TABLE OF CONTENTS Of the 3 components of the triple constraint time, cost and scope cost is one of the most difficult to control. As changes occur, adjustments and contingency plans can be established to maintain time and scope objectives. Costs however are nearly always negatively affected as schedules slip or scope increases. In addition, if unforeseen costs are incurred, adjusting or absorbing these changes to stay on budget is extremely difficult.
In order to counteract these forces, it is important to ensure that any changes to cost are agreed upon, that changes to cost are identified quickly and that any changes are managed as they occur.
PMI advocates the use of EVT to integrate scope, schedule and resources. EVT promotes common understanding by using common metrics and it helps assess the magnitude of cost variations quickly. It also accurately reflects the variations associated with schedule and costs separately. EVT provides a consistent methodology for measuring performance across projects.
In Chapter 6 on time management, crashing was discussed as a strategy to compress the project schedule without reducing project scope. Crashing requires using alternative strategies for completing project activities (such as using outside resources) for the least additional cost. Figure 7-4 on the following page recalls the schedule compression table in Figure 6-4, but with the cost component added.
| Possible Opportunity | Schedule | Cost | Risk |
|---|---|---|---|
| Reduce Activity W 3 days by hiring an expert | Reduce 3 days | Increase $2,000 for the 3 days |
