item: control process requirement, and 19th
i. item: maintenance requirement but no include internal model.
This model has been discontinued starting from version 2000.
ii.
Quality management systems- guidelines for performance
iii. improvements.
It is a guideline to archive the quality management and quality
system elements for continuously improvement on overall
performance of an organization.
No certificate is issued to organizations that use this standard.

Advantages And Disadvantages of Practicing ISO 9000 Series.
The advantages in archive the ISO 9000 quality system standard.

Establish a management system in terms of proper and systematic documentation
of controls, procedures, quality procedures, and quality control records.
Encourage continuous improvement.
Responsible management system can be created, that is proper planning, a clear
statement of objectives and a good communication system.
To create a teamwork system to guaranty the customer
satisfaction.

18 PSP eBook | Quality Control - Topic 1

Reduce the need to make corrections in the process because all the processes,
tasks or steps that must be detailed in the form of a complete procedure. Careful
planning can prevent problems from occurring.
Enable the organization to identify problems, causes and prevent it in the future.
Corrective actions are the basic elements of ISO 9000 in a planned, orderly and
controlled.
To help management to make better decisions and effective.
Staff to perform tasks efficiently and correctly the first time and every time because
the planned work.
Customers will have high regard for the company gained recognition ISO 9000, and
the products or services received is considered and accepted as the best.
Three main categories:

1. International.
Because many companies in other countries have been implementing the
ISO 9000, then other companies to penetrate the international market.
Facilitate the international trade because products are guaranteed.
Large companies often purchase components
produced by other countries and are very concerned about quality
assurance and consistency of product quality.

2. Local
Increasing the level of competition that can match an organization that has
been recognized standard of quality and leading companies that have not.
Improve the market access.

3. Inland
Increase the customer satisfaction.
Increase the productivity and reduce the cost.
Experience and quality improvement.
Using the ISO 9000 standards in the use of a
wider quality system.
Reducing the inspection for confidence in the quality of the product.

PSP eBook | Quality Control - Topic 1 19

The disadvantage in implementation ISO 9000 quality system standards.
i. Because of all duties and procedures have been set, then the employees will
become less creative or less initiative, and just to procedures only.
ii. Company that received ISO 9000 recognition can only be proven through
documentation of their compliance work alone. This is not enough to produce
quality work, but easy to follow procedures.
iii. Not at all areas or activities in an organization that will be monitored during ISO
certified. A quality system cannot exist separately from the overall system
contained within an organization. Failure of a comprehensive quality control cannot
produce quality work.

Examples of methods for labelling and marking ISO.

Motorcycle companies have to apply for ISO 9001 recognition. Steps taken:

1. Company is required to apply for the ISO 9001 certificate
of recognition.

2. Evaluation of documents design and production.
3. Acceptance for assessment for pre-registration.
4. The SIRIM or MAMPU to assess plant.
5. Recommendations for awarding certificates.
6. SIRIM or MAMPU approval.
7. To do annual surveillance audit for renewal of certification.

ISO 9000:2015
i. ISO 9000:2015 series is a new ISO standard that emphasizes
Quality Management System (QMS) that requires quality assurance. The
series is set requirements appropriate to an organization's ability to
demonstrate quality assurance and evaluation capacity through audit and
or review process.
ii. ISO regularly reviews all standards to ensure they are up-to-date and
continue to be relevant for the needs of organizations around the world.
The last major revision of ISO 9001 was in 2008. The exponential increase

20 PSP eBook | Quality Control - Topic 1

in the availability of technology, products, and services for consumers, as
well as the size and complexity of the global supply chain, have meant that
ISO needed to make 9001 meet several new requirements. Customer
demands on products and services, and the impact on the brand
reputations of those companies that can meet them, grow each day, and
ISO 9001 needed to meet these enhanced expectations.
The types of categories of documents in the ISO 9000:2000

1. Quality Manual (Quality Manual) (Why)
2. Procedures (Procedures) (Who, What, When, Where)
3. Work order (Work Instruction) (How)
4. Records (Records) (Evidence)
Among the documents that must be provided in the QMS
1. Control of documents
2. Control of records
3. Internal audit
4. Control of nonconforming product
5. Corrective action 6. Precaution
ISO 9001:2015 and its complementary management standards are based
on the following seven Quality principles.

