Question

how can i make Activity duration estimates?

Answer 1

Acitivity duration estimates can be done through 5 ways

1.Analogous activity duration estimates

In this type we estimate the project based on the estimation of a similar past project. So we get an idea of the estimate. This gives entire duration estimate. We can get this information through operations management office or through manager. This saves time and cost. If we have less time to estimate the entire project we can use this sort of estimation. But this is not so accurate.

2. Parametric estimating

This is more accurate in nature. it is based on the calculations of historical data. If project is based on the same performed in the past this technique can be used.

3.Three point estimating

This is base don the assignment of resources, risk and uncertainity involved. This gives both best and worst scenarios and help in decision making. But this is cost effective. a lot of planning is required for it. This is done through PERT .ie. Program evaluation & Review Technique.

It includes three types of duration:

Most likely(M)

Optimistic(O)

Pessimistic(P)

M is based on resouces assigned to a particular project

O is based on the best scenario based analysis

P is based on worst scenario that can happen

The formula to derive the expected duration is

TE= (O+4M+P) / 6

TE is expected time

O is optimistic duration

P is pessimistic duration

M is most likely duration

4.Heuristic estimating

This is also termed as rule of thumb. This gives a roughly idea about this phase can take around 35% of the project. This is mainly based on experience. So experts generally talk about it.

5. Reserve analysis

This is a sort of contingency reserve in which we derive contingency reserve percentage to every schedule of the activity based on the past allocation of funds in the previous project.