The amount of time needed to build and tune models is lower than the amount of time needed for heuristic rules. More accurate explanations of the results can be provided to the user. . Model-based reasoning is more complex from the conceptual and computational point of view. Building models is a complex activity. Thus, different models can be built for a device, according to the modeling choices and assumptions that are made.
Different models can be adequate for different tasks.
Qualitative Models aim to capture the fundamental behaviour of a system or mechanism into a computer model, while suppressing much of the detail. Methods such as abstraction and approximation are often used to build models based on qualitative rather numerical aspects of a system. Qualitative Reasoning is an inferring technique using qualitative models to derive new knowledge of, and gain insight into a physical technical system in a specific subject area. It can generate an approximate solution to a given engineering problem. It applies production systems in a qualitative manner and uses other knowledge based methods such as constraint networks, ontology etc during its reasoning process.