Since 1980 efforts to improve the productivity of simulation modeling in manufacturing have yielded the range of COTS discrete event simulation packages (CSPs) that are used today by engineers and analysts to investigate complex, dynamic process-based systems found in commerce, health, manufacturing and supply chains. It is true that there are many different types of system that might be called COTS packages. However, this work concerns itself with systems that fall under the discrete event simulation paradigm, i.e. simulated models of systems that change state at discrete points in time (scheduled events) or as a result of state changes (conditional events). These state changes typically represent entities (documents, patients, parts, trains, etc.) that pass through networks of queues and workstations (work queuing at a desk in an office, patients waiting to see a doctor, parts buffered for machining, trains waiting at a station, etc.) CSPs support activities such as model building, experimentation, animation, visualization and reporting. There are currently around 20 of these commercially available .

It is important to note that the model/CSP technology is a fixed point. Virtually every engineering faculty has some course on simulation modeling that uses one or more CSPs. Engineers and analysts use these CSPs to build and maintain simulation models. These CSPs therefore represent a significant investment. Additionally, users of these CSPs are not software engineers - they are simulation modelers. There is evidence to show that it is highly likely that any major changes to their methodology and technologies will result in the non-adoption of these proposed products. It is therefore a major consideration of our work that any interoperability products that are developed are highly transparent in nature.