Preface

What do we mean by quality products, quality design, and quality improvement? Do we mean

• Fitness for function?

• Customer satisfaction?

• Conformance to design specifications?

• Conformance to requirements?

• Providing products and services that meet customer expectations over the life of the product or service at a cost that represents customer value?

While most of these words sound fine, such definitions have not been very useful in helping us do a better job. Why? Because they are attribute-based. A precise quantitative definition has not been established. In general, they prescribe that something is either in one state or another:

• Good or bad.

• Fine or not fine.

• Defective or nondefective.

• Conforming or nonconforming.

As a result, such definitions are serious inhibitors to continual and never-ending improvement. They are product-based (attribute-based) and comparative—that is, they attempt to compare the product, upon completion of manufacturing, to the input specifications of the manufacturers. As a result, they become static and passive filters through which we attempt to push product. They cannot serve as design criteria. They do not clearly distinguish between product species and product function. Species is a matter of subjective criteria (i.e., color, style, customer preference). Function, on the other hand, is a matter of loss of performance in use (i.e., useful life, power consumption, trouble in field, harmful effects, user friendliness).

A product is sold (gains market) by virtue of its species, function, and price. A product gains or loses reputation (market share) by virtue of its quality. Therefore, quality must be judged through customer loss, as a result of functional variation and harmful effects, when the product is used. Functional variation is the deviation of performance from that intended by engineering design. Harmful effects, on the other hand, are injurious effects encountered during use, which are unrelated to function. For example, if the product is a train that can go 100 miles an hour, and the function is to reduce travel time, the harmful effect might be an uncomfortable ride due to excessive vibration.

Functional variation is manifested in two basic ways:

• Failure to meet the target (average performance).

• Variability of the target (dispersion performance).

This means that the focus in any process is to be on target with the smallest variation. So, the greatest difficulty we have with the meaning of quality centers around our inability to define it in precise and quantitative terms that can then be used as design criteria rather than simply as shipping criteria.

We therefore cannot afford to use concepts and measures of quality that:

• Do not relate the achievement of quality to the engineering design process as a criterion.

• Administer "quality control" through defect detection and containment (i.e., product control).

• Promote improvement only to some acceptable plateau of performance.

• Inhibit the continual pursuit of never ending improvement.

• Have a weak and perhaps an opposing relationship to performance in terms of productivity.

• Have a producer rather than a consumer orientation.

There is a very strong relationship between quality and productivity. Adding improvement building blocks to an ideal industrial system in any arena is possible on an appropriate and sound foundation. Competitive pressures have recently caused many companies to examine the foundations on which their improvement strategies are based.

A competitive position in the marketplace, for both manufacturing and non-manufacturing companies, depends then on two components: quality and productivity. Any improvement strategy should accordingly aim for maximum advancement within these two components and progress may be measured by monitoring such advancements.

For a company to improve its long-term competitive position, it must focus on the process rather than on the product. Appropriately applied, the concepts and techniques embraced by the six sigma methodology help companies to maintain this focus and provide guidance for quality and productivity improvement.

The trilogy balance that, guides the six sigma methodology to the improvement levels of 3.4 defects per million are the strategies of technology, people and business. Focusing on any one in particular shifts the balance and suboptimization will occur to the detriment of the entire organization.

This book focuses on the basics of the six sigma methodology. It covers the essential items and selected tools for pursuing excellence without getting bogged down with details. Specifically, on a chapter basis it discusses the following:

• Chapter 1: Overview of six sigma. The focus of this chapter is the essential core elements of the six sigma methodology. The chapter outlines what six sigma is and what the key questions or concerns surrounding it are.

• Chapter 2: Customer satisfaction. This is the cornerstone of every quality initiative. The aim of this chapter is to clearly explain why customer satisfaction is important and how it relates to six sigma.

• Chapter 3: The DMAIC model. This is the core model of six sigma. This chapter explains the process and requirements of this traditional approach to six sigma.

• Chapter 4: Common methodologies (tools) used in the DMAIC model. This chapter provides a selected review of tools and methodologies used in the DMAIC model for optimizing customer satisfaction and profitability.

• Chapter 5: Design for six sigma. This chapter explains the DCOV model, which is a much more powerful approach than the DMAIC model. It also addresses the process and requirements associated with this approach.

• Chapter 6: Common methodologies (tools) used in the DCOV model. This chapter reviews the tools and methodologies used in the DCOV approach for optimizing customer satisfaction and profitability in the design phase of product and service development.

• Chapter 7: Roles and responsibilities. This chapter explains who does what, and where they do it. The focus is to summarize the roles and responsibilities of the people directly involved with the six sigma methodology.

• Chapter 8: Six sigma applied in non-manufacturing. This chapter discusses the essentials of the non-manufacturing application of six sigma. Addressing the issues and concerns of non-manufacturing in a transactional environment (i.e., businesses that focus on services other than manufacturing—for example, financial, consulting, or engineering firms). An introduction to safety and environmental issues as they relate to how six sigma is also presented.

• Chapter 9: Training and certification. The aim of this chapter is to address the issues and concerns of training and certification for six sigma and explain the significance of both.

• Chapter 10: Implementing six sigma. This chapter outlines the change process from a traditional organization to a six sigma organization and examines the problems that may be experienced during the implementation process.

The accompanying CD provides the reader with a typical calculation for six sigma capability, a cascading model for identifying the customer's wants, and typical forms that may be used in the course of the six sigma implementation process. These items are of importance to the reader as they provide a cursory view of what it means to have the wants of the customer cascaded to develop the CTCs (critical to customer characteristics).

In addition, the CD includes a glossary of terms and more than 70 forms and tables that the reader may use in the process of developing the six sigma implementation process for their own organization. The forms vary from simple work sheets defining the function, to FMEA forms, to P-diagrams, gage capability and many more.