Estimation Matters

Over the years I've seen very little attention given to estimation of software projects. The work put into estimation isn't particularly glamorous and the work is difficult.  Iakes years of experience to learn, and is never perfect. Yet with so little attention given to estimation, consider that one of the most common, and earliest questions asked when considering a software project are "what hard will it be?", "when can it be finished?" The answers to which, though typically given by an expert, are often given with little detailed analysis. 

The consequences of poor estimation can be severe, though they aren't always obvious. Consider the following effects of poor estimation.

1. Schedule overrun - Without attention to estimation, the project is subject to schedule overrun. Failing to deliver the project on - or close to - plan results in resources not becoming available for subsequent projects (a domino effect of delays), cost overruns, and a lost of confidence from project sponsors.
2. Resource burnout - Without proper estimation of effort, to hit deadlines you will find that your resources will need to work long hours - evenings and weekends - to hit deadlines. Having to do so on a regular basis leads to resource burnout and ultimately turnover.
3. Quality problems - To hit unrealistic deadlines corners are often cut. These cuts often occur in testing, but you'll find that quality suffers due to rushed execution and tired resources.
4. Wasted hours -  When overestimation occurs (rare, but it does happen!) you will find that resources will still leverage the entire duration of the planned schedule. Where the project could have been completed early, freeing resources for other projects, they will be used inefficiently, filling the time allotted. Overestimation will often masquerade as accurate scheduling when in reality you experiencing missed opportunities.

Accurate estimation is well worth the time, but you need to be willing to expend the effort to do it correctly. It is worth the effort to have your teams learn to do it right.