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

Guofeng Ma,Shanshan Shang,Keke Hao,Ming Wu,Chiara Bedon

doi:10.1155/2021/8878308

Abstract

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.

Highlights

Rework is defined as “the unnecessary effort of redoing a process or an activity implemented incorrectly the first time.” [1] Regarded as inevitable and epidemic in projects [2], rework has become a major impediment that adversely affects project performance
Accurate rework safety times of activities were calculated by factoring in rework time arising from activity overlaps, the first rework time, and the second rework time
Time buffers were determined with the root square error method (RSEM) considering the rework risk. e refined max-plus method was utilized to transform the logic ties, rework relationships, and other parameters of the activity into simple matrix operations, and such parameters are uniformly calculated by the maxplus method to realize the effective scheduling of the project

Summary

Introduction

Rework is defined as “the unnecessary effort of redoing a process or an activity implemented incorrectly the first time.” [1] Regarded as inevitable and epidemic in projects [2], rework has become a major impediment that adversely affects project performance. Many studies have shown the impact of rework risks on cost overrun and project delay. Love investigated 161 construction projects in Australia and concluded that rework was the main cause of overrun cost, which can reach 52% increased cost on average [3]. A study by Barber et al reported that rework costs can be as high as 23% of contract values [4]. Hwang et al surveyed 381 projects in Singapore and found that more than 80% of corporations and 59% of projects have experienced client-related rework, resulting in a cost increase of 7.1% and a schedule delay of 3.3 weeks on average [5]. Considerable research studies have explored the causes of rework as it significantly impacts project performance

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