This talk explores three concepts of system in engineering: systems theory, systems approach, and systems engineering. They are exemplified in three dimensions of engineering: science, design, and management. Unifying the three system concepts is the idea of function: functional abstraction in theory, functional analysis in design, and functional requirements in management. Signifying what a system is for, function is a purposive notion absent in physical science, which aims to understand nature. It is prominent in engineering, which aims to transform nature for serving the wants and needs of people.
The engineering system concepts are compared to the notion of system as a seamless web in postmodern technology studies. As Friedrich Nietzsche remarked: “Being profound and seeming profound. – Those who know that they are profound strive for clarity. Those who would like to seem profound to the crowd strive for obscurity. For the crowd believes that if it cannot see to the bottom of something it must be profound. It is so timid and dislikes going into the water.” [The Gay Science § 173]

Systems in everyday life, technology study, and engineering
Systems are everywhere in our daily discourse, from the solar system to home entertainment systems, from water treatment to national security systems. Railway networks and electric power grids are systems, so is the internet and the world wide web. Then there are the more intangible political, social, and financial systems. “The system works,” people say when things go smoothly; “the system fails,” when troubles strike. The commonsense notion of system is familiar: the system is a whole comprising interrelated parts with significant complexity; the system is not merely the sum of its parts. There seems to be no restriction on whether the related parts are animate of inanimate, people of things, hardware or software, concrete or abstract. Nevertheless, their interrelations, although complex, should be susceptible to some rational understanding. A muddled mess or an incomprehensible chaos is at best a failed system, if one at all.
“System” is a buzzword in technology studies, although its significance beyond the commonsense notion is obscure. Systems are said to be heterogeneous, but the heterogeneity often turns out to be a jumbling miscellany and the system a sausage with medley indifferentiable stuffing. Perhaps the most prominent notion of “system” is expressed by the metaphor of a “seamless web.” Introduced by Thomas Hughes, the prime promoter of “systems thinking,” it conveys the notions of holism, perfection, and resistance to analysis. It is popular in postmodern scholarship, which is hostile to rationality.
Systems are central to engineering. Engineers are responsible for designing and building transportation, communication, and other systems that operate in the real world. Their systems concepts are clear. Here I explore three: systems theories, systems approach, and systems engineering. None comes close to a seamless web. The systems approach in engineering, with its emphasis on analysis and modularity, is opposite to the anti-analytic postmodern “systems thinking.”

Systems versus seamless webs
In his book Science of the Artificial, Herbert Simon gives the parable of two watchmakers, each designs a watch with a hundred parts. In the first design, the hundred parts are so thoroughly interrelated that the watch totally falls apart if any one is removed. The watch is expensive because it must be assembled in one breath and cannot be repaired by replacing parts. The second watch has similar performances, but its parts are grouped into ten modules, which can be replaced if defective. Because it is simple to assemble and easy to modify, the second watchmaker is able to offer his products at a lower price and drive the first watchmaker out of business.
Simon’s first watch design is akin to a seamless web; his second design, an engineering system. A seamless web is good if