The Library
Critical chain identication and buffer sizing for efficient project management
Tools
She, Bingling (2020) Critical chain identication and buffer sizing for efficient project management. PhD thesis, University of Warwick.
|
PDF
WRAP_Theses_She_2020.pdf - Submitted Version - Requires a PDF viewer. Download (49Mb) | Preview |
Official URL: http://webcat.warwick.ac.uk/record=b3733314
Abstract
Project management organises about 30% of the world's economy (Hu et al., 2015b). Many recent projects apply critical chain project management (CCPM) methodology, which requires critical chain identification and design of project and feeding buffers. Critical chain identification is fundamental as it provides a baseline schedule without resource contentions. Subsequently, accurate sizing of the time buffers is essential, because too small buffers result in emergency procedures to prevent late delivery, whereas too large buffers result in uncompetitive bids and lost contracts. Previous research simply treats the former as a standard resource-constrained project scheduling problem (RCPSP) and predominantly focuses on the buffer sizing problem. The work typically results in excessive buffers and in critical chains being challenged by the insertion of feeding buffers, leading to inconsistent performance in project makespan estimation.
In this research, we start with an explicit definition for the problem of critical chain identification considering how to deal with resource contentions. In addition to the RCPSP method that avoids concurrent processing of tasks involved, three new methods that allow for concurrent processing of tasks via trade-off between time and cost/resource are proposed and represented in mathematical programming models, which are actually generalised RCPSPs and potentially provide shorter critical chains and CCPM schedules. Then, heuristics are proposed to solve these NP-hard models. Experimental analysis on wide-ranging real-life project data confirms the effectiveness of these methods and tests the validity of the proposed heuristics against benchmarks.
Given that the critical chain and baseline schedule are determined, we develop a new buffer sizing procedure based on analytical network decomposition. The procedure is implementable for any project network and offers logical advantages over previous ones. First, the size of a feeding buffer is determined from all associated noncritical chains. Second, the project buffer incorporates safety margins outside the critical chain by comparing feeding chains with their parallel critical counterparts. Computational testing on a case study of a real project and extensive simulated data shows that our procedure delivers much greater accuracy in estimating project makespan, and smaller feeding buffers. Furthermore, the resulting critical chain is never challenged. Additional benefits include delayed expenditure, and reductions in work-in-process, rework, and multitasking.
Then, an improved CCPM method is obtained by combining the critical chain identification and buffer sizing procedures. We conduct a numerical study on the time performance of the CCPM compared to traditional critical path methods, using diverse real-life project data and considering different scenarios of uncertainties and risk preferences. The results indicate consistent advantages of CCPM regarding short and accurate project makespan estimates. Comprehensive information of how each method performs in each scenario is also provided to help with the decision making of appropriate scheduling techniques for any specified project.
Overall, this research fundamentally improves the CCPM methodology to deliver efficient project schedules and provides clear guidelines for project managers to choose the right scheduling techniques for real-life projects.
Item Type: | Thesis (PhD) | ||||
---|---|---|---|---|---|
Subjects: | H Social Sciences > HD Industries. Land use. Labor Q Science > QA Mathematics > QA76 Electronic computers. Computer science. Computer software |
||||
Library of Congress Subject Headings (LCSH): | Project management, Computer networks -- Management, Buffer storage (Computer science), Scheduling | ||||
Official Date: | December 2020 | ||||
Dates: |
|
||||
Institution: | University of Warwick | ||||
Theses Department: | Warwick Business School | ||||
Thesis Type: | PhD | ||||
Publication Status: | Unpublished | ||||
Supervisor(s)/Advisor: | Chen, Bo ; Ceglarek, Darek | ||||
Sponsors: | University of Warwick. Warwick Business School ; China Scholarship Council | ||||
Format of File: | |||||
Extent: | xv, 120 leaves : illustrations | ||||
Language: | eng |
Request changes or add full text files to a record
Repository staff actions (login required)
View Item |