A resource is a physical variable quantity such as manpower, material, money, equipment, time or space, which are required for carrying out a project.

Various activities of project are to be scheduled in such a manner that there is best possible utilization of available resources.

i) Resource Levelling

There are various activities in project demanding various levels of resources. The demand on certain specified resources should not go beyond the prescribed level. In the process of resource levelling, whenever the availability of resources becomes less than its maximum requirement, only alternative is to delay the activity having larger float.

In case, two or more activities require same amount of resources, the activity with minimum duration is chosen for resource allocation.

Steps involved in resource levelling:

1. Lower the peak requirement of resource by staggering the resource-input on non-critical activities. If necessary, sub-critical and critical activities can also be tackled to bring peak demands below specified level. Thus completion of work may be delayed due to resource constraint.
2. Either increase the duration of critical activities or place some of the concurrent activities in series to reduce peak demand of scarce resources. This will increase the duration of the project.
3. Re-arrange the activities in descending order of magnitude of positive float, as resources can be conveniently diverted from activities which possess large amount of float.
4. Firstly, lower the high peaks of resource demand by utilizing free floats of the activities. Then, Non-critical activities should be rescheduled to the extent required by utilizing the floats, starting with activities having the highest float. Critical activities can be tackled last, if necessary.

ii) Resource Smoothing

If the duration of completion of project is the constraint, then resources smoothing should be applied without changing total project duration. The period of minimum demand for resources are located and the activities are shifted according to float availability and requirement of resources. Thus intelligent utilization of float can smoothen the demand of resources to the maximum possible extent. This type of resources allocation is called as “Resource Smoothing.”

Steps involved in Resource Smoothing:

1. List out the resources which will be required for execution of the various activities and identify the ones which are considered important.
2. Resource profiles are prepared by carrying out the resource aggregation exercise and cumulative resource requirement for each unit are plotted in the form of histogram.
3. The periods of peak and low demands are identified and an attempt is made to lower the peaks and fill up the troughs.
4. If there is no constraint on the availability of resources, make the demand as uniform as possible. This can be achieved by altering the times of start and finish of non-critical activities, to start with. These activities can have certain amount of float. Therefore, available float can be used for making adjustments in the start in start and finish of the activities concerned and thus, lowering the peak demand by staggering of resource requirements without delaying the project duration.