Dependencies between tasks can be set within a project or across multiple projects. Task dependencies are logical relationships that show how tasks are linked to each other and how they relate to their parent projects and sub-projects.
In order to define and establish dependencies between project tasks, there should be a criterion that determines the nature and type of dependency. For example, time can be used to define relationships between start and finish of tasks. Risks help determine dependencies between tasks affected by same threats and uncertainties. Resources establish links between activities that belong to a critical path.
Regardless of what criterion to use in setting task dependency, there is a sequence of generic steps that help break down a project into a series of dependent activities. These steps are:
- Create a general list of tasks and activities that are necessary to perform project work
- Develop a work breakdown structure (WBS) in which broader activities are divided into smaller tasks
- Finalize the WBS by adding hierarchical levels that organize all tasks into work groups
- Use time estimates to determine task durations
- Evaluate risks that impact project tasks
- Estimate resources required for tasks
- Decide what dependency criterion to use in setting links between tasks
- Establish task dependencies by using the criterion.