Chapter 8: Scheduling Resources and Costs

Chapter 8: Scheduling Resources and Costs

1. Resource Smoothing

   • If resources are adequate but the demand varies widely over the life of the project, it may be desirable to even out resource demand by delaying noncritical activities (using slack) to lower peak demand and, thus, increase resource utilization.

2. The consequences of failing to schedule limited resources are costly and project delays usually manifest themselves midway in the project when quick corrective action is difficult.

3. Up to now the start and sequence of activities has been based solely on technical or logical considerations.

4. The absence or shortage of resources can drastically alter technical constraints.

5. Resources are people, equipment, and material that can be drawn on to accomplish something. In projects the availability or unavailability of resources will often influence the way projects are managed.

6. Classification of a scheduling problem

   • Most of the scheduling methods available today require the project manager to classify the project as either time constrained or resource constrained.
     • Project managers need to consult their priority matrix to determine which case fits their project.
       • One simple test to determine if the project is time or resource constrained is to ask, “If the critical path is delayed, will resources be added to get back on schedule?” If the answer is yes, assume the project is time constrained; if no, assume the project is resource constrained.

7. Ease of demonstrating the allocation methods available requires some limiting assumptions to keep attention on the heart of the problem. The rest of the chapter depends entirely on the assumptions noted here.

   • splitting activities will not be allowed. This means once an activity is placed in the schedule, assume it will be worked on continuously until it is finished; hence, an activity cannot be started, stopped for a period of time, and then finished.
     • the level of resources used for an activity cannot be changed. These limiting assumptions do not exist in practice, but simplify learning.

8. Basically, all leveling techniques delay noncritical activities by using positive slack to reduce peak demand and fill in the valleys for the resources.

   • The downside of leveling is a loss of flexibility that occurs from reducing slack. The risk of activities delaying the project also increases because slack reduction can create more critical activities and/or near-critical activities. Pushing leveling too far for a perfectly level resource profile is risky. Every activity then becomes critical.

9. Because this project is declared time constrained, the goal will be to reduce the peak requirement for the resource and thereby increase the utilization of the resource.

10. When the number of people and/or equipment is not adequate to meet peak demand requirements and it is impossible to obtain more, the project manager faces a resource-constrained problem. Something has to give. The trick is to prioritize and allocate resources to minimize project delay without exceeding the resource limit or altering the technical network relationships.

11. Like leveling schedules, the limited resource schedule usually reduces slack, reduces flexibility by using slack to ensure delay is minimized, and increases the number of critical and near-critical activities.

12. Splitting tasks is a scheduling technique used to get a better project schedule and/or to increase resource utilization

    • Splitting can be a useful tool if the work involved does not include large start-up or shutdown costs—for example, moving equipment from one activity location to another.
      • The most common error is to interrupt “people work,” where there are high conceptual start-up and shutdown costs.

13. It is important to remember that, if resources are truly limited and activity time estimates are accurate, the resource-constrained schedule will materialize as the project is implemented—not the time-constrained schedule! Therefore, failure to schedule limited resources can lead to serious problems for a project manager.

14. The benefit of creating this schedule before the project begins leaves time for considering reasonable alternatives. If the scheduled delay is unacceptable or the risk of being delayed too high, the assumption of being resource constrained can be reassessed. Cost-time trade-offs can be considered. In some cases priorities may be changed

15. When making individual assignments, project managers should match, as best they can, the demands and requirements of specific work with the qualifications and experience of available participants.

16. Over time these people may grow to resent the fact that they are always given the toughest assignments. At the same time, less experienced participants may resent the fact that they are never given the opportunity to expand their skill/knowledge base

17. Organizations must develop and manage systems for efficiently allocating and scheduling resources across several projects with different priorities, resource requirements, sets of activities, and risks.

18. common problems encountered in managing multi-project resource schedules

    • 1.) Overall schedule slippage. Because projects often share resources, delays in one project can have a ripple effect and delay other projects. For example, work on one software development project can grind to a halt because the coders scheduled for the next critical task are late in completing their work on another development project.
      • 2.) Inefficient resource utilization. Because projects have different schedules and requirements, there are peaks and valleys in overall resource demands. For example, a firm may have a staff of 10 electricians to meet peak demands when, under normal conditions, only 5 electricians are required.
        • 3.) Resource bottlenecks. Delays and schedules are extended as a result of shortages of critical resources that are required by multiple projects. For example, at one Lattice Semiconductor facility, project schedules were delayed because of competition over access to test equipment necessary to debug programs. Likewise, several projects at a U.S. forest area were extended because there was only one silviculturist on the staff.

19. One major improvement in project management software in recent years is the ability to prioritize resource allocation to specific projects. Projects can be prioritized in ascending order (e.g., 1, 2, 3, 4, …), and these priorities will override scheduling heuristics so that resources go to the project highest on the priority list