The Benefits and Challenges of Estimating Work Times

Estimating the work times provides several benefits for the project manager. It gives an idea of the level of effort required to complete a project. This information then enables the project manager to produce a realistic plan based upon that effort. Estimating also helps the project manager anticipate the budget for the project. Allocated funds are largely based on the effort, or labor, to produce the product or deliver the service. The estimate becomes the basis for developing a schedule. Hours are converted to flow time, which in turn is used, with the interrelationships among tasks, to calculate start and stop dates. Lastly, doing an estimate breeds commitment. If the people who will do the work also help make the estimates, they will feel more committed to their tasks and keep within the allotted time. While it offers many benefits, estimating is not easy, for two reasons. First, it takes time and effort to develop reliable estimates. Many people take the path of least resistance and generate either an extremely pessimistic or an overly optimistic estimate. Good estimating requires extensive calculation and research to avoid skewing the calculated values. Second, estimating requires dealing with ambiguity. By its very nature, estimating has both knowns and unknowns. The unknowns can generate fear or cause people to react out of ignorance. Either way, confidence in the resulting estimate is low.

Types of Estimating Techniques:

1. Scientific wildly assumed guess
2. Global efficiency factor Title -----------
3. Productivity adjustment percent
4. Program evaluation and review, or three-point estimating, technique