Reducing rigidity by implementing closed-loop engineering in adaptable design and manufacturing systems

Traditional engineering design and manufacturing systems function as an arrangement of individual engineering activities with predefined rigid interfaces. In contrast, agile design and manufacturing engineering strategies require flexible processes that can be adapted rapidly for fast response to dynamic market demands without compromising the cost and quality of the product. In an attempt to address this deficiency of traditional systems, this paper proposes and explores a novel model of product lifecycle management (PLM) in which instead of studying engineering activities exclusively with respect to a temporal variable, the processes are deliberately managed to form closed loops of two or more activities with respect to two independent dimensions: time and rigidity. The model is referred to as closed-loop engineering (CLE). The CLE model eliminates the need to specify solid interfaces between the engineering activities. Instead, flexible interfaces are generated by real-time analysis of respective actions and the reactions between them. In order to study the performance and efficiency of CLE, case studies in three different levels of sub-activity, inter-activity and infra-activity loops in the fields of design, manufacturing and inspection are presented. The implementation results revealed that individual closed loops of different engineering activities in the product development process can significantly enhance the quality of the final products. Also, the flexibility of the interfaces between the activities results in adaptable production systems.