There is no such thing as one root cause...
- The connected causes or causal chains as we call them continue forever in an infinite continuum moving out from the event. Lets say you were doing a root cause on your office mate tripping over your computer cord, and you took it to an extreme, if your office mate had not been born then the cord could not have been tripped over tripped by him today. Now we know you can not control your office mates parental breeding patterns in order to prevent the fall but the point here is that you can investigate and build well beyond your ability to effectively mitigate or eliminate the causes and you would still not be at the one root cause. The key here is to try to find the paths that lead to the systemic and latent causes and then take the time to evaluate solutions at that level for the best return on investment. This may mean that they may be out of your span of control but within the span of control of your managers or others allowing you to be successful.
- Rob Base and DJ E-Z Rock once said "It takes two to make a things go right" I would add "or wrong": With RCA those two things are existing conditions and instantaneous actions. There are always at least two causes per one effect therefor it should be called Root Causes Analysis. Using the example from above there was a cord which was the condition and a walking office mate which is the action. When you consider both you can look for the hidden causes and lowest cost solutions as you drill down into the problem.
- The cause of the event or reason for the RCA is the effect of it's cause.
- For example from above: Falling office mate was the effect of the action of walking across the floor. The action of walking across the floor was the effect of the action of you requesting help moving your monitor. In this example they are all effects rewritten they can all be causes. You requesting help with your monitor was the cause of your office mate walking across the floor and your office mate walking across the floor was caused of him tripping over the cord. The point is don't get hung up on either word. Use which ever you like the best to build the causal chains but to avoid confusion don't mix them together.
- You do not get a return on investment from a report. The return on investment comes from the implementation and verifications of the solutions. Why is this important? If I have to choose between spending all my time creating a beautiful report or spending my time ensuring implementation for the solutions then I choose the latter.