Custom Fields in Microsoft Project

While working with our project manager to refine the schedule we kept finding tasks that had really long calendar durations (maybe due to not setting the correct priority or assigning and overloaded resource). As part of trying to track down these tasks, we found custom fields allow you to do Excel like VBA formulas.

This show two tasks, the first with a leveling delay (starting later than it could due to dependencies), and the second the type we were trying to find, where there is a 6 week task taking from August until November (3 months) to complete.

The first Leveling Delay is a built in field, but the Resource Duration Overrun was our new field. To create this read Create a custom field, and in the formula put:

<br />DateDiff("d",[Scheduled Start],[Scheduled Finish])-(ProjDurValue([Scheduled Duration])/480)<br />

This subtracts the ‘task duration in days’ from the ‘difference in start/end calendar dates in days’. It’s first fault is it counts weekend days for the calendar dates, but the durations is just working days. Taking this into account means you can’t reduce this field to zero for most tasks, but values like 54 in the above example shows something is wrong. The second fault is that is assumes you have 8 hour work days, thus the 480 is (hours per day * 60), as ProjDurValue returns the number of minutes of the task.

This graph is the Gantt view of those above tasks in the above example. The long calendar duration was due to having “Leveling can create splits in remaining work” turned on, in the leveler. And yes you can see the problem in the Gantt view, but panning left and right while scrolling through tasks is a pain, thus why been able to see large numbers allows you to find stand out tasks, and see if there is something that can or should be done about it.