A decentralized and pull-based control loop for on-demand delivery in eto construction supply chains

Engineer-To-Order (ETO) process chain types with a successive installation on-site are common in plant building and the construction industry. Usually, the core processes Engineering, Fabrication and Installation are disconnected, which creates high levels of Work in Progress (WIP) and long lead-Times. Furthermore, up to date information about the construction progress, as prerequisite for an on-demand delivery of ETO-components is always difficult to obtain. Usually, to prevent a lack of material on-site, costly intermediate storages are used, which extend the delivery time. Well-known approaches in research, like the Last Planner System (LPS) or the Location Based Management System (LBMS), increase collaboration on-site and improve the reliability of construction schedules, but have a limited impact on synchronizing the supply chain to the construction progress. The approach presented in the paper describes how off-site and on-site production can be coupled, to reach short construction lead-Times without wastefully intermediate storages. A first IT-prototype, based on "Industry 4.0" principles, was implemented and tested in an Italian medium-sized ETO construction supplier.