The Matrix is Real

A tool that I find extremely useful working in continuous improvement is the matrix.  The matrix can be used in many different situations to help discover relationships between various aspects of a process. There are numerous types of matrices to use depending upon your situation.  Do a web search for “Matrix” and see what’s out there.  But for now, here are a couple of my favorites. 

Cause & Effect Matrix

The first situation that I may use a matrix is in the measure phase of a Lean Six Sigma project. The matrix of choice is the Cause & Effect Matrix. The C&E Matrix helps determine the importance of key process inputs relative to the key customer requirements for the process.  The matrix allows for a less emotional and more consistent way to determine these relationships.

Developing a Cause and Effect Matrix

1. List the customer requirements
2. Determine the relative weight of each customer requirements
• 1 – less important
• 10 – more important
3. List high level process steps and inputs the inputs associated with each
• I typically acquire this information directly from a process SIPOC
4. Establish a scale to relate process inputs to the customer requirements
• Typically a 0, 1, 3, 9 stratification technique is used, where 0 is no relationship and 9 is a strong relationship
5. Relate each process step and associated input to each customer requirement
6. Calculate the score for each input
• For each individual input, multiply the relationship value in step 4 to the relative weight in step 2.  Add the multiplied values for each customer requirement for the input.
7. Order input score from high to low value
8. Establish a cutoff value
• Typically use a pareto for this.
• Above the value, the input remains for further analysis
• Below the value, it may go immediately unless there is a strong reason to keep the input

Figure 1 shows an example Cause & Effect Matrix

Solution Prioritization Matrix

Another situation I find a matrix to be useful is in solution selection during the improve phase of a project. The matrix I would use at this point is the Solution Prioritization Matrix. The Solution Prioritization Matrix can help prioritize potential solutions by determining how each potential solution may relate to the desired project outcomes.  I won’t go into the details of creation, as it is very similar to the creation of the Cause & Effect Matrix.  

Figure 2 contains an example Solution Prioritization Matrix.

Relative Weighting of Results	10	6	7	3	4
Desired Outcome	Operating Income	Impact on Cycle Time	Quality	Time to Implement	Ease to Implement	Total (Cross-Multiply)
Ideas
Idea A	3	9	1	0	9	127
Idea C	9	3	0	3	1	121
Idea B	9	0	1	3	3	118
Idea F	0	0	3	9	9	84
Idea D	1	3	1	9	1	66
Idea E	1	1	3	3	3	58

Let me know where you have used matrices to help make decisions.