Quantitative assessment of budget sufficiency and resource utilization for resource-constrained project schedules

� 2016 American Society of Civil Engineers. Assessment of budget sufficiency and resource utilization for a resource-constrained project schedule is crucial to ensure practical feasibility of the schedule and successful delivery of a construction project. This paper proposes a quantitative assessment approach for characterizing budget sufficiency and resource utilization for a resource-constrained project schedule in an objective fashion. The budgeted unit, deployed unit, and scheduled unit in connection with a resource-constrained project schedule are first defined. Next, two budget sufficiency metrics, named the budget sufficiency index and budget sufficiency variance, are defined for measuring the sufficiency of control budget in terms of deploying resources to execute the project schedule with resource constraints. In addition, two resource utilization metrics, termed the resource utilization index and resource utilization variance, are defined for indicating utilization efficiency of deployed resources based on the schedule. The proposed metrics are applied to objectively assess multiple alternative resource-constrained project schedules derived from various approaches, including a practical scheduling approach (Primavera P6) and resource scheduling optimization techniques recently developed from in-house research. A textbook example and a refinery plant turnaround project are used to demonstrate the effective application of proposed metrics on alternative resource-constrained schedules. It is concluded that (1) resource scheduling optimization techniques outperform Primavera P6 in terms of budget sufficiency and resource utilization thanks to streamlining resource supply limits and shortening project duration by optimization; and (2) a significant portion of the idled resource time in the Primavera P6 schedule turns into extra contingency in the optimized schedule that can be reserved against any work unforeseen or unknown during the planning stage.