Quality Control Era

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.


The inspection-based approach to quality was challenged by Walter A. Shewhart. Shewhart's landmark 1931 book Economic Control of Quality of Manufacturing introduced the modern era of quality management. In 1924, Shewhart was part of a group working at Western Electric's Inspection Engineering Department of Bell Laboratories. Other members of the group included Harold Dodge, Harry Romig, G.D. Edwards, and Joseph Juran, a veritable "who's who" of the modern quality movement.

The new concept of quality included ideas that were quite radical at the time. Shewhart recognized that variation could never be completely eliminated. Try as one might, no two things could ever be made exactly the same. Thus, he reasoned, attempts to eliminate variability were certain to fail. Then Shewhart took a huge conceptual leap: the central task of quality control was not to identify variation from requirements, it was to distinguish between variation that was a normal result of the process and variation that indicated trouble. This insight lead directly to Shewhart's now famous concept of statistical control.

The concept is explained by Shewhart as follows:

A phenomenon will be said to be controlled when, through the use of past experience, we can predict, at least within limits, how the phenomenon may be expected to vary in the future. Here it is understood that prediction means that we can state, at least approximately, the probability that the observed phenomenon will fall within the given limits.

Shewhart's approach to quality was to identify the limits of variation that could be expected from a process operating in a "normal" state. To do this he developed simple statistical and graphical tools that could be used to study data obtained from a process. Unlike inspection, Shewhart's approach did not require 100% inspection or sorting; samples could be used. Furthermore, as long as the process variability was less than the design required, one could be assured that acceptable process quality was being maintained. Shewhart's approach is known today as statistical process control, or SPC. SPC remains one of the quality professional's most powerful tools, in a form largely unchanged from Shewhart's original presentation.


Quality means fulfilling the customer's requirements and expectations, at all times. It is also important to bear in mind that quality standards must be set to meet legal requirements. As the customer's requirements are typically higher than legal ones, standards set by authorities should be regarded as minimum or bottom-line requirements.


A set of procedures taken to assure that a product manufactured or service delivered would meet defined quality requirements or customer's needs.


· Improvement in the quality of the product and the services

· Production improves

· The system is continually evaluated and modified to meet the changing needs of the customers

· Reduces cost in the long term

· The lead time for the producing parts and subassemblies reduces.


• A systematic method for transferring customer wants/needs/expectations into product and process characteristics

• Developed by Shigeru Mizuno (1910-1989) and Yoji Akao (b.1928) in Japan

• Excellent tool for communication between cross-functional groups

• Provides a common basis for

o Integrated Product Development

o Simultaneous Engineering

o Concurrent Engineering


“The simultaneous performance of product design and process design. Typically, concurrent engineering involves the formation of cross-functional teams. This allows engineers and managers of different disciplines to work together simultaneously in developing product and process design.”

• 3 Main Areas to Concurrent Engineering

1) People

2) Process

3) Technology


Managing Quality + Time + Productivity + Capacity = JIT

The objective of JIT is to . . .

• purchase materials

• produce products

• and deliver products

. . . just when they are needed


Voluntary groups of employees who work on similar tasks or share an area of responsibility

• They agree to meet on a regular basis to discuss & solve problems related to work.

• They operate on the principle that employee participation in decision-making and problem-solving improves the quality of work

How Do Quality Circles Work

• Characteristics

- Volunteers

- Set Rules and Priorities

- Decisions made by group

- Use of organized approaches to Problem-Solving

• All members of a Circle need to receive training

• Members need to be empowered

• Members need to have the support of Senior Management


It means identifying the likely causes of a problem thoroughly. Their major benefit is that they push to consider all possible causes of the problem.

Suggested steps for conducting Cause & Effect Analysis

· Identification of a problem

Pen down the exact problem faced in details.

· Identify who are involved, what is the problem and when and where it occurs.

· Workout the major factors involved

· Identify the factors that cause the problems.

· Draw lines off the spine for each factor and label it.


Total Quality Management means that

· the organization's culture is defined by and supports the constant attainment of customer satisfaction through an

· integrated system of tools,

· techniques, and training.

This involves the continuous improvement of organizational processes, resulting in high quality products and services.

