Resource leveling vs Resource Smoothing

Resource leveling vs Resource Smoothing

One of the downsides of Critical Path method is the imbalance between resource availability and allocation. This ends up having resources over allocated than what the availability permits. Resource optimization techniques are used to level the resources. The two techniques used to level the resources are Resource leveling and Resource Smoothing

Resource Leveling:

In the first diagram above, resources are over allocated for week1 and week 2 for more than 40 hours. However in the second diagram, you can see that all the resources are allocated within the 40 hour window; meaning the resources are levelled within their availability. The caveat of this technique is that the schedule could get extended. In the first diagram, the project would have taken 5 weeks to complete whereas in the second the schedule got extended to 6 weeks.

Resource Smoothing:

You use Resource Smoothing when you have to optimize the resources and you cannot extend the schedule. Since you cannot extend the schedule, the project completion date and the critical path will stay the same.

In the first diagram above, resources are allocated for 40 hours on week 1 and 2, whereas other weeks they are allocated less. In the second diagram, the resources are allocated within 35 hour weeks considering the float on weeks 3, 4, 5, and 6. This helps to smoothen the resource usage to 35 hours per week utilizing the float available in the schedule.

Time is the main constraint here. You have a fixed schedule and are asked to optimize resources.