AAOM Handbook

INTERNAL

AI.12 Rank Potential Causes Context

Brainstorming should result in the identification of many potential causes for an issue. Because the brainstorming process is deliberately free flowing and non judgemental, the list of potential causes generated may include many that have a common theme, or that are similar if not essentially the same. Identification of these common themes and similarities can make the further investigation easier and quicker. There are a number of techniques, such as fishbone diagrams, affinity tables etc, that can be used to identify and record these themes or similarities. Before we can conclude which is the significant contributing/root cause(s) of the issue we must collect and evaluate the data necessary to validate whether any of the potential causes is significant. For an issue with a large number of potential causes this may be a lot of work. In order to make this workload manageable we interpose a step to rank the potential causes from the most to least likely. We then validate from the most probable cause and proceed until we have confidently identified the significant contributing/root cause(s). Purpose To rationally organise and rank the potential causes for an issue from most to least likely. Quantity One list of potential causes in descending order of ranking. Quality For smaller numbers of potential causes and categories fishbone diagrams can be effective for grouping. For a large number an affinity table may be more effective. Suggested causes that are identified to be the same during this process may be grouped into a single definition that captures the essence of the separate suggestions. In ranking the potential causes consider;  The probability that it is contributing to the issue.  The extent that it is contributing to the issue. Consider using an exponential weighting system to clearly differentiate potential causes – as per the following table;

© McAlear Management Consultants 2007

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