Mandatory Dependencies
Mandatory dependencies are those that are legally or contractually required or inherent in the nature of the work, often involving physical limitations.
Explanation
Mandatory dependencies, also called hard logic or hard dependencies, represent relationships that cannot be changed by the project team. They arise from the physical or contractual nature of the work being performed. For example, in construction, a foundation must be laid before walls can be erected. This is a physical constraint that cannot be altered regardless of project preferences.
Mandatory dependencies are identified during the Sequence Activities process and are distinguished from discretionary dependencies, which the team can choose to modify. Recognizing whether a dependency is mandatory or discretionary is critical for schedule optimization. When the team needs to compress the schedule through fast tracking, only discretionary dependencies can be relaxed. Mandatory dependencies must be respected.
Mandatory dependencies can be internal (within the project) or external (involving outside entities). For example, a contractual requirement to deliver a component by a certain date before the next phase can begin is a mandatory external dependency. Understanding the nature of each dependency helps the project team make informed decisions about schedule changes and risk.
Key Points
- •Also called hard logic or hard dependencies
- •Cannot be changed by the project team
- •Arise from physical limitations, legal requirements, or contractual obligations
- •Must be respected during schedule compression efforts
Exam Tip
When fast tracking, only discretionary dependencies can be adjusted. Mandatory dependencies are fixed and cannot be changed regardless of schedule pressure.
Frequently Asked Questions
Related Topics
Discretionary Dependencies
Discretionary dependencies are established by the project team based on knowledge of best practices, preferred sequencing, or past experience, even though other sequences are possible.
External Dependencies
External dependencies involve a relationship between project activities and non-project activities that are outside the project team's control.
Internal Dependencies
Internal dependencies involve a relationship between project activities that are within the project team's control.
Fast Tracking
Fast tracking is a schedule compression technique in which activities or phases normally done in sequence are performed in parallel for at least a portion of their duration.
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