On path correlation and PERT bias

On path correlation and PERT bias

Most studies of project time estimation assume that (a) activity times are mutually independent random variables; many also assume that (b) path completion times are mutually independent. In this paper, we subject the impact of both these assumptions to close scrutiny. Using tools from multivariate analysis, we make a theoretical study of the direction of the error in the classical PERT method ...

Iterative Converging Algorithms for Computing Bounds on Durations of Activities in Pert and Pert-Like Models

Pert 21

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 ...

Interdiction Games on Markovian PERT Networks

In a stochastic interdiction game a proliferator aims to minimize the expected duration of a nuclear weapons development project, while an interdictor endeavors to maximize the project duration by delaying some of the project tasks. We formulate static and dynamic versions of the interdictor’s decision problem where the interdiction plan is either pre-committed or adapts to new information reve...

Dynamic interdiction games on PERT networks

In a PERT network interdiction game one player tries to get a project, represented as a PERT graph, finished as quickly as possible by allocating resources, expediting the project’s tasks and choosing between different technologies to use. At the same time a second player aims to maximally delay the project’s completion date by carefully choosing which tasks to disrupt. We develop a novel conti...