Life-Cycle Properties of Engineering Systems: The Ilities

Abstract

In the epoch of engineering systems, the focus has changed. As we discussed in chapter 3, their evolution over long lifetimes is a significant aspect of large-scale complex systems. Understanding and working with engineering systems requires attention to properties that have long time exposure. Attention to side effects and the context that establishes ground rules and constraints within which systems operate is crucial, as these factors are part of the systems' very essence. The Importance of Not Simply " Working " The first automobiles were largely motorized versions of the horse-drawn carriages that preceded them. But as the artifact improved and began to work in more demanding operating environments—at higher speeds, at night, in adverse weather—new subfunctions, beyond the primary function of the car, became important. Over time, inventors responded by adding windshields to cars to protect the eyes and mouths of drivers from bugs, windshield wipers to ensure visibility in the rain, and headlights so drivers could see in the dark. Lots of other improve-ments were made over the years, perhaps more than most contemporary drivers know. It wasn't long before it was became to address some side effects of driving automobiles. For example, the first cars were equipped with 8799_004.indd 65 6/16/2011 7:30:21 PM