Supporting Flexibility in an Assembly System through Product Design

Increasing customer demands for product variety in conjunction with the short lifecycle of products has caused manufacturing companies to introduce a wide range of products by accommodating flexibility. An assembly system is an essential part of the manufacturing system from both cost and time perspectives. Hence, the shift towards flexibility in manufacturing companies highlights the significance of establishing flexible assembly systems and designing products that are closely aligned with them. Despite its significance, however, the flexible assembly system concept and its requirements for product design have not been clearly defined in research and from a practical point of view. Most research on flexible assembly systems has mainly approached either the design or the balancing and scheduling issues of these systems, whereas only a few studies have briefly defined the flexible assembly system they focused on, without further specifying the characteristics of a flexible assembly system and its requirements for product design. Taking that into account, the objective of this work is to provide a framework that contributes to the understanding of the concept of flexibility in an assembly system and its requirements for product design. In order to fulfil the objective, four empirical studies combined with literature reviews have been conducted. The empirical studies, a multiple-case study and three single-case studies, investigate the definition of flexibility in an assembly system as well as the requirements that a flexible assembly system imposes on product design. Through its findings, this research provides a definition of flexibility in assembly systems that mainly revolves around volume, mix and new product flexibility. In addition, six constituents of a flexible assembly system have been identified: adaptable material supply, versatile workforce, increased commonality, standardised work content, integrated product properties and strategic planning. Furthermore, three requirements of a flexible assembly system for product design are defined, which, if fulfilled, reduce the complexity created by product variety and consequently support flexibility in the assembly system. Accordingly, to increase the understanding of the concept of flexibility in an assembly system and its requirements for product design, a four-staged framework is suggested. The proposed framework deals with the activities related to the concept and the development of a flexible assembly system and is expected to be received by assembly practitioners as a link between assembly and product design teams in the product realisation process. Future research can further validate the framework in practice.