It seems incredible that the room picked for this talk was so small. As could be expected it was filled and overfilled.

I always seem to walk out of Kent Beck’s talks with mild disappointment. This is probably an effect of me expecting a full hour of breath taking and ground breaking material from him. The reality is that the material he presents is so refined (reduced to its simplest form but no simpler) that most of the talk is filling.

Building on previous work, he started with a definition of design and the influence of values (how do I evaluate the quality of a design) and principles (to some extend an operational effect of the values) on the design as well as the use of patterns.

Then came the core of the talk: design strategies. Kent Beck identified four design strategies from his experience. They are really strategies to evolve a design.

• First is the leap, jumping from one design to another in a single go.
• Second is Parallel, where the old design and the new one will co-exist for a while.
• Third is the stepping stone, whereby successive intermediary steps are defined and implemented before arriving to the new design.
• Fourth is simplification, whereby the design is made for a simplified version of the problem and then enriched by reintroducing the complexity.

I will craft examples around boat building to better explain what I understood. Leap would be to transform a sail boat into a motor boat by cutting the mast and adding a motor. Parallel would be adding a motor and when that motor works in a satisfying manner removing the mast. Stepping stone would be, starting from scratch to build a hull that floats, then add flooring and oars and verify the boat navigates, finally add a motor. The simplification would be to build boat that can navigate on a lake on a calm day, then enhance it to navigate on a stormy day, then adapt it to navigate close to the coast and finally adapt it to navigate on the open ocean.

I wonder if prototyping is also a distinct design strategy.

Anyway, overall a valuable talk from Kent Beck. Much better than last year’s or this year’s keynotes.

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