Integrating Discrete-Event Simulation into the Manufacturing System Development Process A Methodological Framework

Today, after more than four decades of presence in the manufacturing industry, we can conclude that simulation as a technology has become extremely powerful, that simulation software – although not entirely adequate – still appears very capable, and that methodologies for performing simulation projects are reasonably well-developed and documented. Turning to the context and scope of this thesis, we see that discrete-event simulation (DES) can be applied to a wide range of manufacturing system development activities. As evidence of what this technology can do, successful cases from various industrial sectors abound. In brief, DES use can have significantly positive impacts on the quality, cost, and time aspects of manufacturing system development (MSD) and the product realization process (PRP). Despite a seemingly rosy picture, however, this thesis argues that several problems associated with the adoption and use of DES still exist in industry. First, a majority of companies do not use simulation at all, and many of these do not have enough belief in what simulation can do for their organizations to even consider using it in the future. Second, companies that use simulation do not seem to have realized the full potential of this technology. In the terminology of this thesis, they have not fully integrated simulation into their MSD process. Often, simulation is used on a one-shot basis only, troubleshooting specific problems such as bottlenecks, usually in late stages of the manufacturing system life-cycle, or as a stand-alone tool, both of which reflects a low level of simulation integration, a concept introduced here. Despite that reasons for this modest and non-integrated use of simulation in the manufacturing industry have been less than satisfactorily explored (empirical studies in particular are scarce), some conclusions can be drawn as to the nature of these reasons. In brief, these have been found to be attributed to reductionist views on and unstructured approaches to DES integration. At the same time, it seems that academia is not fully addressing the issues needed to overcome this situation. Simulation research on integration aspects often deals with specific system and application integration, or what can be referred to as functional issues, such as integrating and connecting simulation to other systems and tools, rather than structural, hierarchical, and procedural