Fuzzy critical chain method for project scheduling under resource constraints and uncertainty

2008 ◽  
Vol 26 (6) ◽  
pp. 688-698 ◽  
Author(s):  
Luong Duc Long ◽  
Ario Ohsato
Keyword(s):  
Project Scheduling ◽  
Resource Constraints ◽  
Critical Chain

Fuzzy Activity Network Method for Project Scheduling Under Resource Constraints

2007 ◽  
Vol 11 (8) ◽  
pp. 914-921
Author(s):  
Luong Duc Long ◽  
◽  
Ario Ohsato
Keyword(s):  
Genetic Algorithm ◽  
Project Scheduling ◽  
Fuzzy Numbers ◽  
Resource Constraints ◽  
Project Schedule ◽  
Project Duration ◽  
Activity Network ◽  
Decision Variables ◽  
Network Method ◽  
Critical Chain

In this article, a fuzzy activity network method is developed for project scheduling under resource constraints. Trapezoidal fuzzy numbers are used for estimating uncertain durations of activities, and then these fuzzy numbers are replaced by suitable crisp durations for project scheduling under resource constraints. In the next step, the critical chain is identified for determining the project duration, and uncertainties associated with activities are addressed by using feeding/project buffers to protect the project schedule from disturbances. For minimizing project duration, the proposed method considers both the suitable crisp durations and the start times of activities as decision variables. Hence, a new procedure based on genetic algorithm and priority heuristics is also developed for efficiently determining these decision variables. Furthermore, the method also considers selecting the best possible relationships between activities to minimize project duration. The proposed method using buffers makes it possible to improve project scheduling under resource constraints.

scholarly journals Scheduling Optimization of Prefabricated Construction Projects by Genetic Algorithm

2021 ◽  
Vol 11 (12) ◽  
pp. 5531
Author(s):  
Linlin Xie ◽  
Yajiao Chen ◽  
Ruidong Chang
Keyword(s):  
Project Scheduling ◽  
Construction Projects ◽  
Resource Constraints ◽  
Construction Project ◽  
Engineering Application ◽  
Project Schedule ◽  
Scheduling Optimization ◽  
Implementation Method ◽  
Traditional Construction ◽  
Construction Project Scheduling

Prefabricated buildings are the direction of the future development of the construction industry and have received widespread attention. The effective execution of prefabricated construction project scheduling should consider resource constraints and the supply arrangement of prefabricated components. However, the traditional construction resource-constrained project scheduling implementation method cannot simultaneously consider the characteristics of the linkage between component production and on-site assembly construction. It cannot also fully adapt to the scheduling implementation method of the prefabricated construction projects. It is difficult to work out a reasonable project schedule and resource allocation table. In order to determine the relevant schedule parameters that can reflect the actual construction situation of the prefabricated building and meet the scheduling requirements of the prefabricated project, this study proposes a prefabricated construction project scheduling model that considers project resource constraints and prefabricated component supply constraints. Additionally, it improves the design of traditional genetic algorithms (GAs). Research results of the experimental calculation and engineering application show that the proposed project scheduling optimization model and GA are effective and practical, which can help project managers in effectively formulating prefabricated construction project scheduling plans, reasonably allocating resources, reducing completion time, and improving project performance.

scholarly journals A Critical Design Structure Method for Project Schedule Development under Rework Risks

2019 ◽  
Vol 11 (24) ◽  
pp. 7229
Author(s):  
Guofeng Ma ◽  
Jianyao Jia ◽  
Tiancheng Zhu ◽  
Shan Jiang
Keyword(s):  
Resource Constraints ◽  
Project Schedule ◽  
Management Tools ◽  
Simulation Methodology ◽  
Schedule Management ◽  
Critical Design ◽  
Design Structure ◽  
Activity Sequence ◽  
Impact Area ◽  
Critical Chain

In order to overcome the difficulty in quantifying rework by traditional project schedule management tools, this study proposes an innovative method, namely improved Critical Chain Design Structure Matrix (ICCDSM). From the perspective of information flow, the authors firstly make assumptions on activity parameters and interactions between activities. After that, a genetic algorithm is employed to reorder the activity sequence, and a banding algorithm with consideration of resource constraints is used to identify concurrent activities. Then potential criticality is proposed to measure the importance of each activity, and the rework impact area is implicated to indicate potential rework windows. Next, two methods for calculating project buffer are employed. A simulation methodology is used to verify the proposed method. The simulation results illustrate that the ICCDSM method is capable of quantifying and visualizing rework and its impact, decreases iterations, and improves the completion probability. In this vein, this study provides a novel framework for rework management, which offers some insights for researchers and managers.

scholarly journals Critical Chain Project Scheduling: Do Not Oversimplify

2002 ◽  
Vol 33 (4) ◽  
pp. 48-60 ◽  
Author(s):  
Willy Herroelen ◽  
Roel Leus ◽  
Erik Demeulemeester
Keyword(s):  
Project Management ◽  
Project Scheduling ◽  
Critical Review ◽  
Buffer Management ◽  
Direct Application ◽  
Theory Of Constraints ◽  
Management Literature ◽  
Critical Chain

Critical chain scheduling/Buffer management (CCS/BM)—the direct application of the theory of constraints (TOC) to project management—has received much attention in project management literature. There still is controversy over the merits and pitfalls of the CCS/BM methodology. This paper focuses on the fundamental elements of CCS/BM logic and pinpoints some intricacies that are not commonly referred to in the available literature. The authors’ analysis is based on a critical review of the relevant sources and experimentation with both commercial CCS/BM software and an internally developed CCS/BM-based tool.

A new project scheduling approach for improving multi-product multi-period production planning problems

2008 ◽  
Vol 222 (11) ◽  
pp. 1517-1527 ◽  
Author(s):  
S Noori ◽  
M Bagherpour ◽  
F Zorriassatine ◽  
A Makui ◽  
R Parkin
Keyword(s):  
Production Planning ◽  
Project Scheduling ◽  
Resource Constraints ◽  
Simulation Analysis ◽  
Analytical Models ◽  
Hybrid Solutions ◽  
Demand Fluctuations ◽  
Feasible Solutions ◽  
Operational Criteria ◽  
Planning Problems

The problem of matching production levels for individual products to demand fluctuations during multiple periods is known in the production planning literature as the multi-product multi-period (MPMP) problem. Linear programming (LP)-based solutions have been extensively reported in this respect. MPMP problems are commonly solved by using either analytic or simulation methods. More recently, hybrid solutions consisting of both analytical models and simulation analysis have been proposed where some operational criteria, e.g. the order of visit to machining centres, are taken into account. In this paper, results related to some of the literature based on hybrid solutions are used as the initial feasible solutions and then examined in the context of project scheduling by considering the influences of resource constraints. After converting the MPMP to a project network problem and assigning resources to activities and consequently levelling the resource profiles, it is discovered that machine utilization can be further improved by applying unused machine capacities. A LP model is therefore developed in order to maximize feasible production rates over all the production planning periods. The proposed approach results in improvements on the results of earlier hybrid solutions reported in the literature. Finally, three different planning problems are suggested for further applications of the proposed approach in the context of manufacturing environments.

Sign in / Sign up

Export Citation Format

Share Document