BUS606: Operations and Supply Chain Management

Research literature can sometimes seem to present a rather theoretical view of models which may not fully reflect how they are used in practice. In reality, companies do not use any one model or modelling approach exclusively. Many fragmentary models coexist in a company and their contents can overlap to varying degrees. Models vary in terms of the approach or notation used, the scope and level of detail, and the level of fidelity. There is often no organised framework in which most models used within a company are positioned, and if such a framework exists, it may not be appropriately utilised by everyone. Browning views this fragmentation of process models as "extremely undesirable", suggesting that it may contribute to difficulties in organising and coordinating a process, with the consequence that information may not flow to the right people in timely fashion.

Although undesirable, this situation is, for now, usually the reality. People need to consider multiple DDP models to find information about their processes, or may gain that information by asking their colleagues and perhaps building their own models. The value of a model often lies in helping people to frame and analyse a complex situation - models must be interpreted by bringing them together with knowledge of the application context, and simulated in the minds of their users to understand their implications and guide decisions. There is an opportunity for further research to examine the properties of this system of interactions between models and their stakeholders in a company, and how those properties might affect the coordination and performance of the DDP.

The different types of model are used in different ways. Procedural models are typically evolved in companies to meet their specific needs. In particular, most firms customise the stage-gate model to their processes and the customised version will be familiar to most employees, although in a multi-year program, it may not provide much guidance for day-to-day activity. Other procedural models such as the PDCA cycle are typically associated with particular improvement initiatives in a company, and depending on the success of the particular initiative might be accepted to a greater or lesser degree. The main value of these models in practice is arguably to assist in communicating methodological insights to a large number of employees, and as such, clarity of exposition may be one of their most important characteristics.

In terms of analytical models, many large companies have developed a set of process maps which, in some sectors such as aerospace and automotive, are required by regulatory authorities to demonstrate that the company can explain how its products are developed and show that required process steps such as validation activities are appropriately performed. The effort to keep this information up-to-date in the face of changing processes and technology can be significant and practice can deviate substantially from what these models portray. Other analytical process models used in practice are developed as an early step in the process design or improvement initiatives to generate understanding of the process in focus. Such models, often using notations such as BPMN, are essentially isolated, because the initiatives that generate them are often very limited in scope. As a result, they may not continue to deliver benefit once those initiatives are finished. Some analytical models such as task network simulation, system dynamics, and DSM may find limited application in a company but are often limited to trials driven by the personal interest of individuals, while others such as agent-based models and rule-based models remain mostly in the research domain.

Finally, abstract and MS/OR models are arguably not intended for direct application in industry and are probably not often used in that context, although the insights developed from them may be of value to practitioners.