BY ORDER OF THE AIR FORCE PAMPHLET 91-215 SECRETARY ...

A2.A.9. THE CAUSE AND EFFECT TOOL
A2.A.9.1. FORMAL NAME. The cause and effect tool
A2.A.9.2. ALTERNATIVE NAMES. The cause and effect diagram, The fishbone tool, the Ishikawa
Diagram
A2.A.9.3. PURPOSE. The cause and effect tool is a variation of the logic tree tool and is used in the
same hazard ID role as the general logic diagram (i.e. a more rigorous, detailed tool). The special
advantage of the cause and effect tool is its origin in the quality management process and the thousands of
personnel who have been trained in the tool. Because it is widely used, thousands of personnel are familiar
with it and therefore require little or no training to apply it to the problem of detecting risk.
A2.A.9.4. APPLICATION. The cause and effect tool will be effective in organizations that have had
some success with the quality initiative. As pointed out above, the tool is among the most commonly
applied quality procedures and significant numbers of personnel are very comfortable using it. It should be
used in the same manner as the logic diagram previously covered and can be applied in both a positive and
negative variation.
A2.A.9.5. METHOD. The cause and effect diagram is essentially a logic diagram but with a significant
variation. The cause and effect diagram is provides more structure than the ordinary logic diagram through
the branches that give it one of its alternate names, the fishbone diagram. Figure A2.19 illustrates this
structure. Note that there are two basic variations, one for tactical type operations (the 4 “M”) and
another for administrative processes (the 4 “P”). Of course the user can tailor the basic “bones” based on
special characteristics of the operation or mission that is being analyzed. As in the case of the logic
diagram, either a positive or negative outcome block is designated at the right side of the diagram. Then,
using the structure of the diagram, the user or team of users completes the diagram by adding causal
factors in either the “M” or “P” structure. By using branches off the basic entries, additional hazards can
be added to the diagram. The examples provided illustrate this process. The cause and effect diagram is a
very effective team hazard ID tool and should be used in a team setting whenever possible.
A2.A.9.6. RESOURCES. There are many publications describing in great detail how to use cause and
effect diagrams.
A2.A.9.7. COMMENTS. This procedure has proven very effective and has established the cause and
effect diagram as a powerful hazard ID tool.
A2.A.9.8. EXAMPLES. An example of cause and effect tool in action is illustrated at Figure A2.19.
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