Current Status and Future Potential of the Research on Critical Chain Project Management


Mahdi Ghaffari and Dr. Margaret W. Emsley

University of Mancheste

Manchester, UK


 Critical Chain Project Management (CCPM) is a relatively new method which introduces a new mechanism for managing uncertainties in projects. A high number of studies on CCPM have been published and it seems it is now time for an extensive review. This study consults the CCPM literature in an inductive manner in order to answer the following questions: Is ongoing research being conducted on CCPM or has it lost its popularity among researchers? What have been the different approaches towards CCPM in the literature and what has each of them contributed to the knowledge area? What improvements have been made to the method since its introduction in 1997 and have these answered the critiques of the method? In what direction should future research be directed and what are the potential areas of CCPM for further development? The main aim is to describe the current status of research on CCPM and explore CCPM aspects that require more research. This study covers 140 journal and conference papers written on CCPM through an “exhaustive with selective citation” approach identified through online and reference searching. Those papers are categorised into six groups of introductory, critical, improving, empirical, case-reporting and exploiting papers, using the “hierarchical coding” method. As the result of this, the current status of research on CCPM is critically reviewed, themes are identified and 21 areas for future investigations are recommended that mostly need operational research analyses.

Keywords: Critical chain, Project scheduling, Literature review, project management.
JEL: O21, O22


Critical Chain Project Management (CCPM) was first introduced by Eliyahu Goldratt as a new method of managing projects at the International Jonah Conference in 1990 (Bevilacqua et al., 2009). It remained unexplored until he decided to repeat his success in writing “The Goal” business novel in 1984, this time with “Critical Chain” in 1997. In his book, Goldratt extended the principles of the Theory of Constraints (TOC) to project management. TOC was based on the principle that every system has a constraint that prevents it from reaching higher levels of performance and the only approach to improve the system performance is to enhance the capacity of that constraint. With regard to CCPM, this unique constraint in single project environments is the longest chain of activities in the project network, taking into account both activity precedence and resource dependencies (critical chain) and in multi-project environments is the resource impeding projects’ earlier completion. Goldratt (1984, 1997) provides a 5-step procedure for the process of ongoing improvement (identify the constraint, exploit the constraint, subordinate other non-constrained entities to the constraint, elevate the constraint, return to step one if the constraint is changed). CCPM also suggests estimating activity durations to their 50% probability of being completed on time and consider a buffer (project and feeding buffers) at the end of each chain of activities to allow for uncertainties. There are also some other buffers, namely resource buffer, drum buffer, capacity buffer and cost buffer. Some other characteristics are that it is completely against multitasking, does not consider activity due dates and schedules non-constraint activities to their latest start.

CCPM is not a holistic approach towards managing projects and is more a scheduling method addressing schedule-related aspects of projects. It only includes human aspects in terms of scheduling activities and not related to leadership, project governance and communication. These aspects should be addressed through TOC philosophy or Lean principles, as explained in the TOC Handbook (Cox and Schleier, 2010). As it is outside the scope of this study to explain in more detail the principles of CCPM, readers are encouraged to read the CCPM classic book by Leach (2014) for a comprehensive explanation.


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Editor’s note: Second Editions are previously published papers that have continued relevance in today’s project management world, or which were originally published in conference proceedings or in a language other than English. Original publication acknowledged; authors retain copyright. This paper was originally presented at the 4th Scientific Conference on Project Management in the Baltic States, University of Latvia, April 2015. It is republished here with the permission of the author and conference organizers.



About the Authors


pmwj38-Sep2015-Ghaffari-AUTHOR1Mahdi Ghaffari

The University of Manchester


Mahdi Ghaffari
is a PhD candidate at The University of Manchester undertaking his research on resource availability issues in Critical Chain Multi-Project Management environments and their effects on sizes of buffers in such environments. He has achieved a Bachelor’s degree (BSc) in Industrial Engineering and Master of Science in Management of Projects. His experience includes working as a project manager of maintenance projects for about three years. He is also certified as PRINCE2 Practitioner by OGC based in the UK and PMP by PMI based in the USA.  Mahdi can be contacted at [email protected].


pmwj38-Sep2015-Ghaffari-AUTHOR2 EMSLEYDr. Margaret Emsley

The University of Manchester




Dr. Margaret Emsley is a civil and structural engineer who joined what was then UMIST in 1986. Previously she had carried out research at Loughborough University and worked as an engineer for Tarmac Construction. She was involved in setting up the MSc in Construction Project Management in 1987 and has contributed to the teaching of many courses at both undergraduate and postgraduate level. She has supervised 5 PhD students and over 150 MSc students and has 7 current PhD students. She is currently Chair of the School Board and Programme Director of the MSc Management of Projects (including the four routeways: Commercial Project Management, Construction Project Management, Engineering Project Management and IT Project Management).  Prof Emsley can be contacted at [email protected].