Table 1.1 Quality Principle

PRINCIPLE DESCRIPTION

Customer Customer focus means exceeding customer
Focus expectations and providing satisfaction and value
with every customer interaction. It requires an
organization to link every business objective to
customer needs and to recognize that customers
are those that have both direct and indirect
relationships with an organization.

Leadership Leadership must commit to ensuring the availability
of all resources for Quality projects and to providing
positive role models through active participation,

PSP eBook | Quality Control - Topic 1 21

Engagement proactive communication of vision and strategy,
of People and an organization-wide engagement with a
Culture of Quality.
Process Organizations must engage and empower
Approach competent and motivated workers while
encouraging everyone to contribute and
Improvement collaborate.

Evidence- A process approach recognizes that processes must
Based be part of a unified and consistent system that
produces predictable results, illumines elements
Decision that require improvement, and addresses all risks
Making that have an impact on process outcomes.

Relationship An ongoing dedication to improvement reacts to
Management changes in external and internal conditions to
create new opportunities by focusing on root-cause
determination and preventative and corrective
actions.

Making decisions based on statistical evidence
provides greater objectivity, effectiveness, and
efficiency to an organization and makes it easier to
review results for ongoing improvement.

Organizations must account for and manage
relationships with all vendors, partners, and
suppliers to understand the constraints,
opportunities, and risks for each.

1.3 APPLY BASIC STATISTIC IN QUALITY CONTROL

To analyse data collected from a process, some kind of statistics can be calculated to
facilitate the analysis.
Statistics is a science that deals with the collection, tabulation, analysis,
interpretation and presentation of quantitative data.
Two techniques are available to summarize data:

22 PSP eBook | Quality Control - Topic 1

i. Graphical technique – plot or picture of a frequency distribution
ii. Analytical technique- summarizes data by computing a measure of

central tendency and a measure of the dispersion.

Measures central tendency was presented by value of mean, mode and median.

Meanwhile measures of dispersion was presented by value of range and standard

deviation.

Mean (average), ,̅ is average for a set of data.

Mode is the value with highest frequency.

Median is the number in the middle of the set when the numbers are arranged in

order from least to greatest.

Range is difference between the largest and the smallest values in the observation.

Standard Deviation is numerical value in the units of the observed values that

measures the spreading tendency of the data.

Data can be divided into grouped data or ungrouped data.

Data that have been grouped means a set of data that is tabulated and distribute

into range and frequency; whereas ungrouped data are not.

About mean median and mode:

Negatively skewed Normal (No skewed) Positively skewed

Mode Mode
median median

Frequency mean mean

Negative The normal curve represents Positive
direction perfectly symmetrical distribution direction

Figure 1.4 Normal Curve Distribution

1) Data analysis by calculating mean, range and standard deviation for:
Ungrouped Data

▪ Mean, ̅

PSP eBook | Quality Control - Topic 1 23

̅ = =∑ =1 1+ 2+ ….+



▪ Median = The middle number/ Average of the middle number
▪ Mode = The value that occurs with the greatest frequency
▪ Range

= −
XH = highest observation value in a series
XL = lowest observation value in a series

▪ Standard Deviation

= √(∑ 2)− ̅2 (population)



= √(∑ 2)− ̅2 (sample)

−1

Grouped Data

▪ Mean, ̅

̅ = ∑ where x = midpoint
∑

▪ Median = The middle number/ Average of the middle number

▪ Mode = The value that occurs with the greatest frequency

▪ Range

= −
XH = highest observation value in a series
XL = lowest observation value in a series

▪ Standard Deviation

= √∑[ ( − ̅ )2 (population)

∑

24 PSP eBook | Quality Control - Topic 1

= √∑[ ( − ̅ )2 (sample)

∑ −1

2) Building Frequency Distribution Table (Converting Ungrouped Data to Grouped Data)
Frequency Distribution Table can be formed from the raw data obtained. The
purpose is to compile the data and allow us to easily get some features of the data
that has been collected.
▪ Steps To Build Frequency Distribution Table.
a. Determine the range, R
b. Determine the cell interval, i.

= , = 1 + 3.3 log



where K = estimated number of classes
n = number of observation

c. Determine the frequency

3) Normal Curve shape and calculate the area under normal curve by using the Z table.
In any industrial product, different population of product will create a
different condition which can be described in a variety of form and shape.
The most common method used is normal curve, also known as the Gaussian
distribution.
It is a symmetry curve graph, with only one peak, and the distribution shape
looks like a bell with the value of mean, median, mode at the same line.
It’s generated from the histogram with large sample size and small class
interval, the normal curve that is obtained will be a smooth bell-shaped
and symmetrical.

