In the United States, rigorous models are also referred to as “first principle based”. These models form a technical mechanism with an exact scientific methodology.
For example, it is possible to represent and simulate a process engineering process such as an air separation unit, sulfuric acid or phosphate plant by physically and kinetically simulating all of the plant’s known processes and reactions one by one using characteristics, differential equations and balance equations.
Rigorous models have the advantage that processes simulated in this way can be understood very clearly, but their implementation is very expensive – too expensive for most processes. For this reason, cost-conscious companies are increasingly counting on new modeling methods, such as neural networks, and stay away from using rigorous approaches. In some cases, such as training simulators, it is however impossible to avoid use of this technology, since usually there is no other system which could be used to train the simulator.
Conventional solutions for rigorous modeling are typically programmed. This makes it virtually impossible to achieve a knowledge transfer between developer and user. The developer becomes indispensable and the company is dependent on him.
Rigorous models implemented using APC Professional® are graphically configured and documented. This way, error searches are easy, and the models can be well understood even by non-computer specialists.