6 comments by 1 or more people

1. Indira Moreno

   I consider that the major difference between CIM and DM is that CIM was focused on Automatization of the information flow in order develop and manufacture products. DM contribute to this ideas of integration with validation, in the past simulation tools were used isolated from the information systems used for the product development, but with digital manufacturing are an important part of this processes and systems integration.

   11 Apr 2007, 02:09

2. Indira Moreno

   My conclusion:

   CIM in has focus on integrating the product data in order that everybody can work with the same information in a concurrent and collaborative way to achive objectives such as time to market reduction, cost reduction, errors reduction, etc…

   DM is concern with those objectives as well, but it also focused on validating that the development can actually work and be achieved, and that before any implementation or investment is made just by digital means.

   Thenfore DM can achieve further time to market reduction, costs reduction, errors reduction as the whole ‘system’ can be analyzed without making any physical test.

   11 Apr 2007, 03:54

3. Neil Davis

   I’m not sure I entirely agree with Indira’s view “that CIM was focused on Automatization of the information flow in order develop and manufacture products”. In the early days I observed that CIM efforts mostly resulted in the implementation of physical automation, where a wider than previous range of equipment was integrated under a single control regime. Often this was based on mini-computer hardware such as the DEC PDP-11 and VAX computers. The main issues during the 1980s were hardware interfacing – there being no universally accepted standards for networking let alone device level protocols – and reliability – often resulting in complicated and uncertain fault diagnosis, special parts, elaborate system restore procedures and lengthy downtime.

   The main information processing tasks were to manage the flow of execution for simple manufacturing process control e.g. move part from point A to point B via operating point C at which point apply machine instruction Z; and the higher level algorithms for scheduling jobs through the system e.g. choosing which job to perform next to meet some objective criteria.

   The high-point of early CIM was the evolution of Flexible Manufacturing Systems ( FMS ).

   I do not recall any significant progress in linking the engineering design process with manufacturing through CIM efforts at that time. Concurrent Engineering concepts hadn’t yet been accepted so engineers designed the product then passed it to manufacturing to make it; it was only at this latter stage that CIM got involved. Having said that, it may be that some researchers were thinking of liking these tools, I don’t know, but it wasn’t the focus of CIM in the 1980s.

   11 Apr 2007, 09:43

4. Neil Davis

   In response to Indira’s conclusion – I think that this is closer to the situation that has evolved since the mid to late 1990s. Whether this is a result of the widespread adoption of concurrent engineering – that brought into focus the process of new product introduction and recognised the inherent inter-relatedness of design and manufacturing engineering – and the subsequent development of CAD, first to include PDM and later PLM, or some other stimulus I’m not sure. I don’t think the impetus came from manufacturing however as ‘they’ have always been the subservient partner in most engineering companies during new product introduction.

   I agree that DM today in many peoples view is intimately bound up with validation through the use of simulation applications and that the validity of the models used and the time needed to build them can be significantly enhanced (quality and efficiency) through linking with the product data model.

   I would be interested to know whether you think this is all that DM is, can or will be?

   11 Apr 2007, 09:55

5. Indira Moreno

   I agree with you in that the early efforts of CIM were focus on physical automation, as the first step to move toward CIM is implementing FMS. Furthermore, companies at that time realized the need of being able to manufacture a wider range of products, that leaded to persue a manufacturing system that enable to produce different products in the same facility (flexibility). I consider that some of the factors that contributed to concentrate the efforts in physical automation is the fact that arround that time there were important technology developments that enabled the automation, and that vendors focused on developing robots, CNC, machining tools and other related technologies. By the contrary, I consider, that technologies to integrate CAD, CAM, CAPP were not fully developed and there were still problems to integrate those systems then companies didn’t focus that much on doing so.

   In what I don’t totally agree is that CIM doesn’t not attempted to integrate the desing with manufacture. In the early 1980s there was not a common understanding of what CIM was, there were several different definitions (some very different) one of those definitions focused on the implementation of automated manufacturing systems (perhaps your idea comes from that definition), this definition was one of the more broadely accepted but it was a very limited view of CIM and didn’t include the integration of desing in the manufacturing process. There were other definitions that focused in the integration of CAD, CAM and other manufacturing functions but they had it shortcomings as well.

   It was in the late 1980s, early 1990 that the definition of CIM was homogenated. It included no only technology to automate manufacturing systems and technology to support manufacturing activities but included other bussines initiatives as concurrent engineering. Concurrency was included as companies realized that being able to produce a wider range of products was not enough to compete, they need to be agile as well in to introduce new products faster to the market, and stay on the market.

   Although CIM included concurrent engineering I consider that the technology in CIM was still working as a serial process, thus it was hard to achieve the full potential of the concurrent thinking even if it was part of CIM philosophy.

   In contrast, in DM the technology is integrated in such a way that enable concurrency, the persons involved in the product and in the process design can have access to real time information and the collaboration is enhanced as tools enable communication. -> this partially answer the previews question.

   12 Apr 2007, 09:25

6. Neil Davis

   I guess you are right, my definition probably does emanate from my direct experience. I was working in Industry at the time and at that time perhaps those who were seeking to integrate design were mostly working in research. As an anecdote, the company I was working for in the mid 1980s had designed their new product family using a CAD package called CADAM (developed by Lockheed, sold to IBM and ultimately acquired by Dassault Systemes … its a small World). They had designed their manufacturing fixtures using the same CAD package, and their tooling but when they came to generate their CNC programmes they found that the resulting files were useless: the design engineers had used the CAD tool like an electronic drawing board with the result that although the geometry features appeared to meet, for example at edges, when viewed on screen or when printed they didn’t actually meet mathematically, so the NC commands failed to produce the required geometry. This is a simple and imperfect example but nevertheless illustrates just how far away industrial practice was from what people were thinking and I guess the same is true today and probably always will be.

   12 Apr 2007, 18:18