Final answer:
Resource smoothing is applied when two or more activities require the same resource. It helps to avoid over-allocation without impacting the project's schedule. The correct option is 'c' in the multiple-choice question.
Step-by-step explanation:
The priority rules for resource smoothing are applied when two or more activities require the same resource. Resource smoothing, also known as resource leveling, is a technique used in project management to address the allocation of resources when there are fluctuations in resource demand over the course of a project. This process is particularly important when resources are limited and cannot be over-allocated without causing delays or conflicts within the project.
Resource smoothing is utilized to ensure that resources are allocated as evenly as possible, avoiding peaks and troughs in resource usage, while still maintaining the project's schedule. The technique involves adjusting the start and finish dates of non-critical activities to smooth the demand for resources. These adjustments are made within the float or slack time which is the amount of time that a task can be delayed without affecting the subsequent tasks or the project's overall completion date.
When applying resource smoothing, there are several priority rules that may be used to determine which activities should be smoothed first. These priority rules might include ordering activities by their earliest start date, the amount of available slack, the duration of the activities, and the importance or strategic value of the activities to the project. Resource smoothing will not affect the critical path of a project; rather, it seeks to optimize resource use on activities that have flexibility in their scheduling.
Therefore, the correct option is c. when two or more activities require the same resource.