When you prepare your project plan, you may be faced with factors that have a negative impact on the project and your planning activities. Two such factors are project constraints and assumptions.
Project constraints and assumptions can be a source of frustration for the project team, especially when the constraints are too stringent and the assumptions invalid. To reduce frustration and enhance efficiency you need to carefully manage constraints and assumptions as you prepare the project schedule.
Constraints, as inputs to schedule development, are factors that limit the project management team's options. There are two main types of constraints that project managers must consider when developing the project schedule: imposed dates and major milestones. Imposed dates - Completing certain deliverables by a specific date may be required by project sponsors, customers, or other stakeholders. Major milestones - You may also be asked to complete a certain phase or aspect of the project by a certain date. These dates will act as constraints, requiring you to make decisions to see that imposed dates and milestones are reached on time.
PMBOK defines assumptions as, "factors that, for planning purposes, will be considered to be true, real, or certain."
Project managers must often make assumptions in planning the various stages of a project. Assumptions generally involve a degree of risk, therefore they must be carefully monitored during a project's life cycle.
Consider this example. Tell-4-Funds, a telemarketing company, has recently been contracted by a client to lead a national fundraising campaign. The client would like to have the campaign finished in three weeks, in order to begin the next phase of its long-term plan. Tell-4-Funds has just begun the project's schedule development. It has made the assumption that the telemarketers can create the calling lists in two days and begin...