Using PERT on a task with multiple resources

[fxs]

I have a task that has two resources working on it. R1 and R2. R1 can spend
anywhere between 2 to 4 days on the task, and R2 can spend anywhere between
3 to 8 days on the task.

I could say that the task has a optimistic duration of 5 days, pessimistic
duration of 12 days, and a most likely duration of 8 days. But, how do I get
the resource hours to break up accordingly?

 

[Rod Gill]

You'll never get one task completely accurate. It will always be too
optimistic or too pessimistic. Go for most likely. I estimate work or
duration if everything goes well then add on the percentage chance it will
take twice as long. So 10days if everything goes well, and say a 20% chance
of it taking 20d. I therefore schedule 10+10*20%=12d

If on average you under and over estimate equally then your overall schedule
is great.

 

[fxs]

Interesting concept. Let's say I did this...

You'll never get one task completely accurate. It will always be too
optimistic or too pessimistic. Go for most likely. I estimate work or
duration if everything goes well then add on the percentage chance it will
take twice as long. So 10days if everything goes well, and say a 20%
chance of it taking 20d. I therefore schedule 10+10*20%=12d

If on average you under and over estimate equally then your overall
schedule is great.

--

Rod Gill
Project MVP
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