Lean Architecture for Agile Software Development

Chapter 5. What the System Is, Part 1: Lean Architecture

Starting anew with a clean slate has been one of the most harmful ideas in history.

—The Clock of the Long Now, p. 74..

Grandpa Harry had a riding lawnmower that he owned for about a decade. He took very good care of the machine, keeping it well oiled and in good repair. He knew every inch of that machine: each bearing, each belt, each linkage, and each engine part.

However, the lawnmower broke down after many years of loving use. The manufacturer had long ceased to stock parts for the old machine. We went down to the local repair shop where a couple of Grandpa Harry's contemporaries had been repairing small motors for years. Bill greeted us as we worked our way to his desk in the middle of the shop. The place was a mess: lawnmower carcasses, disembodied parts and fragments scattered everywhere. A casual visitor could see neither rhyme nor reason to the arrangement of parts in that shop; indeed, other than in Bill's memory, there probably was none.

But, yes, they had the part, and Bill worked his way gradually toward the treasure, moving obstacles large and small along the way. He came back to Grandpa Harry, part in hand, and sent us on our merry way after we paid a token fee for the almost-antique piece of gadgetry. Bill must have had a map of that entire mess in his head. Perhaps his frequent rummaging kept the map current, but only he and his partner knew the whereabouts of things.

It's a complex task to find our way around ...