Method to Assess the Match between Clients’ Input and Decoupling Points in Customized Building Projects

Abstract

Clients’ input (i.e., design drawings and specifications containing clients’ desired changes) is a key resource for task completion often missing in customized building projects, leading to waste such as additional movement, increase in work in progress, rework, stoppages, and delays. Such waste can be potentially reduced by postponing the moment in which such input is first needed [i.e., the decoupling point (DP)]. This paper proposes a simulation-based method to quantify the probability of having clients’ input according to production plans using the line-of-balance technique. The method is applied to two sets of plans to assess the effect of four variables (cycle time, batch size, work structure, and construction start time) on such probabilities. Work structure and construction start time were found to be the main variables affecting such probabilities. Nonetheless, preliminary results (considering a uniform probability distribution for clients’ input) indicate a minimal probability of having clients’ input according to production plans even for the most favorable plan (late construction start, DP in the last work package, short cycle time, and large batch size). This means that altering these variables is not sufficient to ensure the availability of clients’ input and other approaches are needed to support a good flow.