In a recent Blog post titled Precision it is suggested Precision (or the implication thereof) is perhaps the root problem of most, if not all dysfunction related to estimation.
Yes, projects have uncertainty. Everything has uncertainty. Projects are no exception. Estimates have precision and accuracy, but the reason for these unfavorable outcomes is not stated in the post
But as the second paragraph of the post says The number of people walking around with the natural assumption that someone is to blame whenever an estimate turns out to be wrong is just sad. When you’re pushed to deliver a low estimate to secure a bid, and then yelled at for not being able to build the product in time afterwards — you just can’t win. This is another example of Bad Management and Doing Stupid Things on Purpose.
Using the chart from the post, showing the number of projects that went over their estimated effort, let's look closer at a process to sort out the conjectures made in the post about estimating.
Why is this the case? has no answer.
And by the way, this is not the same naive and simple-minded 5 whys used by #Noestimates advocates. The actual approach to asking Why is shown later in this post. This is like observing a number of people who are overweight and then claiming “being overweight” is the problem for these people. You need to find the Root Cause.
At times I work for the Institute for Defense Analyses, who produces Root Cause Analyses for software-intensive system of systems, here's an example Expeditionary Combat Support System: Root Cause Analysis.
When you find the Root Cause for those projects reported to be “overweight” you may also find the corrective action to the inaccuracies and imprecision of the estimates. OR it may be there were technical issues on the program that caused the overages.
Research has shown there are 4 “major” causes of cost and schedule growth in our domain Estimating is only One of those causes.
Without determining which root cause is the source of the unfavorable performance of the projects shown in the first chart, no suggestion for corrections can be made.
Start with Root Cause Analysis and only then suggest the reason for the problem. Here’s the process used in our domain http://www.apollorootcause.com/about/apollo-root-cause-analysis-method Buy the Reality Charting tool, buy Apollo Root Cause Analysis: Effective Solutions to Everyday Problems Every Time download Seven Steps to Effective Problem-Solving And Strategies for Personal Success Then this approach may be useful in your domain as well.
Then when you hear estimates are the smell of dysfunction you'll know that can not be correct without knowing the Root Cause of that dysfunction. And more importantly you'll know those making any suggestion for a fix to any problem when there is no Root Cause of that problem are just treating the symptoms and the problem will recur over and over - just like the recurring problems with project cost and schedule overruns.