An Approximation for the Activity Duration Distribution, Supporting Original PERT
نویسندگان
چکیده
The Program Evaluation and Review Technique (PERT) has been widely used as a tool for project management. In PERT analysis the activity time distribution is assumed to be a beta distribution, and the mean and variance of the activity time are estimated. The activity mean and variance are very useful to find the expected project duration and variance of the critical path. By generalizing the assumption on parameters in original PERT an approximation for the mean and variance of a PERT activity duration is proposed and by comparison with numerical case it is shown that the mean and variance of PERT activity duration in this proposed method and original PERT are approximately equal. This supports that the original PERT estimates are valid in generalized case also. Mathematics Subject Classification: 90B10, 90B15, 90B50, 90C06
منابع مشابه
Combination of Approximation and Simulation Approaches for Distribution Functions in Stochastic Networks
This paper deals with the fundamental problem of estimating the distribution function (df) of the duration of the longest path in the stochastic activity network such as PERT network. First a technique is introduced to reduce variance in Conditional Monte Carlo Sampling (CMCS). Second, based on this technique a new procedure is developed for CMCS. Third, a combined approach of simulation and ap...
متن کاملExpected Duration of Dynamic Markov PERT Networks
Abstract : In this paper , we apply the stochastic dynamic programming to approximate the mean project completion time in dynamic Markov PERT networks. It is assumed that the activity durations are independent random variables with exponential distributions, but some social and economical problems influence the mean of activity durations. It is also assumed that the social problems evolve in ac...
متن کاملA New Approach to Approximate Completion Time Distribution Function of Stochastic Pert Networks
The classical PERT approach uses the path with the largest expected duration as the critical path to estimate the probability of completing a network by a given deadline. However, in general, such a path is not the most critical path (MCP) and does not have the smallest estimate for the probability of completion time. The main idea of this paper is derived from the domination structure between ...
متن کاملEstimating the Mean and Variance of Activity Duration in PERT
The traditional PERT (Program Evaluation and Review Technique) model uses beta distribution as the distribution of activity duration and estimates the mean and the variance of activity duration using “pessimistic”, “most likely” and “optimistic” time estimates proposed by an expert. In the past several authors have modified the original PERT estimators to improve the accuracy. In this paper, on...
متن کاملExpected Duration of Dynamic Markov Pert Networks
In this paper, we apply the stochastic dynamic programming to approximate the mean project completion time in dynamic Markov PERT networks. It is assumed that the activity durations are independent random variables with exponential distributions, but some social and economical problems influence the mean of activity durations. It is also assumed that the social problems evolve in accordance wit...
متن کامل