My overall framework for product modelling work. It used to be called Artifact-Centred Modelling.
An overall framework, called Product Centred Modelling (PCM) is being developed. This framework divides the overall problem into a matrix arrangement using two axes of abstraction: by organizational structure on the one hand, and by levels of reasoning abstraction on the other.
PCM is based on separating design activities along two axes of abstraction:
|Functional Abstractions||Structural Abstractions|
|Designs & mfg systems||Products|
|Design processes||Product & Process Models|
|Eng Mgmt processes||Modeling languages|
The most recent published definition of PCM is given in [Sal95].
Goodness is often confused with quality, when in fact it is a more general concept (in engineering). Definitions of quality abound in the design engineering literature and they are mostly consistent at least in a general way. It is discussed as part of PCM because it is not only a concept applying to designed products and processes, but to the models, methodologies, theories, and logics that are used to formalize product models and processes.
To emphasize the difference between goodness and quality, consider that a good product is of both high quality and low cost. But high quality does not necessarily imply low cost per se, and vice versa.
But goodness is different, in that it makes no commitment to particular metrics the way that quality does. When one attempts to make something good, one implies (a) that there do exist characteristics that intentionally define good items, (b) that there is a method by which goodness is measured, and © that achieving goodness is always the fundamental goal of a development process.
Much of the research in logic, especially in areas like mereotopology and spatial reasoning, seems devoted to capturing “common sense” ideas about parthood, connection, and other relations between things. The problem is that common sense - the sense typical of the average person - is not reasonable in an engineering environment.
This is not to say that engineers require the most realistic, physically verifiable sense. Engineers do not (yet) care about quarks, or dark matter, or of spaces of more than 4 dimensions. Nonetheless, they require a far stricter perspective than that of the “common folk”. We are often interested in molecular and even atomic effects, and in maintaining a physical sense that takes into account the macroscopic behavior of materials that may be seen as counter-intuitive or bizarre by the common folk.
This “engineering sense”, then, sits somewhere between the rather lax sense of the common folk, and the very strict sense required by the natural sciences. Since engineering sense is not a guiding theme in the development of many of the foundations upon which this research builds, the Design Logic will have to re-interpret and, in some cases, re-develop components of the underlying logics, to remain consistent with engineering sense.