Define Activity Constraints
Explanation
Use this activity to define constraints for existing activities, which introduce conditions or limitations that
affect the timing and execution of those activities. Constraints are used to address real-world restrictions such
as deadlines, resource availability, or delayed input, ensuring the project schedule remains realistic and
achievable. Constraints play an important role in scheduling calculations by refining the schedule to accommodate
project-specific requirements. They help align activity timing with milestones, contractual obligations, and
resource constraints.
Constraints can be used to:
- Set fixed start or finish dates for specific activities.
- Limit the earliest or latest possible start or finish times.
- Ensure compliance with project milestones or external deadlines.
In Activity Scope and Schedule, use the Add/Modify Constraint
command to define the applicable constraints.
Possible Constraints
Constraints can be defined using the following types:
- Start Not Earlier Than: The activity cannot start before the specified date.
- End Not Later: Than The activity must finish by the specified date.
- Must Start On: The activity must start on the specified date.
- Must End On: The activity must finish on the specified date.
- As Late As Possible: The activity should be scheduled as late as possible without delaying
the project’s finish date.
Prerequisites
- Activities must already exist in the project.
System Effects
As a result of this activity:
- Logical dependencies are established between activities, forming an activity network.
- The system uses this network in project scheduling to:
- Calculate the critical path, identifying which activities directly affect the project’s end
date.
- Determine float/slack, helping identify which activities have scheduling flexibility.
- Ensure dependent activities are updated during rescheduling, so when one activity is changed, all linked
activities are adjusted accordingly.
- Support impact analysis, making it easier to assess how delays or changes affect the overall project
timeline.