Project Managers must be able to plan for and manage the dependencies among tasks in their projects. The more complex a project is the more dependencies there will be among project tasks that must be planned for. There are four different types of project planning dependencies in three categories.
Categories Of Project Planning Dependencies
Planning dependencies fall into three categories: logical, resource-based, or preference.
- Logical Planning Dependencies: These are dependencies that are logic driven. You can't paint a wall before it's built. You can't test a code module until after it's written.
- Resource-based Planning Dependencies: These are dependencies where the task coud be accomplished faster or sooner if you had more resources. The manual could be written faster if you had more than one writer. You could print more flyers except all the other printers are committed to other projects.
- Preference Planning Dependencies: These are tasks that could be scheduled differently, but the Project Manager chooses to schedule this particular order.
Types Of Project Planning Dependencies
There are four types of project plannng dependencies. They establish the relationships among the tasks. They are listed in the order most often used.
- Finish To Start (FS). The first task must complete before the second task can start. For example, the task "Write code module 1" must finish before the task "test code module 1" can begin.
- Finish To Finish (FF). The second task cannot finish before the first task finished. The task "all code tested" cannot finish before the task "test code module x" finishes.
- Start To Start (SS). The second task doesn't start until the first task starts. The task "write training manual" must start before the task "write chapter 1 of training manual" can start.
- Start To Finish (SF). The first task must start before the second task can finish. The task "assign coder for module 3" must start before the task "all work assigned" can finish.
Using Project Planning Dependencies
Dependencies establish the links, and the type of links, between all the tasks of a project. (There are also dependencies with other projects and that is covered in another article.) After you have prepared your Work Breakdown Structure (WBS), the listing of the project tasks
, you establish the dependencies between to begin to identify the critical path of your project.