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 A DSM-Based CCPM-MPL Representation Method for Project Scheduling under Rework Scenarios

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Guofeng Ma ◽  
Ming Wu ◽  
Keke Hao ◽  
Shanshan Shang
Keyword(s):  
Information Flow ◽  
Project Scheduling ◽  
Project Schedule ◽  
Design Structure ◽  
Flow Interactions ◽  
Critical Chain Project Management ◽  
Management Method ◽  
Representation Method ◽  
Relationship Of ◽  
Critical Chain

Rework risks caused by information flow interactions have become a major challenge in project scheduling. To deal with this challenge, we propose a model integrating the critical chain project management method, design structure matrix method, and max-plus method. Our model uses a start-to-start relationship of activities instead of the traditional finish-to-start relationship, which also allows overlaps between activities. We improve the accuracy of the rework safety time in two ways: (1) the overall overlapping effect is taken into consideration when calculating the rework time of an activity arising from the information flow interaction of its multiple predecessors overlapped with it; (2) the rework time arising from activity overlaps, the first rework time, and the second rework time are calculated as components of the rework safety time in our model, while the last one is ignored in traditional methods. Furthermore, the accuracy of time buffers is improved based on the improved rework safety time. Finally, we design the max-plus method to generate project schedules and appropriately sized time buffers. The empirical results show that the project schedule generated by the proposed method has a higher on-time completion probability, as well as more appropriately sized project buffers.

Predicting Penetration of the Project Buffer Time of Critical Chain Project Management (CCPM) Using a Linear Programming Approach

2020 ◽  
Vol 9 (2) ◽  
pp. 143-151
Author(s):  
Milind Jagtap
Keyword(s):  
Linear Programming ◽  
Project Management ◽  
Resource Constraints ◽  
Programming Model ◽  
Botanical Garden ◽  
Programming Approach ◽  
Project Schedule ◽  
Buffer Time ◽  
Critical Chain Project Management ◽  
Critical Chain

Managing the disruptions in projects is a challenging task for project managers. In this respect, critical chain project management (CCPM) has been considered as a promising methodology in expediting projects. However, the effectiveness of this methodology is often lost in search of optimal use of project buffers to hedge against delays occurring in the critical chain. The more critical chain activity gets delayed, the greater is the likelihood of penetration of project buffer time. The resource constraints of critical chains have been considered as a major determinant of project buffer penetration. Although a project buffer is provided to protect the critical chain, to keep the CCPM project schedule competitive, it is the priority of the project manager to minimize the blatant consumption of project buffer time by multiple critical chain activities. Historically, resource constraints within the critical chain have been associated with penetration of project buffer time. The literature suggests that the productivity of resources deployed in the critical chain can predict the penetration of project buffer time. Based on the premise that delays are omnipresent and unavoidable but predictable, this research aims to consider the post-facto measures of delays instead of pre-facto measures. Pre-facto measures are resources productivity and resources availability while post-facto measures are the compensation paid by the client and the cost of liquidity damages incurred by the contractor. It is assumed that pre-facto measures are convertible into post-facto measures. A linear programming model is formulated and tested using the case of Botanical Garden Construction Project in Pune city. Sensitivity analysis revealed that the propensity of project buffer penetration on a critical chain varies with the compensation matrix. Varieties of scenario are developed and the optimal solution is validated with the case study.

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.

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