There are several ways to mitigate resource over-allocation in Primavera P6. Let’s look at alleviating resource over-allocation by reducing daily effort of the resource in question.
You may have a schedule with accurate activity duration estimates and sound logic. However, if your resources are over-allocated your schedule is not realistic. Yes, when resources are stretched thin your project schedule most likely will not proceed according to plan.
But what can be done to confirm that the schedule executes successfully in the real world of limited resources? Well, there are several ways to handle resource over-allocation in Primavera P6. We summarize the most noteworthy ways to mitigate resource over-allocation in the article Ways to Handle Resource Over-Allocation in Primavera P6 Professional.
You will find that each mitigation technique comes with its own advantages and disadvantages. The negative of many mitigation approaches is that they tend to extend the length of the project. Today we want to demonstrate how to mitigate resource over-allocation in a way that will not delay the project.
This article demonstrates mitigating a resource over-allocation by reducing daily effort of a resource on an activity.
When your resource is over-allocated first consider the assigned daily effort of the resource. Is the resource’s allotted daily effort necessary to complete the activities in question? If not then you, as the project manager, may want to negotiate the resource’s required daily effort with the line manager and individual doing the work (note that the project manager assigns trade skills to a schedule and the line manager assigns the actual individuals doing the work to these trade skills).
In this way you reduce padding, where additional time and/or effort are allotted to an activity for no good reason other than to ensure on time or earlier-than-scheduled completion.
You may find in many situations that the required effort of the resource is legitimate. In these scenarios look for opportunities to lengthen an activity and proportionately reduce the daily effort of the assigned resource. Here the overall work or units stays the same, but the daily effort of the resource becomes less.
In many cases lengthening an activity extends the project length. However, if an activity is not critical and therefore has total float you could extend the activity for the duration of its total float. So, if your activity has total float this is a good opportunity to look to lengthen the activity duration and respectively reduce the resource’s daily effort. In doing this you achieve a more realistically allocated resource without postponing the project end date.
Let’s demonstrate lengthening activity duration to reduce daily effort (or units/time in Primavera P6). We have in Figure 1 our demonstration project.
This is an electrical substation construction project. Note that the cable splicer is over-allocated several days in February. This is because we are asking the cable splicer to work 10-hours/day on three different activities simultaneously. Performing these activities in series eliminates the resource over-allocation but extends the duration of the project.
Examining the schedule further we observe that the install grounding activity has 15-days of total float. We could therefore extend the length of install grounding 15-days and decrease the daily effort of the cable splicer on this activity a proportionate amount.
We currently are asking the cable splicer to work 20-hours in 2-days or 10-hours/day. We could extend the duration of install grounding so that the cable splicer works 20-hours in 15-days or 1.3333-hours/day. Well it seems more reasonable to have the cable splicer work at least 2-hours/day on this activity so we decided to extend install grounding to 10-days.
Proceeding we display the current cable splicer resource assignment on the install grounding activity, Figure 2.
Before we extend install grounding, we need to update the duration type for this activity. Currently, the duration type is fixed duration and units/time. We need to change this to either fixed units or fixed duration and units. Let’s proceed and change the duration type to fixed duration and units, Figure 3.
Now we update the cable splicer’s original duration on the install grounding activity, Figure 4.
Observe that the cable splicer’s budgeted units/time decreases to 2-hours/day. All the other install grounding resource assignments are not affected by this update.
Continuing we set the original duration of the ground wire to 10-days to distribute the material usage over the cable splicer’s 10-day effort. This decreases the ground wire usage to 56-LF/day, Figure 5.
We recalculate the schedule and in Figure 6 we again display the resource usage profile of the cable splicer.
The cable splicer is still over-allocated, but we see a decrease in the cable splicer’s peak over-allocation on Friday and Monday. We continue our mitigation efforts by extending the original duration of the cable splicer’s assignment on install bus and jumpers from 8-days to 16-days.
Before proceeding we again must update the duration type of this activity to fixed duration & units. The resulting budgeted units/time of the cable splicer for install bus and jumpers becomes 5-hours/day, Figure 7.
Our final mitigation effort could be negotiating the required effort of the cable splicer on the lay control cable activity. This is a critical activity, so extending its duration would lengthen the project and, therefore, is not a good option. We choose to negotiate and reach agreement with the line manager that the cable splicer can work 3-hours/day on lay control cable.
This time when we make the update, we can leave the duration type to fixed duration and units/time. We have negotiated and now specified a new decreased daily effort, and the line manager has agreed to the resulting lower budgeted units and budgeted cost for the cable splicer working on this activity, Figure 8.
After making these updates to our schedule the resource usage profile of the cable splicer plots in Figure 9.
Now our cable splicer is no longer over-allocated. So, by extending activity duration to decrease daily effort and negotiating to decrease effort we have completely mitigated the cable splicer’s resource over-allocation.
Again, there are several ways to mitigate resource over-allocations on a project. If the schedule is duration constrained, consider adjusting the respective resource’s daily effort.
If your activity has float, you could extend the activity duration, as per the float, while reducing daily effort proportionately. Remember when you do this to set the duration type to fixed duration & units or fixed units.
You could also negotiate the required effort of the activity and adjust the effort and budgeted cost respectively. When you make this update keep the duration type at fixed duration and units/time. So, reducing daily effort to mitigate resource over-allocation is a promising way to distribute and/or adjust effort without extending the length of the project.