Calculation of the auxiliary buffers time with regard to the robustness of the construction schedule to disruption

Abstract

The literature offers numerous proposals for calculating the project buffer, located at the end of the critical chain. However, the structure of construction schedules, often consisting of several dozen or several hundred tasks, requires planning a larger number of buffers, also located on the critical chain. The article proposes an original method of dividing the duration of one buffer located at the end of a protected chain (e.g. a project buffer) into several auxiliary buffers, protecting individual fragments of this path. The basis of the algorithm that calculates their size is to take into account the robust of protected task paths before the deadline for their completion is disrupted. As a measure of robust understood in this way, the ratio of the buffer size to the sum of the variance of the task duration of the protected draft was applied. The criterion of searching for the optimal time division into several buffers was to maximize the minimum robust of all analyzed paths. The application of the proposed optimization model is illustrated on the example of a specific construction schedule.