Constraints, Assumptions, and Project Activities

The PMBOK Guide describes a constraint as "anything that can limit the project management team's options." If a constraint is going to limit you, wouldn't it be better to completely avoid it?

Of course it would. Unfortunately, you cannot always avoid constraints, which can create risk. Therefore, project managers should learn to handle constraints—which are inputs to activity duration estimating—so their effects on a project are minimal.

There are two major types of constraints that a project manager must consider when determining the duration of an activity—imposed dates, which are required, and major milestones, which are requested.

• An imposed date is a date that cannot be changed and must be met by the project team.

• A major milestone is a project activity that upon completion will be delivered to the client.

Another input to project activity duration estimating is assumptions. Assumptions are factors that are considered to be true, real, or certain. Over the course of the project, these factors may turn out to be true or false.
Project managers should be extremely careful when making assumptions about a project. Assumptions carry a degree of risk and should be used only when the degree of certainty about the assumption is high.

Remember, constraints and assumptions can cause a risk to your project. With proper planning, you can minimize or avoid the impact of the risk.