Effect of Network's Morphology and Merge Bias Correction Procedures on Project Duration Mean and Variance

Many authors have discussed the source of errors in PERT networks as follows: Uncertainty in the mean and variance calculations of (a) activity's durations and (b) total project duration, and its related distributions. Different corrections formulas and procedures were proposed. In the other hand, there's an existing risk of delay related to the project morphology, in terms of the number of activities, shape and complexity of the project network. However, the relationship of network's morphology and the uncertainty of the whole project's duration are poorly studied. In this research, a set of project networks with different morphology were generated and several methods available in literature (original PERT included) were used to estimate the parameters (mean and variance) of total project duration, then comparing them to the Monte Carlo Simulation as a representation of the reality, and the best and most accurate method(s) were chosen.