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A Formal Problem Solving Methodology is not just 6 Sigma

We know that the implementation of Lean Methodologies helps the organization to identify and eliminate waste and in the world of Lean there is a suite of tools and methodologies that can be utilized depending on the situation.

Many organizations fixate on just one formal problem solving methodology thinking that it will be the silver bullet to kill all problems. However it normally better to have a suite of formal problem solving tools that can complement each other.

If we view problems as opportunities that are causing variation within our process we need to categorize the variations and use the proper methodology.

In order to differentiate between Problem Solving Methodologies available, a definition of problem types is required;

Common Cause

A problem requiring fundamental improvement to correct (ie. reduce variation). Defined by the observation that it has always been that way (substandard). These types of problems are Engineering or Continuous Improvement based (ie. Scrap reduction, Capability Improvement)

They are not characterized by an abrupt change from one state (acceptable) to a new state (unacceptable).

Special Cause

A problem that by its very definition causes us to ask the question : What Changed? It is signified by the realization that what was once acceptable has become unacceptable. The goal of solving is generally to allow us to return to our previous state of operation – quickly and prevent further loss due to the diminished state of operation.

Objectives for a Formal Problem Solving Approach

Goal : Identify, Train, Implement a practical operational level problem solving tool that is simple, robust and generic.

Criteria :

1) The tool must be instinctive for use by all factions of the operation to resolve problems

2) Tool must be effective for Processes, Set-up issues, System, Tooling, Operating Systems, ISO violations, New Product Launch

Measures :

1) Resolves chronic problems

2) Timely in resolution weeks vs. months

3) Reduction in scrap and rework

4) Reduction in operating system violations

All types of problems require quick resolution. However, certain tools and skills are more effective than others at solving specific types of problems.

Problems … Problems … Problems ...

As you can tell from the chart below there are several methodologies … some which take a long time for training and to embed into the organizational culture … which is why many organizations fail with 6 Sigma.

Technical : Product/Process not Capable, Excessive Scrap Level, Process not Stable, Set-up difficult/inconsistent, Customer Dissatisfied

Operational : Throughput, Downtime, Maintenance, Reliability

Organizational : Strategic, Human Resource, Administrative inefficiencies

The following is a brief outline of the various Problem Solving Methodologies :

Kepner - Tregoe - Problem Solving & Decision Making (PSDM)

- KT approach is a thorough fact finding and information organizing process that points towards the root cause of Special Cause Problems. It is most effective when a condition was acceptable, and has subsequently become unacceptable (ie. a Deviation has occurred).

- Utilizes a specific framework to follow from problem definition through to confirmation of root cause.

- Problem Description is cornerstone of process. Utilizing specific questions to define what the problem is and is not. Provides a clear understanding of the issue. These facts are later utilized to validate the potential root cause(s) through evaluation of distinctions and changes.

- Potential causes are measured against the known facts (IS/IS NOT statements). Root cause must be able to adequately explain the facts as they are actually observed. Most likely cause(s) are then validated and corrective measures taken.

- PSDM can be installed in an organization through a Train the Trainer approach. This ensures that the cost is minimized without compromising the integrity of the training. Case studies and action learning are the model for the training program.

- KT allows an organization to speak the same language about Problem Solving, and look at problems analytically without jumping to conclusions. Ensures that the Cause is identified, not only the symptoms of a problem, and ensures that any implementations consider potential side-effects prior to launching so that contingency plans can be developed to protect the desired outcomes.

5 Why

The 5 Whys is a technique that doesn't involve data segmentation, hypothesis testing, regression or other advanced statistical tools, and in many cases can be completed without a data collection plan. By repeatedly asking the question "Why" at least five times, you can peel away the layers of symptoms which can lead to the root cause of a problem.

Here is a simple example of applying the 5 Why's to determine the root cause of a problem. Let's suppose that you received a large number of customer returns for a particular product.

Let's attack this problem using the five why's:

1. Why are the customers returning the product?

Answer: 90% of the returns are for dents in the control panel.

2. Why are there dents in the control panel?

Answer: The control panels are inspected as part of the shipping process. hus, they must be damaged during shipping.

3. Why are they damaged in shipment?

Answer: Because they are not packed to the packaging specification.

4. Why are they not being packed per the packaging spec?

Answer: Because shipping does not have the packaging spec.

