Purpose: Compare two or more groups of ideas, determine relationships among the elements, and make decisions.
The matrix diagram helps prioritize tasks or issues in ways that aid decision making; identify the connecting points between large groups of characteristics, functions, and tasks; or show the ranking or priority of in an interaction.
Combined with tree diagrams, prioritization matrices can rank various choices in terms of impact on the customer, reduction in cycle time, defects, costs, and so on.
Matrices can be used in many ways to show relationships. They can be shaped like an L, a T, an X, or a three-dimensional, inverted Y. The L-shaped matrix helps display relationships among any two different groups of people, processes, materials, machines, or environmental factors. The T-shaped diagram is simply two L-shaped diagrams connected together showing the relationships of two different factors to a common third one. The Y-shaped matrix helps identify interactions among three different factors. The X-shaped matrix (two T¹s back to back) is occasionally useful.
- Generate two or more sets of characteristics to be compared. Use tree diagrams or brainstorming.
- Choose the proper matrix to represent the interactions (L, T, X, Y).
- Put the characteristics on the axes of the matrix.
- Rank the interactions from 1 (low) to 5 (high)