Introduction
Most of the time, chronic manufacturing problems are ignored if their effect is tolerable. Only after the effect of a manufacturing problem spikes are the problems recognized and addressed. It would be a manager’s Nirvana to have a magic wand to cause these aggravating problems to disappear. Unfortunately, the “wizardry” needed to systematically identify, study, and solve problems has not been achieved by the people most responsible for managing and solving industrial problems.
Process improvement is an ongoing activity that should be applied whenever your company learns a new lesson. The examples and illustrations in this book originate from the experience I gained working with more than 200 individual suppliers while in high-volume manufacturing facilities. When any discrepant condition affecting the process was identified, I included it in the body of the correction process with an assigned corrective action. This was done to prevent recurrences. These items were then systematically added to the Design Failure Modes and Effect Analysis (DFMEA) or Process Failure Modes and Effect Analysis (PFMEA),1 and in the control plans2 for current and future products.
These techniques have been applied effectively in the United States, Canada, Italy, Hong Kong, and China, and in facilities that manufactured toys, chemicals, electronics, castings, strollers, adolescent clothing, gears, engines, and other machined or assembled components. The processes used to detect and solve problems can be used anywhere to expedite industrial problem-solving resolutions.
Results of “common knowledge” methods depend upon the skills and training of the individual involved. Many individuals have not been trained in effective problem-solving techniques. A formal education allows you to develop cognitive skills, but does little to establish an efficient roadmap for guide those thrown into the problem-solving battle.
I wrote this book to provide a simple map that can help anyone transform difficult technical problems into easily solved ones. The method involves applying creative steps to improve understanding while using the tools available. These tools enable those unfamiliar with a manufacturing process to attack problems, even when they don’t fully understand the fundamentals of that process.
Some organizations have never attempted to improve efficiency, and therefore profits, by using a system to identify problems. As a result, unidentified problems may and probably have caused a significant reduction in bottom-line results. Therefore, applying corrective actions to eliminate unaddressed underlying quality problems will boost profits.
A Time-Tested Problem-Solving Technique
These six actions are necessary to scrutinize and resolve recognized problems:
Define the specific problem and condition (the characteristics or physical appearance of the subject) thoroughly. Evaluate problems by the dollar loss that they generate.
Verify that the process is operating as intended and specified. Conduct a review of the control plan and the operating procedures to ensure that the process is being managed as desired.
Observe the operation for detrimental or ruinous conditions. Determine if there is anything specific causing distress in the process.
Develop a check system for recognized manufacturing control items. Decide what is important to control so that the process is acceptable.
Conduct checks with more than one layer of inspection. Two or more people should conduct the checks individually.
React to the conditions that must be corrected or improved. Add corrective actions to the audit list if any item or condition is found that has or will have a negative effect on the process or the product.
Each of the six steps is discussed throughout the book. If these actions are used in conjunction with established, consistent work instructions, they will be instrumental in preventing errors, losses (scrap, rework, lost production, and so on), and decreases in customer satisfaction. However, this is only the beginning of the correction process. Customer expectations must also be fulfilled in order to increase future demand and profits. Consequently, any expectation not fulfilled may affect customer satisfaction and may adversely affect future profitability.
These steps are applicable to small as well as difficult problems. The methods I use to illustrate them include actual manufacturing examples and conditions, which provides relevance and clarity for understanding. When you use these practices, you can expect improved operations and profit. This is true whether the manager has professional problem-solving experience or not.
Roadmap to the Book
Although some of these tools are used in industry, the quality of their results depends on the individual using them. The following pages illustrate the power inherent in successful problem-solving techniques and provide the information you need to use them effectively.
Examples provide insight into the nature and use of steps available to achieve problem-solving effectiveness. They will help the novice or expert problem-solver alike.
Note You do not have to understand statistical methods and statistical analysis to apply the tools described in this book. The steps and tools can be easily applied to technical or service problems. In addition, you will find that they become easier to use with each application.
Some of the verbiage used in this book may not be familiar to you. These include acronyms and terms like FMEA, consistent work, job instructions, variable gauges, sporadic incidence, plan of attack, calibration, foreign material (FM), interaction, and concept diagram. Seeing these terms in context may be sufficient for understanding, but if they’re still unclear, refer to Appendix F, “Definitions.”
