Facility layout design with simulation-based optimization : A holistic methodology including process, flow, and logistics requirements in manufacturing

Abstract: Adaptability and flexibility are becoming key concepts in manufacturing. Today manufacturing companies often have to deal with random disruptive events, which necessitates significantly more complex manufacturing systems. Mass customization (manufacturing customized products with mass production efficiency) has also considerably increased the complexity of facility layouts, that is, the physical arrangement of the different aspects required to create products in a factory. Design and improvement of facility layouts is considered a major industrial problem as it affects so many aspects of business. Even in industrialized countries with a long manufacturing history, it is common to find facility layouts that lack optimized flows of materials and products. The main reason for this state of affairs is usually a lack of long-term planning, commonly due to continuous changes and adaptations of the production systems in the layout. These problems are exacerbated by today’s shortened product life cycle.Simulation and optimization are well suited to improve complex manufacturing systems in which several events occur at the same time with unpredictable situations. Thus this thesis aims to investigate how simulation and optimization, and their combination – called simulation-based optimization – can support the redesign and improvement process for existing facility layouts. A literature review shows there is a gap in the field relating to a holistic approach to optimizing facility layouts taking into account production processes and internal logistics. “Holistic” as used here refers to the consideration of the processes and flows occurring in the facility layout, namely machining, assembly, and internal logistics. The aim of this thesis thus includes proposing a holistic methodology based on discrete-event simulation to optimize processes, flows, and internal logistics related to the facility layout.A methodology is defined as a logical set of methods, and in this thesis the methodology has been developed using a case study method with a design and creation strategy. This approach has been successful in identifying and overcoming both theoretical and empirical challenges in simulation-based optimization of facility layout design. The methodology was evaluated using functional resonance analysis method and industrial case studies, and it has proven to be effective for optimizing facility layouts. These results can thus serve as a guideline for engineers and staff involved in this type of layout project, and as a guideline for managers and stakeholders to support strategic decisions.