Posted by

Theory of Project Risk and Schedule Probability (Quantum Modeling)

Risk Track

Downloadable Files:



Reliable calculation of schedule probability as a function of risk remains an extremely important and unresolved problem of project management. It is well known that real project durations might differ from originally planned by a substantial factor of 30%-100%.

Existing methodology addresses the problem by establishing task distribution functions and con- ducting Monte Carlo simulations of milestone probability. These results fully depend on the ac- curacy of task distribution functions.

Another approach is quantum modeling of a milestone where all tasks “propagate” in time and compose a very short non-zero probability density function M(t) around milestone date. Function M(t) aggregates contributions of all reporting tasks and substantially enhances the analysis capabilities.

In practical applications, probability of schedule is predicted in comparison with other similar projects with known history, or relative to the “average” project in the given industry vertical.


Ilya Fishman
Dr. Fishman is a physicist with extensive background in the application of methods and techniques of modern physics to optical and solid state problems, as well as extending these techniques to the field of project management. After emigrating from Soviet Union in 1987 where he was with A.F. Ioffe Institute in Leningrad, he worked as Senior Scientist at Stanford Applied Physics Department in 1989-1999. From 1995 to 1997, he was consulting for Sprint’s Advanced Technology Lab in Burlingame before founding Optimight Communications, an ultra-long haul fiber optics transmission company, where he served as President and CTO in 1999-2002. In 2004, he founded Ibico with the purpose to advance methodology and accuracy of project planning, risks and cost estimates.

David Graham
Before coming back to the Air Force Cost Analysis Agency, David worked at NASA HQ’s in Washington DC from April 2003 – May 2008. Prior to his NASA assignment, he worked at the Aerospace Corporation for two years supporting the Intelligence Community Cost Analysis Improvement Group (IC CAIG). He began at the Space & Missile Systems Center (SMC), Los Angeles AFB, CA in Jan, 1979. He has held a variety of budget, cost performance, cost estimator, cost-risk and program analyst positions up to the present. His career has taken him from Los Angeles to Washington DC and back three times, finally coming back to where he started at SMC and living in the Hermosa Beach area. His work includes earned value analysis, cost estimating, cost-risk analysis, cost as an independent variable (CAIV), Activity Based Costing, aircraft modification financial analysis and space launch range pricing. Most recently, he is focusing on scenario-based discrete cost-risk assessment and analysis utilizing the likelihood vs consequence risk matrix and extending that qualitative analysis into more quantitative results expressed as statistical confidence levels. David is a SCEA Certified Cost Estimator and a present SCEA Board Member.