There are three basic types of interrelationships or dependencies:
• Mandatory dependencies (i.e., hard logic): These are dependencies that cannot change, such as erecting the walls of a house before putting up the roof.
• Discretionary dependencies (i.e., soft logic): These are dependencies that may be at the discretion of the project manager or may simply change from project to project. As an example, one does not need to complete the entire bill of materials prior to beginning procurement.
• External dependencies: These are dependencies that may be beyond the control of the project manager such as having contractors sit on your critical path.
Sometimes, it is impossible to draw network dependencies without including dummy activities. Dummy activities are artificial activities, represented by a dotted line, and do not consume resources or require time. They are added into the network simply to complete the logic.
In Figure 12-5, the dummy activity is required to show that D is preceded by A and B.
Was this article helpful?
What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.