Have you created or used a project plan in Microsoft Project? Then you'll know that the key way tasks interact is through task relationships. Find out in this article about the four different kinds of task relationships and how to create them.

When you create a new project plan Project assumes that all tasks will be done as soon as possible. So if you create two tasks, each with a name and different durations, both tasks will appear on the Gantt chart as starting on the project start date. However we can link these two tasks together in different ways to make one task dependent on the other. We can create links or relationships between tasks in four different ways. These are Finish to Start, Start to Start, Finish to Finish and Start to Finish. We'll now look at each of these relationships in turn.

Finish to Start

When we describe a task relationship, the first word is applied to the first task and the second word to the second task. So a Finish to Start relationship means that the finish of the first task controls the Start of the second task. This is often shown as FS. Another way of describing this is to say the first task precedes the second task. So if we look at the details of the second task we'll see that it shows the first task as preceding it. This task relationship means that if the duration or finish date of the first task is changed in any way, for example caused by a planned task delay, then the start of the second task will change to match this.

To create a Finish to Start relationship in Project we select the first task and then the second task in the left hand task table. We then click the link icon on the upper toolbar or ribbon tab to create the relationship. This will show as a blue line on the right hand Gantt chart, with the tail of the blue line starting at the end of the first tasks and the arrow finishing at the start of the second task. This task relationship is the commonest type in a project plan and means that the tasks are completed in sequence, so that when one completes the next one starts.

Start to Start

A Start to Start relationship means that the Start of one task controls the Start of a second task. So once the first task has started, both tasks progress in parallel. If the start of the first task is delayed, then so is the start of the second task. To create a Start to Start, or SS relationship, first create a regular Finish to Start relationship by highlighting both tasks and then clicking the link icon. Then you need to change the relationship type. To do this, carefully hover your mouse over the blue relationship line between the tasks on the Gantt chart, and double click the mouse. The Task Dependency panel appears. Click the pop down selector next to Type and choose Start to Start. Then click OK to finish. Now the task relationship will show as Start to Start on the Gantt chart, with the blue line pointing from the start of the first task to the start of the second.

Finish to Finish

A Finish to Finish relationship means that the finish of the first task controls the finish of the second task. So in the project plan, if the finish of the first task is changed, for example because it will take longer than expected for parts to be delivered, then the finish of the second task is also delayed. You create a Finish to Finish, or FF relationship by again first creating a regular Finish to Start relationship, and edit the relationship type on the Gantt chart. This time you choose Finish to Finish in the task dependency panel and click OK to finish. Now you'll see the Finish to Finish relationship showing as a blue line pointing from the end of the first task to the end of the second.

Start to Finish

A Start to Finish relationship means that the start of the first task controls the finish of the second task. In our project plan we want the start of the first task to control when the second task finishes. So if for example the first task finish is delayed, for example if staff arrival onsite will be delayed, then this would delay in the plan when the second task finishes, for example a materials delivery. You build the task relationship similar to before. So first create a Finish to Start task, then on the Gantt chart edit the task relationship and change the type to Start to Finish.

So we've covered how the four basic types of task relationships can be created. In each case there is always one task which controls the start or finish of another task. Interested in finding out more about working with tasks in Project? A really effective way is to attend a training course. That way you can gain lots of new skills in a short time.