Understanding Task Relationships In Microsoft Project

Interested in learning how to create links between tasks in Microsoft Project? Want to know what F-S, S-S, F-F and S-F mean? Then read this article to find out and increase your knowledge of Project at the same time.

Have you felt confused applying different types of relationships between tasks? Do you want to know the difference between Finish to Start and Start to Start? This article takes a look at the different kinds of task links and describes how each are used.

After you've created project tasks and set durations, the next step in building your project plan is to link tasks together. Because each task has a start and a finish, you can link two tasks together in four different ways. These are Finish to Start, Start to Start, Finish to Finish and Start to Finish.

The first task link type is the Finish to Start, shown as F-S. This is the most commonly used type in Project and means that one task is finished before the next can start. So F-S tasks are completed in a series. If you delay the finish of the first task, this will delay the start of the second.

To see this in action, start a new project file and create two tasks, with your own choice of names and task durations of 1 day each. Now highlight both, and then click on the "Link Tasks" button in the upper toolbar. Project creates a Finish to Start link which you can see on the Gantt chart. The tasks are linked by a blue line pointing from the finish of the first task to the start of the second. Project defaults to applying this type of task link if you use the Link Tasks button.

The second task link type is the Start to Start, shown as S-S. This link is often used to start two activities in parallel to save time. Although both are carried out at the same time the start of the second task is triggered by the start of the first task. So the first task start drives the second task start. So if the start of the first task is delayed, the start of the second task is also delayed.

To create this second type we'll first create the link in the same way as above. Highlight both tasks and click the Link Tasks button. This will create a Finish to Start link which you can see in the Gantt chart. We're going to change the type of link. To do this, carefully hover your mouse over the actual blue link linking the tasks on the Gantt chart and double click. You may need to expand the Gantt chart timescale so you can see the blue line clearly.

The Task Dependency panel should open. Click on the pop down to the right of Type and choose Start to Start and click OK to finish. You'll see the distinctive parallel link between the tasks lined up on the task starts. The arrow points from the first task to the second task showing which one is the driver.

The third task link type is the Finish to Finish, shown as F-F. This link is used to plan task completions at the same time. This type is often used to plan completion of jobs at the same time such as for a product launch or a building completion. Don't forget the first task finish determines the second task finish. Delay the first task finish and the second task finish is also delayed.

To create this third type we'll create a F-S as described earlier and then edit the link type by double clicking the line in the Gantt chart and this time choosing Finish to Finish. Once completed you'll see the parallel link lined up on the task finishes. The task the blue line points from determines the finish of the other task.

The fourth task link type is the Start to Finish, shown as S-F. This link type is used more rarely in project planning. If you link two task with a S-F link the planned start of the first task determines the planned finish of the second task - a bit like a just in time system. So if the first task start is delayed, the planned finishing of the second task is also delayed.

To create this fourth type we'll create a F-S as described earlier and then edit the link type by double clicking the line in the Gantt chart and this time choosing Start to Finish. Once completed you'll see the S-F link showing the finish of the first task linked to the start of the second. Because the link is S-F the second task will show ahead in time of the first task, even though it occurs after the first task in the plan.

So hopefully this article has given you a glimpse of the world of project task relationships. You'll now see how serial and parallel project paths are developed and know how these links work will help you understand how project plans change if task start or finish dates are altered.

Attending a Microsoft Project training course would be a really good way to really boost your understanding of Project and help you develop your skills.