Resource Leveling vs Resource Smoothing for PMP Exam
In the Project Schedule Management knowledge area of the PMP® Exam syllabus, Resource Leveling and Resource Smoothing are two of the most important Resource Optimization Techniques for project schedule development to allow most effective allocation of resources to allow the project to be completed as fast as possible. However, given the two techniques look very similar on the surface, many Aspirants would misunderstand them and fail to employ the best technique according to the situation described in the PMP® Exam questions.
Resource Leveling and Resource Smoothing
During “Develop Project Schedule”, activities are usually first sequenced and assigned resources based on the dependencies between different activities (either mandatory/discretionary dependencies) without consideration of the loading of different activities. Thus, some resources may be over-loaded. In order to solve this issue, Resource Optimization Techniques are employed.
- Resource Leveling: Resource Leveling is a resource optimization technique in which the Project Manager adjusts the start dates and finish dates of different activities in order to balance the demand for resources vs available supply.
- Resource Leveling is always carried out first
- e.g. Under normal situation, it is generally considered the man hour for each team member is 45 hours per week, if more than 45 hours’ work is assigned to a member in a particular week (which is not practical nor recommended by PMI), the activities must be adjusted by resource leveling and trimmed down to 45 hours — i.e. it takes more days to complete the activities than originally planned
- Resource Smoothing: Resource Smoothing is a resource optimization technique in which the Project Manager adjusts the timing of different activities so that the requirement for resources does not exceed a certain pre-defined limit.
- The pre-defined limit may be statutory or a company policy, e.g. no more than 38 hours’ work in a week
- After Resource Leveling, Resource Smoothing is used to ensure the demand for a particular resource is more balanced over time — i.e. if the original plan requires the resources to work 45 hours during the first 3 weeks but only 20 hours for the next 2 weeks, resource smoothing will try to “smooth” the hours per week to around 35 for the 5 weeks of the project duration
- While carrying out resource smoothing, care has to be taken to balance between the desire pre-defined limit and the overall duration of the project/activities. In this regards, the desired pre-defined limits may not always be possible.
For an aspirant named David, as he is having a full-time job, the maximum number of hours that can be devoted to exam prep is 20 hours per week. However, he prefers to work 10 hours per week in order to spare some time for his family.
As David wants to apply for the exam as soon as possible, he hope to finish his online course and get the 35 Contact Hours Certificate within two week. However, since it is estimated to take around 50 hours to be able to complete the online course and finish the final exam. The original plan is NOT feasible as he can only afford 20 hours per week. David has to employ Resource Leveling to extend the schedule to 2.5 weeks.
However, David also use Resource Smoothing to decrease the workload to around 15 hours per week in order to leave some breathing space. The final duration of the getting 35 Contact Hours Certificate is estimated to be around 3.33 weeks.
The end goal for the Resource Optimization Techniques:
- If it is for meeting resource constraints (e.g. statutory requirements, resource availability), Resource Leveling is employed. Resource Leveling is a necessary as the original plan is not practical and feasible.
- If it is for better utilization of resources or achieving the desired level of efforts (e.g. 38 hours per week to allow for some buffers of resources), Resource Smoothing is employed. Resource Smoothing is preferred but not absolutely necessary.
Resource leveling is always applied first before applying resource smoothing.