Problem Investigations: Average Work Effort

[Cernnunos]

I work for a large telecommunications company that uses the following work effort time estimates for problem management investigations (Not SLA time scales)

P1/P2 Problem with PIR - 30 business hours to complete investigation
P2/P3/P4 Problems - 8 business hours to complete investigation

I am finding it difficult to qualify the amount of work effort per investigation as there are far to many variables for each investigation where some can take 30 mins to identify RCA and recommend PCA whereas others can take months just to get to root cause.

Has anyone else attempted to calculate work effort per investigation and if so what formula have you used to get averages that can be realistically used to ensure you have the right amount of resources to successfully facilitate this service?

Thanks in advance.

[Diarmid]

you would need thousands of problems to come close to useful averages.

And if whatever result you got was in any way related to the priority of the problems it would be a miracle.

Since priority is not the same thing as cost (because it includes urgency) there is no good reason to expect less time to be allowed for lower priority problems.

As well as the variability you mention there is the point that not all problems are worth the same degree of solution. You don't want to spend lots refining your solution (or even delving further towards "root cause") for problems of low value however high their priority might be. You only want them solved to the point of diminishing return.
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