Stochastic Based Pre-emptive Planning and Scheduling

This paper describes a significant revision to the Concurrent Engineering (CE) methodology that enables a shortened project completion time. Under the CE methodology, sequential tasks can only be performed as such. We introduce a method for starting sequential tasks concurrently using a pre-emptive approach. Where there are a, suitably small, finite number of possible alternative subsequent tasks, we propose that a more agile approach is to begin work on these alternative subsequent tasks concurrently to the preceding task, sharing the resource needed for the subsequent task amongst the different alternatives. Further, where the probability for each alternative task is known, we demonstrate that by setting the resource allocation equal to the probabilities of each outcome, it is possible dynamically allocate resources to minimise the expected completion of the overall project. A simple classically sequential two task case study is developed and analysed to illustrate this method. The paper concludes by revisiting the original assumptions and discussing how resource efficiency is traded off for minimising project completion time.