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

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.

Author(s):  
Suherman Suherman

Penelitian ini dilakukan untuk membuat perencanaan proyek jalan SMK IT Payakumbuh yang diharapkan tidak seperti proyek sebelumnya, dimana terjadi ketidaksesuaian antara perencanaan dan pelaksanaannya. Hal ini dikarenakan ada beberapa pekerjaan yang overlapping. Oleh karena itu dibuat penjadwalan ulang dengan menggunakan metode Critical Project Management(CCPM). Dari data primer dan sekunder diolah dengan software microsoft project 2007. Metode ini menghilangkan waktu aman (Safety Time) dan menggantinya dengan waktu penyangga (Buffer Time). Penambahan buffer time dengan menggunakan metode cut and paste yaitu menambahkan project buffer separuh durasi rantai kritis (critical chain) pada akhir rantai dan meletakan feeding buffer dengan separuh durasi aktivitas ke aktivitas pada rantai tidak kritis (non critical chain). Hasil dari penelitian bahwa apabila saat proyek berjalan tidak terdapat perubahan-perubahan maka proyek dapat diselesaikan selama 147 hari kalender. Apabila terjadi ketidaksesuaian, maka buffer time dapat dikonsumsi sebesar 10 minggu dan total penyelesaian proyek selama 197 hari kalender, waktu aman untuk proyek pembangunan jalan SMK IT Payakumbuh ini.


2019 ◽  
Vol 11 (24) ◽  
pp. 7229
Author(s):  
Guofeng Ma ◽  
Jianyao Jia ◽  
Tiancheng Zhu ◽  
Shan Jiang

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.


Author(s):  
Jose Finocchio Junior ◽  
Marcelo Ramos Martins

The present study discusses the adequacy of the Critical Chain Project Management Method (CCPM) — also known as the Critical Chain Method — for scheduling projects involving shutdowns on oil platforms, as such projects involve decision-making processes under risk conditions. The CCPM is based on the Theory of Constraints and aims at providing more precise and more clearly focused control instruments than those traditionally used in the Critical Path Method (CPM). The CCPM also indicates the best moments to act and where and how the action should be directed. The hypothesis underlying the research is that the CCPM portrays, more adequately than the CPM, the uncertainty that exists in a platform shutdown. This characteristic also makes it possible to draw up a schedule that is both more realistic and more challenging, as it addresses the goal of causing less interruption of production. On the basis of this hypothesis, the two main questions that oriented the entire investigation were: 1) Is the CCPM suitable for scheduling the shutdown of an offshore oil platform and, 2) What advantages might it have over the traditional methods in use? To answer these questions the authors reviewed the existing bibliography on the topic and made direct on-site observations during an actual shutdown. In addition, interviews were held with a number of specialists in the area using qualitative approaches, namely, semi-structured interviews, focus groups, and action research.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tarek Salama ◽  
Ahmad Salah ◽  
Osama Moselhi

Purpose The purpose of this paper is to present a new method for project tracking and control of integrated offsite and onsite activities in modular construction considering practical characteristics associated with this type of construction. Design/methodology/approach The design embraces building information modelling and integrates last planner system (LPS), linear scheduling method (LSM) and critical chain project management (CCPM) to develop tracking and control procedures for modular construction projects. The developed method accounts for constraints of resources continuity and uncertainties associated with activity duration. Features of proposed method are illustrated in a case example for tracking and control of modular projects. Findings Comparison between developed schedule and Monte Carlo simulation showed that baseline duration generated from simulation exceeds that produced by developed method by 12% and 10% for schedules with 50% and 90% confidence level, respectively. These percentages decrease based on interventions of members of project team in the LPS sessions. The case example results indicate that project is delayed 5% and experienced cost overrun of 2.5%. Originality/value Developed method integrated LPS, LSM and CCPM while using metrics for reliability assessment of linear schedules, namely, critical percent plan complete (PPCcr) and buffer index (BI). PPCcr and BI measure percentage of plan completion for critical activities and buffer consumption, respectively. The developed method provides a systematic procedure for forecasting look-ahead schedules using forecasting correction factor Δt and a newly developed tracking and control procedure that uses PPCcr and BI. Quantitative cost analysis is also provided to forecast and monitor project costs to prove the robustness of proposed framework.


2012 ◽  
Vol 50 (No. 2) ◽  
pp. 71-76 ◽  
Author(s):  
T. Šubrt

The aim of the paper is to present one possibility of how to model and solve a resource oriented critical path problem. As a starting point, a single criteria model for critical path finding is shortly mentioned. Lately, more criteria functions for this model are defined. If any project task uses more resources for its completion, its duration usually depends on only one of them – other resources are not fully used. In here defined multiple criteria approach, these dependencies are not assumed. Each criteria function is derived from a theoretical task duration based on a number of units of only one resource and on its importance. Using either linear programming model with aggregated criteria function or simple Excel calculation with Microsoft Project software support, a so-called compromise critical path can be found. On this path, some resources are overallocated and some are underallocated but the total sum of all underallocations and all overallocations is minimized. All resources are used as effectively as possible and the project is as short as possible too.


2019 ◽  
Vol 12 (2) ◽  
pp. 423-443 ◽  
Author(s):  
Octaviano Rojas Luiz ◽  
Fernando Bernardi de Souza ◽  
João Victor Rojas Luiz ◽  
Daniel Jugend

PurposeThe purpose of this paper is to analyze the state of the art in Critical Chain Project Management (CCPM), outlining the CCPM literature to date, in an effort to guide future studies.Design/methodology/approachThe paper is based on a bibliometric analysis using Scopus and Web of Science databases. The authors identified the principal journals, articles and authors regarding the research theme, as well as the authors elaborated co-citation and co-occurrence network maps to support the analysis.FindingsThe authors described five co-citation clusters: Fundamentals of Critical Chain, Scheduling, Operations Research, Multi-project and Network, and General Project Management. The most frequently occurring keywords were: “project management,” “critical chain,” “scheduling” and “theory of constraints.” Observing the distribution, the expression “project management” occupied a central position, connecting two other clusters, represented by the keywords “scheduling” and “critical chain.” The authors proposed an evolutive framework for the CCPM state of the art in three stages, according to the most frequent topics identified: Conceptual, Deepening of Applications and Methodological Maturity.Originality/valueThis research adopts a systematic approach based on bibliometric tools, which allows a more rigorous organization of the literature. Co-citation and keyword co-occurrence maps provide evidence of how the main themes in CCPM relate. Besides, the presented historical framework allows new research in CCPM to be directed to the most recent topics of interest that have gaps to be explored.


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