Task dependencies are the relationships between tasks that determine the order in which they must be completed. They are used to ensure that all tasks are completed in the correct sequence and that no task is started until its predecessor has been finished. Task dependencies can be either internal or external, depending on whether the relationship is between two tasks within a project or between a task and an outside factor.
The four main types of task dependencies are finish-to-start (FS), start-to-start (SS), finish-to-finish (FF) and start-to-finish (SF). In a finish-to-start dependency, one task must be completed before another can begin. For example, if you need to paint a wall before you can hang wallpaper, then there is a finish-to-start dependency between painting and hanging wallpaper. Start-to-start dependencies involve two tasks that must begin at the same time. Finish-to-finish dependencies require both tasks to be completed before either can be considered finished. Finally, start-to-finish dependencies require one task to begin before another can end.
Task dependencies help project managers plan their projects more effectively by ensuring that tasks are completed in the right order. This helps to reduce delays and ensures that resources are used efficiently. Additionally, task dependencies help project managers identify potential risks and develop strategies for mitigating them. By understanding how tasks depend on each other, project managers can better anticipate problems and take steps to prevent them from occurring.