Software management

1. Project Task Duration Estimation
Prodea Florin, an IV-CTI

2. Steps in estimating
• A statement of scope or scope document that defines what
the project is and is not
• A task list in the form of a work breakdown structure (WBS)
• The task details defined (not simply a list of task names)
• Duration estimations provided by the team
• Task dependencies (schedule and risks) clarified
• Schedule risks identified, such as:Critical Path? (longest
consecutive, slack-less path)
• Planned schedule risk mitigation

3. Duration estimation ala PERT
• Program Evaluation and Review Technique (PERT) originated
in the 1950s during the U.S.N. Nautilus nuclear submarine
project.
• terminology and concepts:
– Optimistic = O
– Most likely = ML
– Pessimistic = P
– Task variance
– Normal distribution
– Task duration as a continuum of possibilities (probability)
PERT equation = [(O + 4 x ML + P) / 6]

4. Expanding the interval
• Expanding the confidence interval
• Cone of uncertainty:
• Impact on target date estimate:

5. What about reviews?
• Reviews are a primary feedback mechanism.
• For reviews to really work:
– Consider frequent in-process reviews
– No more than 30 days apart
– Update client after each review
– Eliminate surprises (this way the project wont be more 30 days out of
whack!)

6. • References:
• http://www.projectmagazine.com/planning/50-time/397-project-task-duration-estimation