Resource Buffers in Critical Chain Project Management

  • Leonarda Valikoniene

Student thesis: Phd


Critical Chain Project Management (CCPM) is a relatively new method of scheduling. Whilst it has a number of advantages over traditional scheduling methods, it is still far from perfect. A literature review of the CCPM method, its shortcomings and suggestions for improvement is presented in this thesis. The review reveals that, in addition to other issues addressed, most researchers concentrate on the question of project and feeding buffer size. Issues concerning the resource buffer are ignored in the literature. This is a crucial gap in research, as resources are needed to perform tasks, and resource buffers protect the critical activities from the unavailability of resources. Although the original CCPM method treats resource buffers only as a notice or a 'wake-up call', the research in this thesis proposes to include resource buffers as time buffers with the assigned resources and cost. The research in this thesis provides a simulation methodology to answer the problem of resource buffer allocation and sizing. The simulation is performed on 3 projects, generated by RanGen software, each with the same characteristics of network order strength, resource strength and resource use. Three different buffer sizes and three different uncertainty levels are applied to the schedules. The analysis of simulation results demonstrates that no optimum resource buffer can be obtained for all projects in general. Each project, even with the same characteristics, behaves differently. Therefore the simulation methodology, developed and presented in the thesis, has to be applied to decide on the size of resource buffer in a specific project. The research outcomes demonstrate that resource buffers cannot be neglected and should be simulated using CCPM schedules, as they help to reduce the total project duration during execution. The decision whether to apply the resource buffer should also be based on financial analysis of the cost and benefits of inclusion.
Date of Award1 Aug 2015
Original languageEnglish
Awarding Institution
  • The University of Manchester
SupervisorMargaret Emsley (Supervisor) & Therese Lawlor-Wright (Supervisor)


  • Resource buffers
  • Scheduling
  • Project Management
  • Critical Chain

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