How to Avoid the Most Common Mistake in Microsoft Project

Microsoft Project is widely used by project managers across the World, but many are unaware of the traps they are falling into when teaching themselves.

The most common of these is the habit of entering start and finish dates for tasks. It is easy to see why PMs fall into this trap as one look at the Task Sheet seems to suggest that this is what should be done. There is a column for both start and finish dates and the assumption is that as tasks must be scheduled, these must be manually entered. In fact, entering dates directly into these fields creates what MS Project refers to as a ‘constraint’. A constraint prevents a task from automatically rescheduling if it is affected by another task and whilst sometimes this is desirable, it takes away much of the software’s flexibility.

The correct way to determine start and finish dates is by creating ‘dependencies’ between tasks. Dependencies allow us to schedule tasks depending upon the relationships w between them within the project. For example, if we have a task which is to lay foundations for a building and the another which is to build the walls, the walls must be erected after the foundations have been completed. The relationship between these two tasks is what MS Project describes as ‘Finish to Start’. In other words, the second task cannot start until the first task has finished. Scheduling tasks in this way ensures that the plan remains flexible and is free to move should we encounter a deviation from our original project.

There are 4 dependency types:

  • Finish to Start
  • Start to Start
  • Finish to Finish
  • Start to Finish

Using these linkages in combination within the project we can schedule tasks to begin and end precisely on time and leave us with the option to reschedule should the need arise. To create task dependencies, double click on a task name to open the information window. Select the Predecessors tab and then type the ID of the task you wish to link back to (note that we always link backwards to an earlier task). The dependency type can now be chosen by clicking in the Type field and selecting from the menu.

Microsoft Project is a remarkably flexible scheduling tool if it is used correctly. By making sure that you link your tasks through the correct choice of dependency, you will ensure that you get the most from what the software has to offer.