5. Why doesn't shipping have the packaging spec?

Answer: Because it is not part of the normal product release process to furnish shipping with any specifications.

Using the five why's in this case revealed that a flaw in the product release process resulted in customers' returning of a product.

Toyota A3

Hate to break it to you ... but quite simply an A3 is just a summary document of either your problem solving investigation or project update but the information always flows in the same general manner.

Shainin (Statistical Engineering)

- Utilizes the “SWAT” Team approach, small highly focused unit actively engaged in finding a solution to a particular problem. Two stage process : Diagnostic Journey, and Remedial Journey.

- Diagnostic Journey begins with an effective measurement system to assess the output variable (Green “Y”) that defines the problem. (Utilizes a tool called an ISOPLOT)

- Formulates a Solution Tree to define the families of variation present in the problem (Families include part to part, time to time, within part). Expands families of variation to include how potential causes could influence variation observed in the product.

- Utilizes Clue Generation tools such as Multi-Vary to expose the nature of the variation (ie. how it manifests itself over time). Involves the measurement of a specific quantity of parts in a specific manner, at a specific time interval to determine which family of variation is dominant.

- Formulates a Designed Experiment to determine the effect of potential causes of variation on the Green “Y”. Utilizes the Pareto principle that states that for a particular problem there is usually a primary contributor or “Red X”. Lesser variables that have a measurable effect are termed Pink X, Pale Pink X etc… These are not ignored but considered subordinate to the Red X. Once Red X is found, the diagnostic journey ends and the remedial journey begins.

- Remedial Journey utilizes a Designed Experiment to construct a Tolerance Parallelogram for the Red X. This defines allowable limits that the Red X can run within in order to ensure that the Green Y remains in control.

- Locks in the gains by utilizing Pre-Control methodology to lock in the Red X variable and prevent the problem from recurring (process controls vs product controls).

- Looks beyond the fix to other systems or parts that could benefit from this new knowledge.

- Most effective on Product/Process Capability (ie. variation reduction) projects to expose and correct common causes of variation in a manufacturing process.

Six Sigma

- Six Sigma is associated with Six Sigma levels of process capability (ie. 3.4 defects per million opportunities to create a defect).

- Developed in the 1980’s by Motorola as a mandate from their CEO to reduce rising warranty and manufacturing costs. The basis of the program is that any project undertaken will reduce variation within any process such that there are less than 4 mistakes per million process outputs.

- Projects are submitted for senior management review and approval. All projects must have a direct positive effect on the bottom line with usual cost reduction greater than $250,000.

- The tools in the Six Sigma toolbox are not new, they are a combination of quality, engineering and statistical tools that have been used by manufacturing people over the last 100 years.

Common terms in a Six Sigma organization are:

- Master Black Belt: Person who has successfully led Six Sigma teams on process variation reduction projects. This person has extensive knowledge and has become proficient in use of the tools of Six Sigma. Teams consult this individual on project clarification. The Master Black Belt is a teacher in the Six Sigma system. (ASQ is currently developing a Master Black Belt Certification program to ensure those people using this title are qualified.)

- Black Belt: Person who is trained in the use of the tools and leads project teams through the Define, Measure, Analyze, Improve and Control phases. They are the tool mentors and change agents leading Breakthrough Projects and coaching Green Belts.

- Green Belts: Project team members who gather and analyze data, develop improvement methods. Apply Six Sigma tools within the context of their own jobs.


• Triz is a Russian acronym for The Theory of Inventive Problem Solving. Process was developed through analyzing over 1,500,000 patents and determining the engineering principles that led to the invention.

• The Triz Practitioner will undertake solving problems that have NO known solution. The table below shows the conceptual theory behind Triz. There are numerous laws and hypothesis developed by Triz and extensive training is required to understand their usage.


There is a wide array of formal problem solving tools to learn. In many cases the basic ones still need a kernel of a problem solving methodology to be embedded within a formal problem resolution process like 8D or an A3.

Also co-mingling many of the methodologies within your organization will allow for a problem to be escalated until it becomes resolved permanently. For example you can use an A3 to resolve a special cause problem or use it to frame what the problem may be. The output of this, if the problem is not resolved can become the inputs for Kepner-Tregoe Problem Solving exercise and if this still does not resolve the problem since more data is required then it becomes a good candidate for Six Sigma.


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