FACILITATOR TOOL KIT
an application acceptance process. For a complete description of cause and effect diagramming, refer to The Memory Jogger (GOAL/QPC, 1994). People
Application Acceptance Process
Process
Policy/ Procedure
Plant
Figure 14. Cause and Effect Diagram
Interrelationship Diagram When data collection efforts uncover many related issues, developing an interrelationship diagram can help identify which issues, themes, response categories, or parts of a process have the most influence, so that the root cause(s) can be isolated. The steps in creating an interrelationship diagram are as follows: 1. Write each issue on a separate card. Issues may come from affinity process headings (themes), response categories highlighted by a Pareto Chart, brain-stormed ideas, etc. The diagram works best when there are 5 to 15 issues. 2. Place the cards in a circle. 3. Starting at any card, ask if the issue influences any of the others. If it does, draw an arrow from the original card to the issue that is influenced. 4. Repeat for all cards. If any two issues both influence one another, draw an arrow representing only the stronger of the two influences. 5. For each card, count the total number of outgoing and incoming arrows. 6. Rank issues by their number of outgoing arrows, and focus on those with the greatest rank. Many outgoing arrows indicate a root cause, sometimes called a “driver”. Improving those issues will “drive” the most improvement overall. Figure 15 represents a process with eight major elements that need to be improved. To identify those which may be causing problems in other
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