Problem Solving Methodology for PCB Designers

| Created: March 24, 2019 | Updated: April 15, 2020

One of the skills that is useful when working in a high-technology industry like electronics is problem- solving. If you are an engineer, then this is one of your key focuses in your career. Even if you are not, having good problem-solving skills is always useful.

In electronics manufacturing today, problems in production will involve numerous ‘cause-factors’, many of which are design created. PCB designer communication is essential. The timing of this communication depends on how quickly the manufacturer is expected to correct the issue. Feedback should be specific and detailed, with supporting evidence such as photographs and test results if available. The fabricator or assembler will have this information after an investigation of root cause and develop a corrective action plan.

For serious quality problems that generate scrap or rework, customers will insist that the manufacturer submit a written document that describes the investigation and corrective actions, or a corrective action report (CAR). The purpose of the document is to provide a record of the problem-solving and establish confidence that the manufacturer has successfully addressed the issue and that the issue will not recur.

The Problem-Solving Process

When selecting a problem-solving process, it is important to understand when you should—and should not—use structured problem-solving. Therefore, an understanding of problem-solving methodology is crucial. Once you have selected a process to use, be sure to document and communicate progress throughout the project.

One of the major problem-solving methodologies is the TQC PDCA Process: Plan—Do—Check—Act. Also, the six-sigma DMAIC process: Define—Measure—Analyze—Improve—Control. Familiar to many of you would be the general scientific method:

Define the question/make observations
Gather information and facts
Form hypothesis
Perform experiments and collect data
Analyze data
Interpret data and draw conclusions
Summarize results

A common methodology used by many manufacturers is ‘Eight Disciplines Problem Solving’ (8D), created by the U.S. Department of Defense and popularized by Ford (Table 1).

STEP	PURPOSE	OUTPUT	KEY QUESTIONS
1. Define Problem	Identify the problem and the importance of working on it. Usually, a short title that best describes the problem.	• Problem statement • Project owner • Business priority • Stakeholders (customers, suppliers, team members)	• What is the problem or gap to be addressed? • Why is this a customer/business priority? • Who are the key players associated with the project? • Estimated resources (people, time, money)? • What are containment activities for customers?
2. Current Situation	Clarify the problem area(s) as the situation exists today. Describe what is known about the problem.	• Identification of where the problem is or is-not • Supporting information to help focus on the root cause analysis	• What data do you have about the problem? • Are there trends in this data (TQC 7-tools, statistics)? • Is there other data that you need (process flow diagram)? • What key areas does the data tell you to focus on?
3. Cause Analysis	Identify and verify the root causes of the problem/ situation.	• Cause/effect of the problem • Determine what caused(s) the problem • Data and analysis verifying root cause	• Why is the problem occurring (cause & effect diagram)? • What are the possible root causes based on data collected and analyzed in Step 2? • What causes have the greatest impact on the problem (why)? • Use analysis tools to evaluate data (TQC, DOA)
4. Solutions	Develop plans to eliminate the root cause of the problem/situation.	• Documentation of proposed solutions which eliminate causes • Plan for implementing and monitoring results • Performance against schedule (PAS) for plan implementation	• What possible solutions would eliminate the causes identified in Step 3? • What are the recommended solutions? • Who is impacted by the solutions? • What is the implementation plan? • What monitors have been established to measure improvements?
5. Check Results	Implement plans, confirm they have impacted the root causes and that goals for improvement have been met.	• Data confirming that the solutions eliminated the root causes • Decision on whether to standardize the improvement	• To what extent have the solutions eliminated the root causes (TQC tools, DOE)? • Have the desired goals been achieved (from Step 1)? • Were there deviations from the planned improvement? • Should the improvements be standardized?
6. Standardization	Modify the process/system to ensure that the improvements are sustained over time.	• Documented plan for communicating, integrating and monitoring the change • Implementation of the plan	• What does the new process look like (process flow)? • How will you integrate changes into the organization? • Monitor the performance of the process to ensure the problems are not recurring.
7. Future Plans	Evaluate where we have been and where we need to go.	• Data and documentation showing the effect of the improvement effort • Summary of remaining problems and a plan for addressing them	• To what extent did the solution improve the problem? • Does the problem require further investigation? • What issues were uncovered during problem-solving? • What other areas should the process changes be applied to? • What did the team learn during the problem-solving? • Celebrate the team’s success

Table 1. 8-Step Problem Resolution Process [source: Ford Motor Co.]

My favorite is the problem-solving methodology that is taught by Kepner-Tregoe [1]. This is a rigorous three-day course, usually referred to as KT, which has expanded the problem-solving processes into four areas: Situation Appraisal—Problem Analysis—Decision Analysis—Potential Problem Analysis (Figure 1). Its three action sequences (Figure 2) summarize the important steps in the KT process.

All these processes emphasize the need to understand why the issue is occurring under one set of circumstances but not another, and to consider more than one possible root cause. Regardless of which process is used, the customer should require a systematic approach to problem-solving from the manufacturer to avoid these pitfalls:

Poorly defined and characterized problem
Rapid convergence on a single root cause without considering others
Confusion about who is working on the resolution
Failure to segregate suspect material
Poor verification of root cause or solution
No schedule to track deliverables for verification
No leverage of knowledge or defects discovered on similar products

Figure 1: Kepner-Tregoe Problem Solving Process^©^®. [source: Kepner-Tregoe]

There is often some urgency to find and resolve the issue, and the sourcing team should be wary of quick solutions proposed by the supplier without thorough analysis. The supplier may propose additional testing and inspection on their side to check for defects and prevent future escapes, but the sourcing team should push for permanent process changes to prevent defects from occurring in the first place. Finally, the corrective action request should not be considered closed until improvement has been measured and noted by the customer. A corrective action plan is not the same thing as the successful implementation of that plan.

Figure 2: Kepner-Tregoe Problem Action Sequence^©^® . [source: Kepner-Tregoe].

Further reading and resources is the ASQ, American Society for Quality [2] . Villanova University has a number of online six-sigma and Agile courses and certificates [3].

Would you like to find out more about how Altium can help you with your next PCB design? Talk to an expert at Altium or read more about how Altium Designer^® can help you simulate and validate your designs.

References

Kepner-Tregoe: www.kepner-tregoe.com
ASQ: www.asq.org
Villa Nova University; www.villanovau.com

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About Author

Happy Holden is retired from GENTEX Corporation (one of the U.S.'s largest automotive electronics OEM. He was the Chief Technical Officer for the world’s biggest PCB Fabricator-HonHai Precision Industries (Foxconn) in China. Prior to Foxconn, Mr. Holden was the Senior PCB Technologist for Mentor Graphics; he was the Advanced Technology Manager at NanYa/Westwood Associates and Merix Corporations. He retired from Hewlett-Packard after over 28 years. His prior assignments had been as director of PCB R&D and Manufacturing Engineering Manager. While at HP, he managed PCB design, PCB partnerships, and automation software in Taiwan and Hong Kong. Happy has been involved in advanced PCB technologies for over 47 years. He has published chapters on HDI technology in 4 books, as well as his own book, the HDI Handbook, available as a free e-Book at http://hdihandbook.com and de recently completed the 7th Edition of McGraw-Hill's PC Handbook with Clyde Coombs.