PERT 21: Fitting PERT/CPM for use in the 21st century

Abstract More than half a century after the debut of CPM and PERT, we still lack a project scheduling system with calibrated and validated distributions and without requiring complex user input. Modern decision support systems (DSS) for project management are more sophisticated and comprehensive than PERT/CPM. Nonetheless, in terms of stochastic analysis, they show insufficient progress. PERT 21 offers a radically different stochastic analysis for projects, based on relevant and validated theory. Operationally, it is sophisticated yet simple to use. It is designed to enhance existing DSS, and thus it can be implemented without sacrificing the investment already made in project management systems. Finally, regarding the important sequencing and crashing models developed under CPM, PERT 21 permits their adaptation to stochastic reality.

[1]  Robert E. D. Woolsey.  The Fifth Column: The PERT That Never Was or Data Collection as an Optimizer , 1992 .

[2]  Robert C. Ash,et al.  Towards holistic project scheduling using critical chain methodology enhanced with PERT buffering , 2008 .

[3]  L. Fenton.  The Sum of Log-Normal Probability Distributions in Scatter Transmission Systems , 1960 .

[4]  Gunnar Blom,et al.  Statistical Estimates and Transformed Beta-Variables. , 1960 .

[5]  Richard J. Schonberger,et al.  Why Projects Are “Always” Late: A Rationale Based on Manual Simulation of a PERT/CPM Network , 1981 .

[6]  Ofer Zwikael,et al.  Prediction of project outcome The Application of statistical methods to earned value management and earned schedule performance indexes , 2009 .

[7]  C. E. Clark.  The Greatest of a Finite Set of Random Variables , 1961 .

[8]  Kenneth R. Baker,et al.  Principles of Sequencing and Scheduling , 2018 .

[9]  Avraham Shtub,et al.  Project Management: Processes, Methodologies, and Economics , 1994 .

[10]  Dan Trietsch.  Optimal feeding buffers for projects or batch supply chains by an exact generalization of the newsvendor result , 2006 .

[11]  Jerome D. Wiest.  Some Properties of Schedules for Large Projects with Limited Resources , 1964 .

[12]  Glenn Butts,et al.  The Joint Confidence Level Paradox: A History of Denial , 2009 .

[13]  Ofer Zwikael,et al.  Project Management for the Creation of Organisational Value , 2011 .

[14]  Luis G. Vargas,et al.  Fitting the Lognormal Distribution to Surgical Procedure Times , 2000, Decis. Sci..

[15]  A. R. Klingel,et al.  Bias in Pert Project Completion Time Calculations for a Real Network , 1966 .

[16]  Jan Van Damme,et al.  Project scheduling under uncertainty survey and research potentials , 2002 .

[17]  Luis G. Vargas,et al.  Surgeon and Type of Anesthesia Predict Variability in Surgical Procedure Times , 2000, Anesthesiology.

[18]  Erik Demeulemeester,et al.  Critical Chain Project Scheduling: Do Not Oversimplify , 2002 .

[19]  Dan Trietsch,et al.  Balancing Stochastic Resource Criticalities Hierarchically for Optimal Economic Performance and Growth* , 2009 .

[20]  D. Malcolm,et al.  Application of a Technique for Research and Development Program Evaluation , 1959 .

[21]  Lyn C. Thomas,et al.  Experts' estimates of task durations in software development projects , 2000 .

[22]  A. Tversky,et al.  Judgment under Uncertainty: Heuristics and Biases , 1974, Science.

[23]  Dan Trietsch.  Why a Critical Path by Any Other Name Would Smell Less Sweet? , 2005 .

[24]  James E. Kelley,et al.  Critical-path planning and scheduling , 1899, IRE-AIEE-ACM '59 (Eastern).

[25]  Dan Trietsch.  The effect of systemic errors on optimal project buffers , 2005 .

[26]  Bajis M. Dodin,et al.  Bounding the Project Completion Time Distribution in PERT Networks , 1985, Oper. Res..

[27]  T. Raz,et al.  A Critical Look at Critical Chain Project Management , 2003, IEEE Engineering Management Review.

[28]  Charles E. Clark,et al.  Letter to the Editor—The PERT Model for the Distribution of an Activity Time , 1962 .

[29]  Richard M. Van Slyke,et al.  Letter to the Editor---Monte Carlo Methods and the PERT Problem , 1963 .

[30]  James E. Kelley,et al.  Critical-Path Planning and Scheduling: Mathematical Basis , 1961 .

[31]  William R. King.  Network Simulation Using Historical Estimating Behavior , 1971 .

[32]  Erik Demeulemeester,et al.  Proactive policies for the stochastic resource-constrained project scheduling problem , 2011, Eur. J. Oper. Res..

[33]  Mansooreh Mollaghasemi,et al.  The Project Assessment by Simulation Technique , 2007 .

[34]  Kenneth R. Baker,et al.  Modeling activity times by the Parkinson distribution with a lognormal core: Theory and validation , 2012, Eur. J. Oper. Res..