New multi-objective methods to solve resource-constraint multi-project scheduling problems in integrated ERP-APS systems

This paper presents a new scheduling model and methods to solve multi-project scheduling problems considering strict resource constraints and multiple objective functions simultaneously. The solution approach is based on an integration of enterprise resource planning system (ERP) and an advanced planning and scheduling application (APS). An ERP system software component defines a set of projects with their details (activities, due dates, processing times, precedence constraints, etc.) and the available resources with their capabilities and real constraints. The user can specify many objective functions and their priorities. The goal of this scheduling problem type is to create a detailed execution plan that meets all the hard constraints and gives a near optimal compromised solution from objective functions point of view. In real execution environments, more than one projects may run in parallel, and they may require the same resources. For example, projects may produce the standard type of products, and they use the same manufacturing resources. In different decision-making situations, dynamic priorities may be defined for projects or activities to express the relative importance of items. The paper focuses on modeling and solving of multi-objective multi-project scheduling problems, and we present the integration of ERP and APS systems.