scheduling

Resource-constrained project scheduling involves the construction of an activity timetable, i.e. the determination of a start and finish time for each project activity, respecting the precedence relations and the limited availability of the renewable resources, while optimizing a predefined scheduling objective (see “Resource constrained project scheduling: What is my scheduling objective?”). In this article, the scheduling objective is assumed to be the minimization of the total duration (or lead time) of the project, which often is a standard scheduling objective option in commercial software tools.

Activities require renewable resources during their execution which are limited on a periodic basis (see “Resource types: Renewable and consumable resources”). In practice, activities need resources during their execution that are often limited in availability. In this article, the connection between the resource requirements of activities and the limited availability of these resources is discussed along the following topics:

It is a wise and generally accepted management principle to put a focus on the constraining or limiting factor of a system that determines the system’s goal. In project management and scheduling, the scheduling objective is the objective during the construction of a project baseline schedule.

Project scheduling is the act of constructing a timetable for each project activity, and differs in complexity due to the presence of renewable resources with limited availability. In this article, three important aspects of scheduling will be discussed, as given along the following lines:

The calculation of costs is an important aspect of project scheduling and control. In this section, two main types of costs are discussed, each consisting of two subtypes. The total activity cost consists of the sum of all subtype costs, as will be explained in this article. The two main types are as follows:

The Project Scheduling Game (PSG) is an IT-supported simulation game that illustrates the characteristics of scheduling a real-life project with discrete time/cost trade-offs in the project activities as described in this article. The project is based on a sequence of activities for a large real-life project at a Belgian company. The participant (manager) of the game has to construct a dynamic project schedule for the discrete time/cost trade-off critical path method. By allocating nonrenewable resources (i.e. money) to a particular activity, the manager decides about the duration and corresponding cost of each network activity. The manager schedules the project with the negotiated project deadline in mind, focusing on the minimization of the total project cost. 

The Critical Path Method (CPM) is a project scheduling technique to analyze and represent the tasks involved in completing a given project. It incorporates a trade-off between an activity’s duration and cost and relies on concepts similar to the program evaluation and review technique (PERT, see “The Program Evaluation and Review Technique (PERT): Incorporating activity time variability in a project schedule”).

PERT is a well-known and widely used project scheduling technique used to create an activity timetable taking variability activity durations into account. It relies on principles borrowed from statistics such as the central limit theorem and the normal distribution (see “The Program Evaluation and Review Technique (PERT): Incorporating activity time variability in a project schedule”).

The Program Evaluation and Review Technique (PERT) is a project scheduling technique to analyze and represent the tasks involved in completing a given project. It incorporates activity duration variability and relies on similar concepts as the critical path method (CPM, see “The Critical Path Method (CPM): Incorporating activity time/cost trade-offs in a project schedule”).