Anyone who knows me is going to find it extremely strange that I of all people should post a math formula! When it comes to managing your projects though there doesn’t seem to be any way around it. Your client is always going to want to know how long the project is going to take. You’re going to want to know too since you don’t really want to work for peanuts. It’s difficult at times when the projects are complex and lots of factors involved. I was discussing this with a friend the other day and it made me remember a formula they taught us that I think it pretty useful. I thought I would share it with you just in case you haven’t heard of it and are having trouble figuring out how to estimate your time on a project.
It’s called the Program Evaluation and Review Technique (PERT). It’s a pretty simple formula that goes like this:
Expected time = ( Optimistic + 4 x Most likely + Pessimistic ) / 6
The time you would tell the client is the expected time after you factor in the optimistic time (time it would be done if everything goes smoothly) plus the mostly likely that you are sure it could be done (x4) plus the time if everything goes wrong. Then you would divide all that by six and it comes up with a pretty accurate number of a length of a typical project!