Estimation

1
Estimation
2
Why Estimate?
3
Variation

• Varying skill levels
• Unexpected events
• Interruptions
• Mistakes and misunderstandings
• (from Effective Project Management, 2nd Edition,
  by Robert K. Wysocki, Robert Beck Jr., and David
  B. Crane)

4
Other Approaches

• Similarity to other activities
• Historical data
• Expert advice
• Delphi technique
• Simulations
• (from Effective Project Management, 2nd Edition,
  by Robert K. Wysocki, Robert Beck Jr., and David
  B. Crane)

5
Three Point Estimate
6
3 Point Estimation Worksheet
7
Formulaes

• Average (Pessimistic (4Most Likely)
  Optimistic) / 6
• Variance
• Standard Deviation Square Root of the sum of
  the variances

8
Exercise

• Do a 1 point estimate for your project how big
  do you think it is?
• Do 3 point estimates for the tasks in your
  project network logic diagram
• Set up a spreadsheet and calculate the average
  and standard deviation for the project
• Compare your 1 point estimate and the calculated
  results.
• What lessons did you learn through doing these
  calculations?