Managing variation: an industrial perspective on product line engineering

If nothing endures but change, then to make the products of our labor enduring, we must build them to accommodate change. If they cannot, they will be cast aside. Change can be thought of as occupying a time window: A solution needs to do something different a year from now, and then something different from that six months later, and so forth. An extremely interesting special case is when that time window shrinks to zero: Our solution needs to do and be a dozen different things right now. In many sectors, that special case turns out to be, in fact, the most common case. The so-called general case, where a single solution evolves over time, turns out to be a less interesting special case. This talk will explore the foundations for the field of product line engineering, which is the engineering of a family of systems that are similar but vary from each other. We will explore various techniques for handling this need, from the earliest to the most up to date, and show how the approaches transcend just software but apply across all engineering disciplines and all levels of an enterprise. Finally, we relate how this concept is being applied in industry today, and show where it is saving companies tens to hundreds of millions of dollars annually.