Production planning and project scheduling for engineer-to-order systems- case study for engineered wood production

Small companies that prefabricate parts for the construction industry in the context of engineer-to-order (ETO) systems, often encounter production issues as they usually do not systematically optimise their planning. In this paper, a production planning method for a multi-project ETO system is proposed. Four optimisation models testing combinations of three objectives are proposed. The main objective present in all models is cost reduction. The other objectives considered are minimising project finish time and minimising set-up time of a bottleneck station. The models are applied in a case study with an engineered wood production firm considering fifteen construction projects over a period of forty weeks. Two scenarios for adding long and complex projects and projects with medium length and complexity are also tested to provide a decision support tool in the project acceptance phase. This article contributes to the scientific literature by providing four production scheduling models which integrate a multi-objective production scheduling approach in a multi-project context for the prefabrication of ETO parts in construction. Furthermore, the research applies the models to a real case which highlights empirical issues that had not been entirely explored in current literature.