PSP eBook | Quality Control - Topic 1 25

Figure 1.5 (a) The Normal Curve Bell-shaped
All normally scattered graphs can be change to normal distribution using
the normal standard, Z.

Figure 1.5 (b) The Normal Curve Bell-shaped
Normal curve is usually being used to calculate the probability value.
The relationship between normal curve, mean and standard deviation are as
follows:
a) Mean changes, the same standard deviation, the position of the
graph shifted.

Figure 1.6 The position of the graph

26 PSP eBook | Quality Control - Topic 1

b) Same value of mean, but different standard deviation; causes the
graph to change in slope.

Figure 1.7 The slope change
Relationship between the standard deviation with the area under a normal
distribution graph.

Figure 1.8 The standard deviation with the area under a normal distribution graph.

▪ Calculation:

a. Use formula = − to determine the standard deviation.


b. Then use the normal distribution table (Area under the standard normal curve)

to find the percentage. For example, Z= - 1.76, then the area under the standard

normal curve (percentage) is 0.0392 (3.92%).

c. Negative values of Z may also be referred to the positive value of Z

in the table (+1.76). Area under the normal curve will return the value

of 0.9608 (96.08%), namely 100%- 3.92% using the negative table.

d. Reminder that the percentage (area under the standard normal curve) read from

the table is always referring from the left side of the graph to the right of the

graph.

PSP eBook | Quality Control - Topic 1 27

Figure 1.9 The Z Value
e. Then to find the percentage of a range, for example, between 1.3 cm to 2.7cm

with a mean = 2.0 cm, the percentage must be calculated by subtracting the area
under the graph, 2.7 and 1.3 with the help of formula Z.
f. It is important to have a proper sketch of the normal distribution curve to help
during the calculation. By marking the section to be calculated correctly, the
sketch could help to identify if the percentage obtained is logical or otherwise.
g. To do so, mark the left side of the line if the questions asked for percentage less
than the given value, xi. If the questions asked for percentage more than the
given value, mark the right side of the line. Mark the centre if the question
requested for percentage between two values.

Figure 1.10 The section marking
EXERCISE 1.1
1. Define the meaning of quality control. CLO1:C1 (2 marks)
2. Choose which type of inspection is most suitable for the following product

(100% inspection or sampling inspection) then explain in why:

28 PSP eBook | Quality Control - Topic 1

a. Missile for country defense use CLO1:C2 (10 marks)
b. Bullet for policemen use CLO1:C1 (8 marks)
c. Heart attack medicine
d. Tissue paper
e. Car braking system

3. Describe the concept of
i. Continuous improvement
ii. Quality assurance
iii. Statistical process control
iv. Total Quality Management

EXERCISE 1.2

Explain the following terms referring to MS ISO 9001:2008- Quality Management
Systems- Requirement

1. General documentation requirement
2. Control of documents
3. Quality management system planning
4. Responsibility and authority
5. Internal communication
6. Provision of resources
7. Design and development validation
8. Validation of process production and service provision
9. Customer satisfaction
10. Internal audit

CLO1:C1 (20 marks)

PSP eBook | Quality Control - Topic 1 29

EXERCISE 1.3

i. Data below shows the length of the steel rod sample produced by GRF

Sdn. Bhd in January in inches. Calculate the mean, standard deviation

and the range for this batch of product.

5.485 6.744 5.165 5.301 5.291

8.317 5.158 5.810 8.748 5.399

6.265 5.671 7.436 8.365 6.750

(Calculate all the value up to 4 decimal points)

CLO1:C2 (8 marks)

ii. Based on the finding from 1.3(i), assuming that the process is normally
distributed, calculate :
a. percentage of rod that is more than 9.000 inch.
b. percentage of rod that is less than 4.600 inch.
c. percentage of rod that is between 5.000 and 7.000 inch
(Calculate the Z value up to 3 decimal points and use interpolation method to
obtain accurate answer)
CLO1:C2 (12 marks)

vi PSP eBook | Quality Control - Topic 1

References

Besterfield, D. H (2004). Quality Control. Seventh Edition. Prentice Hall.
Kamsi, R. (2003) Student Workbooks Quality Control. Tg Dot Net.

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