Misleading architecting tradeoffs [DVD hard-disk architecture tradeoff analysis method]

A DVD hard-disk recorder case study shows how system architects can fall prey to ill-founded qualitative reasoning, which can lead them to favor unsupported tradeoffs that are based on incorrect assumptions. A tradeoff assumes that an improvement in one dimension negatively affects others. Sound, valid tradeoffs do exist, but not every decision calls for one. A bold improvement in one dimension can improve other dimensions of the design space, even though these possibilities can contradict major opinions or general heuristics. The product chosen for the development project, a Philips DVD hard-disk recorder, is called a combi because it combines a hard-disk recorder function with a DVD recorder function. Combining the two recorders provided the main added value of having the strong points of one compensate for the weak points of the other.