The three aspects of TQM

· Counting

Tools, techniques, and training in their use for analyzing, understanding, and solving quality problems.

· Customers

Quality for the customer as a driving force and central concern.

· Culture

Shared values and beliefs, expressed by leaders, that define and support quality.

Total Quality Management and Continuous Improvement

· TQM is the management process used to make continuous improvements to all functions.

· TQM represents an ongoing, continuous commitment to improvement.

· The foundation of total quality is a management philosophy that supports meeting customer requirements through continuous improvement.

Value-based Approach

u Manufacturing Dimensions

• Performance

• Features

• Reliability

• Conformance

• Durability

• Serviceability

• Aesthetics

• Perceived quality

u Service Dimensions

• Reliability

• Responsiveness

• Assurance

• Empathy

• Tangibles

Four Levels of Quality

· FITNESS FOR STANDARD -inspection oriented -no consciousness to customer/market

· FITNESS FOR USE -Must satisfy customer need for use -Hotel shampoo & body oil

· FITNESS FOR MARKET -Must achieve low cost as well as 1 & 2

· FITNESS FOR LATENT REQ'TS -Listening to the voice of the customer -V-8 engine, Swatch -Uncovering latent req'ts adds value

==> need continuous innovation


· Create constancy of purpose for improvement of product and service.

· Adopt the new philosophy --poor quality cannot be tolerated.

· Cease dependence on inspection to achieve quality.

· End the practice of awarding contracts on the price tag alone; work with a single supplier.

· Improve constantly and forever every process for planning, production, and service.

· Institute training on the job.

· Adopt and institute leadership.

· Drive out fear.

· Break down barriers among staff areas.

· Eliminate slogans, exhortations , and targets for workers.

· Eliminate numerical quotas for the workforce and numerical goals for management.

· Remove barriers that rob people of their pride of workmanship. Eliminate the annual rating or merit system.

· Institute a vigorous program of education and self-improvement for everyone.

· Put everybody in the company to work to accomplish the transformation.


Statistical quality control technique, where a random sample is taken from a lot, and upon the results of the sample taken the lot will either be rejected or accepted.

Accept lot

Ready for customers

Reject lot

Not suitable for customers

Statistical process control

determine if in acceptable limits


Determine the quality level of an incoming shipment or, at the end production

Ensure that the quality level is within the level that has been predetermined


· Total Productive Maintenance (TPM) is an approach to managing physical assets that emphasizes the importance of operator involvement in making equipment reliable

· Management has always held an operator accountable for production output. More than ever, that person is also responsible now for product quality

· Many factors affect how well that can be achieved, including the way in which the workplace is organized as well as the equipment's effectiveness. When several people are involved, producing quality depends on teamwork

The prime objectives of TPM are to:

· Maximize equipment effectiveness and productivity and eliminate all machine losses

· Create a sense of ownership in equipment operators through a program of training and involvement

· Promote continuous improvement through small-group activities involving production, engineering, and maintenance personnel


• Method of prioritizing problems or causes by frequency of occurrence or cost

• Based in the 80-20 rule:

• 80% of the problem is caused by 20% of the sources

• “Vital few” and “trivial many”

• Depicted by a vertical bar graph arranged from left to right descending order

Advantages of a Pareto Chart

• Focuses efforts on problems with greatest potential for improvement

• Distinguishes the critical causes from the less significant causes

• Helps prevent “shifting the problem” where the solution removes some causes but worsens others

· Measure the impact of improvement projects when comparing charts “before” and “after”

• The chart shows the relative importance of problems in a simple, quickly interpreted, visual format.

• Progress is measured in a highly visible format that provides incentive to push on for more improvement.



•Challenge of identifying best practices

•Overuse of statistical tools/ under use of practical knowledge

•Challenge of developing hypotheses


•Challenge of developing ideas to remove root causes

•Difficulty of implementing solutions

• Control

•Lack of follow up by Managers/ Process Owners

•Lack of continuous Voice of the Customer feedback

•Failure to institutionalize continuous improvement.

Benefits of Six Sigma

•Generates sustained success

•Sets performance goal for everyone

•Enhances value for customers;

•Accelerates rate of improvement;

•Promotes learning across boundaries;

•Executes strategic change