Increasing Complexity of Artifacts and the Response of Manufacturing Firms: Design of control systems and integration of mechanism, electronics, and software (Japanese)

In this paper I investigate the issue of increasing complexity of artifacts today from the viewpoint of design theory. To be more specific, I interpret products supplied to markets by firms to be "artifacts" (things that are designed), and analyze various factors that make them complex or simplified, and the actions of firms. In general, when customer specifications and social constraints (e.g. environmental and safety measures) become more sophisticated and complex it becomes more difficult to address them by modularization, and products tend to become more integral and more complex. In order to handle this increasing complexity of products/artifacts, firms respond with multiple supplemental approaches. (1) First of all, although the modularization of product architecture is considered to be very effective for countering increasing complexity, in cases of products in which thorough modularization is difficult to achieve for certain reasons, firms address this issue by (2) the conventional method of enhancement of trial-and-error product-development capabilities through the inspection of functions through trial manufacture and by the supplementary combination of factors such as (3) digital trial-and-error development utilizing development support IT (such as three-dimensional CAD) (4) quality engineering that searches efficiently for structural designs that have fewer functional disparities, and (5) electronic control systems that guarantee the realization of targeted functions in real time. (6) Additionally, in cases in which electronic control systems themselves become complicated, approaches employed include model-based development to support the electronic design CAD that constitutes them or (7) the design of embedded software. Thus it can be seen that the development of electronic control systems is vital for making complex artifacts function properly. Especially in the case of products such as automobiles, in which there remain large numbers of structural components (mechanical) of controlled systems, resulting in mechanism/electronics/software co-development, it is necessary to have mutual coordination between mechanical design for controlled systems and electronic and software design for control systems. However, for historical and other reasons the aforementioned three-design systems tend to have different design cultures, for example as to whether they place more emphasis on functional design or structural design, or on logical symbols or physical symbols. Also, in the case of automobiles, which are in essence artifacts in controlled systems, between designers there is a mechanism>electronics>software power balance. In order to counter this segregation tendency and promote the integration of mechanism/electronics/software it is extremely important to seek to achieve integration at the upstream level of development, doing so by refining the expression of artifacts in natural language that lies at the source of design activities, and seeking new IT to promote teamwork design of mechanism/electronics/software at the upstream development stage.