Resource conflicts
(→Resource-constrained project scheduling problem (RCPSP)) |
(→Basic form of the RCPSP / Basic concept of RCPSP / Standard RCPSP) |
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==Basic form of the RCPSP / Basic concept of RCPSP / Standard RCPSP== | ==Basic form of the RCPSP / Basic concept of RCPSP / Standard RCPSP== | ||
| + | This problem pertains to a project consisting of J activities labeled j=1,…,J. The duration of each activity j is represented by dj, which signifies that once an activity begins, it must be completed without interruption. Generally, there are technological requirements that establish precedence relationships between the activities, which are denoted by sets of immediate predecessors Pj. This means that an activity j cannot commence until all its predecessors (i∈Pj) have been completed. | ||
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| + | Furthermore, these precedence relationships can be depicted in the form of a network. To perform each activity, a certain quantity of resources is required, with the resources being considered renewable due to full capacity being available in each period. A total of K types of renewable resources are available, labelled k=1,…,K, with Rk being the constant amount of resource available at the start of each period for resource k. In each period where activity j is processed, rjk units of resource k are required. Two additional activities, j=0 and j=J+1, represent the beginning and end of the project, respectively, and are both considered dummy activities with a processing time and resource consumption of zero. All parameters in the problem are assumed to be deterministic, definite, and non-negative integers. The objective of the problem is to determine the start time (Sj) for activities j=0,1,…,J+1 in such a way that the project's completion time is minimized. | ||
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| + | Given the vast differences encountered in practice, researchers have modified the original form of the RCPSP over time. Moreover, it has been demonstrated that the RCPSP problem is classified as a strongly NP-hard problem. As a consequence, different solutions are employed based on the variations in the fundamental assumptions (Habibi et al., 2018). | ||
==Resource Constraints== | ==Resource Constraints== | ||
Revision as of 19:47, 19 February 2023
Developed by Thordis R. Ragnarsdottir
Contents |
Overview
Relevance of Project Scheduling / Resource Conflicts
Broader context of the problem for example:
- Importance of efficient project scheduling
- The challenges of resource allocation
- Performance Criteria (Potential reference: Herroelen et al., 1996)
- The trade-offs between project completion time, resource utilization, and cost
Potential Reference (Chapter 1): (Demeulemeester & Herroelen, 2006)
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The allocation of limited resources over a period of time is the primary focus of scheduling and sequencing in project management. Scheduling pertains to the determination of when specific activities should take place, while sequencing deals with the arrangement of these activities in a particular order. Research on how to optimally allocate scarce resources over time has been a significant area of interest since the inception of operations research in the mid-1950s (Herroelen et al., 1996).
The effective and accurate management of extensive projects is purported to result in successful project implementation, increased revenues, and reduced costs and lost profits. Scheduling is therefore, a crucial responsibility of project management, but it has become increasingly challenging due to resource limitations and the need to account for precedence relationships. As a result, project scheduling is a widely recognized and fundamental issue that researchers have extensively studied from different angles. The development of standard solutions for this issue has been a major focus in the field of project management.
Resource-constrained project scheduling problem (RCPSP)
- Discuss various project scheduling techniques, such as Gantt charts, Critical Path Method (CPM), and Program Evaluation and Review Technique (PERT)
- Explain how each technique works and its advantages and disadvantages
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The problem of project scheduling involves determining the time required to complete a project's activities to achieve a specific objective. Early research on project scheduling focused on describing activities solely in terms of their duration, leading to the development of methods like the critical path method (CPM) and program evaluation and review technique (PERT), which account for precedence relationships between activities. However, treating precedence relationships as independent is an unrealistic assumption, prompting the introduction of constraints to better model their impact. One notable constraint is resource availability, which is a pervasive issue in project scheduling and is commonly referred to as the Resource-Constrained Project Scheduling Problem (RCPSP).
Basic form of the RCPSP / Basic concept of RCPSP / Standard RCPSP
This problem pertains to a project consisting of J activities labeled j=1,…,J. The duration of each activity j is represented by dj, which signifies that once an activity begins, it must be completed without interruption. Generally, there are technological requirements that establish precedence relationships between the activities, which are denoted by sets of immediate predecessors Pj. This means that an activity j cannot commence until all its predecessors (i∈Pj) have been completed.
Furthermore, these precedence relationships can be depicted in the form of a network. To perform each activity, a certain quantity of resources is required, with the resources being considered renewable due to full capacity being available in each period. A total of K types of renewable resources are available, labelled k=1,…,K, with Rk being the constant amount of resource available at the start of each period for resource k. In each period where activity j is processed, rjk units of resource k are required. Two additional activities, j=0 and j=J+1, represent the beginning and end of the project, respectively, and are both considered dummy activities with a processing time and resource consumption of zero. All parameters in the problem are assumed to be deterministic, definite, and non-negative integers. The objective of the problem is to determine the start time (Sj) for activities j=0,1,…,J+1 in such a way that the project's completion time is minimized.
Given the vast differences encountered in practice, researchers have modified the original form of the RCPSP over time. Moreover, it has been demonstrated that the RCPSP problem is classified as a strongly NP-hard problem. As a consequence, different solutions are employed based on the variations in the fundamental assumptions (Habibi et al., 2018).
