Dependencies are logical relationships between project activities. The dependencies of tasks mean that you cannot proceed to another task if the first task is not finished yet. In project management, it is important for the team to deliver projects in a sequential manner. Understanding dependencies are crucial to creating a strong project schedule.
There are different types of dependencies and these include mandatory, discretionary and external dependencies. The external dependency is defined as the relationship between project activities and non-project activities. Such dependency involves things that are beyond the control of the project team but should be reflected in the project schedule.
Examples of external dependency include getting approval from an external organization before starting the project activity. Completion of the project milestone after the completion of a previous milestone is also a good example of this type of dependency. A good analogy for this is if you are constructing a residential building, you need the local municipal corporation to build a road. The road is external to your project. Without it, you cannot even proceed to construct your residential building or even hand the units over to the tenants.
It is important for project managers to manage external dependencies. In project management, there are techniques used to manage these dependencies so that the project schedule can still push through. Establishing a dependency log or register is very important so that project managers will know which factors to look out for when planning their schedule in the future. Monitoring is also important in managing the external dependencies. Having regular meetings to review the dependencies is very important. Lastly, when the dependency has been met, project managers need to mark it in the log for future references. This will be an important information that will guide the project manager for future activities.
This term is defined in the 5th edition of the PMBOK.