Project Failure Source 5 - Estimating Techniques

Note: This posting is a continuation to the topic posted on June 24th and relates to my project management workshop titled "10 Ways to Increase Your Project's Success". In this post I discuss one of the sources of project failure and how we may mitigate this risk to our projects.

Source 5 - Estimating Techniques
Estimating technique errors arise when the project time estimates are based on guesses rather than experience with the activities and techniques used in the project or by actual results from similar projects. Issues arise when these estimates are not based on some prior experience. Additionally, issues arise when individual task estimates include padding to make sure each task includes contingency time and the entire project schedule is then based on these padded task estimates.

Effect on Project
Poor estimating techniques result in a project schedule that is unrealistic. Either optimistic guessing is used and the project does not have sufficient time to execute or padded estimates are used and the project is given too much time to execute. While the latter does not sound like an issue it actually is. If projects include too much, the resource estimates and schedule may be too large for the project to be approved.

Actions Taken by the Project Manager
All project estimates should be based on some type of educated guess. The educated guess uses experience in previous projects extrapolated to the proposed project environment. While this results in a guess, the guess is based on some form of reality and will be much closer to the actual times than simply throwing out an estimate that sounds good. Another very important aspect of estimates is to delegate this activity. Estimates should be formulated by the individuals doing the work. First of all, these estimates are more likely to be based on experience and also, the individuals will be more likely own to these estimates and therefore will work in a manner that ensures the work is completed within the estimates they provided. If the project manager provides the task estimates, they may not be based on experience and the individuals completing the work will not feel as committed to meeting the schedule than if they provided the estimates themselves.

Next Source: Optimism