Mixed integer programming models for the synchronization of a project building planning with its supply chain

Abstract

A project consists of a set of activities coordinated by precedence relationships. When this activities have no needs of resources or the resources are unlimited, project management is easier and techniques like PERT(program evaluation and review technique)[1] or CPM (Critical Path Method)[1] can be used. The resource-constrained project scheduling problem (RCPSP) is one of the best known cumulative scheduling problems due to its combinatorial complexity, the interest of the operational research community, and to its numerous industrial applications. The basic RCPSP [2], [3] deals with scheduling activities subject to Finish-to- Start precedence constraints with zero time-lags and renewable resources under the minimum project completion time objective. The context of the present research is the industrialization of the process of thermal insulation of buildings by the outside. The idea is to manufacture in plants highly integrated big panels, that can be easily transported and then plugged on building faces. . The planning -issue we address here concerns- the possible synchronization of the project of a building renovation with the plant (or plants) that provide the panels. The novelty is to move from a “on the building site” make to order production, to a mass customization supply chain. Therefore, we are seeking for an homogenization of the renovation process to improve its efficiency in all technical senses but also organizational and economic. Objectives depend on the manager and his responsibilities in the supply chain. From a plant manager perspective, it can be the perfect synchronization of the plant production and the on-site assembly in order to avoid inventories. In the building project manager idea, it is usually to finalize the project by the minimal possible time allowed by the precedence relationships, and to minimize the cost of his on-site project. The differences with the classical RCPSP[4] is that, in this case, the resources to be considered are both renewable and non-renewable. Moreover the objective function is not only about to finish as early as possible, as issues such as the synchronization of the project become very important. Finally the issue is to provide a production planning that is compatible with the delivery of the project and the availability of resources both renewable and non-renewable. The former is the part of the problem on the supply chain perspective. The latter concerns the management of the load on nonrenewable resources, which is moved from the building site to the plants. Let consider the most general case we consider in this paper: one project of building with various suppliers with resource constraints. These external resources are independent. It means that every resource has one different supplier. But, it will be necessary to manage simultaneously the project on-site resources and partners-plant resources.