Estimating Project Management Time

"How much time should I estimate for project management in a project?"
This is a very common question asked by service providers whenever they need to provide estimates for projects that require a dedicated project manager.

"What? You mean not all projects have project managers?"
Well, what I mean is that not all projects require a project manager, but all projects require some level of project management. Otherwise, how would you account for one-man projects?

Then again, that's not the topic I want to discuss. What I would want to bring to the table are some basic rules whenever project management time is estimated into a project. So, how do you do it?

A general rule of thumb being used in IT software industries is that 20% of the team's work effort is added to allot for project management time. This means that if it takes 100 man-hours to do the work, 20% is added to it for project management. Hence the total effort for the whole project is 120 man-hours.

While this is a very generally accepted manner of estimating PM time. I would caution against taking this estimate as such. There are other factors that need to be taken into consideration when estimating the PM effort. These include the following:

Duration - Effort is different from duration. Effort is the amount of work needed to do the job. Duration is how long the work is going to take. If an activity requires an effort of 80 man-hours (or 10 man-days), then it can be done for a duration of either 10 days for 1 resource or 5 days for 2 resources. See the difference? The effort for project management is higher for projects with longer duration. This is due to the length of time (duration) that the PM is exposed to the project.

Resoures - This seems pretty obvious. The more resources in the project team, the higher the level of effort needed to manage the project. This is particularly due to the channels of communication needed to coordinate work between resources. Its obviously much harder to manage more people all at the same time.

You may wonder that if we go by the previous definition of effort vs duration, then the PM estimates of a project with a shorter duration with more people would just be the same as a project with a long duration and fewer people. It's true that these cancel out with one another. However, based on personal experience, the Resource factor has a bigger impact than the duration factor.

Risk - One of the basic activities of a project manager is to manage risks in a project. Therefore, if there is a lot risks in a project, the the project manager has got a lot of work in his hands.
The amount of risks increases the amount of project management time needed in a project. This trumps the other two factors in terms of how it impacts PM estimates.
Hopefully, this information helps you make better estimates for PM time, and helps you defend any estimates that you are creating.

"Now what the heck will you be doing with all those hours?" that's going to be in my next post.