Comments on: BAs and PMs working together (part 2)

By: Elizabeth

Elizabeth — Tue, 01 Dec 2009 19:38:57 +0000

Good advice – thanks!

By: Glen B. Alleman

Glen B. Alleman — Tue, 01 Dec 2009 01:45:49 +0000

One approach that has served me well over the decades is to always ask “what are the units of measure” of any number? When someone says “this improves your project management abilities.” In what units of measure. Or “I can reduce your risk,” in what units of measure?

By: Elizabeth

Elizabeth — Mon, 30 Nov 2009 22:09:13 +0000

Thanks, Glen, for pointing that out. It’s the difference between correctness and accuracy – and people not involved in project management would likely say the two words mean the same thing. So I think you saying that if I estimate a task will take 15 days I can be correct in my estimate (but we’ll only know that after the work is complete). But I need to express that as 15 days +/- 0% (or 15% or 90%) for it to be accurate. Except if I express it as +/- 90% then it isn’t particularly accurate, but at least we will know what we are working with!

By: Glen B. Alleman

Glen B. Alleman — Mon, 30 Nov 2009 19:03:05 +0000

Aaron and Elizabeth,

The confidence in an estimate is measured by it’s probability of be inside the error bands. The measure of accuracy is the confidence interval surrounding the estimate. So the original statement is Correct. Accurate estimates are needed for credible plans and cost.

One single point estimate can be correct. Only when the variance on that estimate is provided can it be accurate. Then the reader can assess the degree of accuracy in the estimate.

By: BAs and PMs working together (part 3) | A Girl's Guide to Project Management

Mon, 30 Nov 2009 05:36:13 +0000

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