Towards multi-project simulation of a lean production system for customized apartment buildings

In typical construction projects, general contractors devote significant resources to coordinate the work of multiple subcontractors. Subcontractors and general contractors interests are frequently misaligned, and they strive for local optima. In particular, subcontractors balance the demands of different projects as they search to deploy their resources most productively. The problems are exacerbated where customization, such as tailoring of apartments by clients, disrupts workflow. Separation of standard (structure, public spaces) from customized work (apartment interiors) may drastically improve the production system. Separation represents a fundamental change to industry practice. Evaluating separation requires experimentation on a multi-project scale; agent-based simulation is the only practical research method. Simulations of single project systems showed that Lean interventions improve productivity, cash flow and project duration. Recent work with agent-based simulation with two projects and eight subcontractors has shown that the standard/customized work separation provides additional advantages. Future work will extend the simulations to multiple projects.