Question

8. What are Mandatory /Discretionary/ External dependencies? Please give one example of each one.

Answer 1

Mandatory Dependency

Mandatory Project Dependencies are are legally or contractually required. They are, sometimes, inherent in the nature of the work. They are also called Hard Logic.

Consider 2 activities A and B. If B has a Mandatory Dependency on A then it means action on B cannot be performed until Action on A has been completed. Let us look at following examples to understand:

• A – Requirements Documentation; B – Client Approval
• A – Lay Building Foundation; B – Construct Floor
• A – Build Car Prototype; B – Perform Crash Testing

Discretionary Dependency

Discretionary Project Dependencies are defined by the Project Team. There could be more than one way to define a sequence between 2 activities. The Project Team may prefer one sequence over the other. The team would choose their preferred sequence because of best practices or lessons learned from prior experiences. These are also called Preferred Logic, Preferential Logic or Soft Logic.

Consider 2 activities A and B. A and B can be independently performed or one can be performed after the other. The Project Team can chose to make B dependent on A. Let us look at following examples to understand:

• A – Develop System Module X; B – Develop System Module Y
• A – Furnish Room R; B – Furnish Room S
• A – Book Airline Ticket; B – Buy Insurance

External Dependency

External Project Dependencies are defined between non-project Activities and project activities. The non-project activities are done by people who are external to the Project Team e.g. representatives from Client’s organization, Vendors’ organization or any other external groups. The project activities, on the other hand, are done by the Project Team. The Project Team usually does not have control over non-project activities.

Consider 2 activities A and B. If B has an External Dependency on A then it would signify that B is a project activity while A is a non-project activity. Following examples will be helpful in understanding:

• A – Client Go-Ahead; B – Initiate Project
• A – Delivery of Equipment; B – Start Development
• A – Approval of Building Plans; B – Start Construction