When you’re faced with a problem, you normally compare five good and five bad samples to generate clues. But due to the need for simplicity, photograph clarity, and the necessary size of image display, I have reduced the sample size to three good and three bad in most cases. This reduced sample size still provides clarity for understanding. (See Appendix E, “Sum of Extremes Test,” for the rationale used for this comparison.)
The contents follow a plan that provides you with the steps necessary to evaluate any problem. These actions begin with:
Chapter 1: Define the Problem (Step One). This chapter introduces you to the concept that you can evaluate and explain any problem if it’s understood thoroughly. If you observe and define part characteristics adequately, it is easier to surmise the conditions that may have caused the characteristic. Further, the chapter introduces methods for collecting data and applying available tools to evaluate current problems.
Chapter 2: Define Fault Characteristics (Step Two). This chapter explains the methods for understanding the problem defect or condition by determining the characteristics that may be causing problems. You’ll read about considerations that are useful in identifying problems, including defect scene characteristics and contrasts of two, both of which aid future analysis.
Chapter 3: Construct a Concept Sheet (Step Three). This chapter introduces the use of concept sheets, which list any conditions suspected to cause the detrimental condition. Case studies in welding, leaking, and broken component problems illustrate how to use concept sheets. You’ll also become more proficient in using them over time.
Chapter 4: Develop a Plan of Attack (Step Four). This chapter identifies a method for moving toward a solution. It introduces the concept of interactions, which can adversely affect processes. Sketches and photographs illustrate problems that I have experienced and resolved. This chapters also explains how to collect and compare samples whenever a problem arises.
Chapter 5: Collect Relevant Data (Step Five). This chapter describes the types of data that you can collect. It differentiates between causative and quantifiable data and explains how to use both in rectifying problems. It explains how to use a visual rating system when numerical data can’t be collected easily or at all. It also provides examples of constructing visual systems so that you can understand the difference between good and bad part criteria.
Chapter 6: Generate Clues (an Interlude). Although not one of the formal eight steps, this chapter contains other problem-solving tools useful for generating clues. It summarizes numerous tools I have used successfully with past problems. The chapter also describes tests with examples you can use to generate clues. These are the sum of extremes, duos, data ranking, and good versus bad comparisons, all of which you can use to generate clues or to verify that corrective actions were satisfactory.
Chapter 7: Choose and Use Analysis Tools (Step Six). This chapter introduces innovative tools to aid you in resolving problems. It proposes generating visual clues about how a component passes through a system with more than one flow path. It also introduces the use of other tools, such as the noise matrix layout and the cracked-and-broken worksheet.
Chapter 8: Use Innovative Analysis Tools (Step Seven). You may not be familiar with some of the tools that are presented in this chapter. You can augment the use of consistent work and review lists by creating visual comparison systems to attack your problem. These include flow charts, matrix applications, and a cracked-and-broken worksheet.
Chapter 9: Establish Consistent Work and Many-Level Reviews (Step Eight). This chapter explains the methods to use to prevent future problems once a system or specific problem has been rectified. It proposes the use of check sheets to prevent conditions from slipping out of control. It also provides a mixed-part check sheet, which will serve as a guide for preventing future problems and managing problem-resolution activity. Last, it recommends that any important manufacturing responsibility be assigned to an advocate.
Chapter 10: Summary. This chapter ties everything together with a few handy lists.
There are also six appendixes, which contain more information on processes, the basis for decisions, various tests, more complicated examples, and definitions.
This book is full of examples of actual methods I have employed to determine solutions to problems. The discussion is keyed in to illustrations where possible, because they clarify the methods employed.
The book also shows you examples that you can apply to similar circumstances. It will increase your perceptions in dealing with manufacturing problems and, hopefully, aid you in becoming a manufacturing or service problem-solving expert.
I only wish that this information had been available in a course during my engineering or technical training; it could have saved me years of problem-solving effort.
1The DFMEA defines the design considerations that will be applied to a product, whereas a PFMEA relates to the process you use to ensure you obtain the desired engineering and aesthetic results.
2A control plan is a specified method for organizing and managing a manufacturing or service process.