Workspace planning in construction: non-deterministic factors

Workspace interferences and collisions occurring on construction jobsites are products of unexpected spatiotemporal overlaps of resources. They affect the project performance and can create an unsafe environment. Current practices for workspace planning adopt a linear/mechanistic approach in modeling, which ignores uncertainties occurring during construction operations. Those methods do not account for the emergent behavior of crews, irreversibility of decisions made in the case of interferences, and bifurcation of those decisions over the project lifecycle. This paper presents the results of qualitative and quantitative analysis of the significance of such gaps. A software tool was developed to model workspaces probabilistically and detects interferences from 4D models. The impact of uncertainties on interference magnitudes was evaluated based on available models, and an industry survey was conducted accordingly. The results suggest that compounding effects of uncertainties may significantly affect the frequency and volume of overlapped workspaces in a project (volumes can increase for as much as 220%, for a 40% deviation in the inputs). Our findings also propose crew attributes for formulating a bottom-up approach, capable of capturing crews' interactions and predicting their decision when managing collisions.