Resource constraints are a common issue that impact project managers (PM). To manage resource allocation constraints, a PM can utilize either heuristics or optimization models (Meredith, Shafer and Mantel 2017, 366-367). Heuristic approaches, or rule of thumb approaches, are the most common and there are variety of priority rules that can be used in this approach to allocate resources in constrained projects. The default priority rule for scheduling is typically the “as soon as possible” rule where resources are focused on the critical path. Another rule is the “as late as possible” rule where all activities are scheduled as late as possible without causing delays. This rule is particularly useful for an organization that is looking to defer cash outflows for as long as possible (Meredith, Shafer and Mantel 2017, 369). Another commonly used rule is the “shortest task first” rule. An organization looking to accomplish the maximum number of tasks within a specific period of time can implement this rule (Meredith, Shafer and Mantel 2017, 370). While these rules are useful, and there are many more rules, one of the most useful rules tends to be the “minimum slack first” rule (Meredith, Shafer and Mantel 2017, 370). With this rule, whatever tasks have the least slack should be completed first. This ensures the critical path is well managed in addition to providing a way to prioritize subsequent activities based on their importance to the timeline.
Choosing a priority rule to use can potentially be confusing for a PM. As mentioned previously, a rule that can be used that is one of the most successful is the “minimum slack first” rule. However, if an organization is concerned that some of the most important large tasks within a project may not be completed due to scarce resources, the “most resources first” rule could be utilized instead (Meredith, Shafer and Mantel 2017, 370). This ensures that the resources will be available for important tasks. For example, it would benefit a construction project to focus on pouring the concrete foundation for a new building first as opposed to focusing the limited amount of concrete on pouring the sidewalks or ornamental elements first and then running out of material for the important building foundation. The sidewalks and ornamental elements may be able to be finished with other materials, or scrapped entirely if necessary, but the building foundation is important to the entire project’s overall results. Different organizational and project needs may lead to the use of different priority rules. It is important for a PM to understand the needs of the organization, and project, in order to select the most useful methods for managing project trade-offs when resources are constrained.
Author: Logan Callen
Meredith, Jack R., Scott M. Shafer, and Samuel J. Mantel. 2017. Project Management: A Strategic Managerial Approach. 10th ed. Hoboken, NJ: John Wiley & Sons. ISBN-13: 9781119369097.