Following my earlier discussions of testing and defect fixing, I’ll complete the trilogy by discussing the role of design early in projects. Recall the context: projects that have validated a genuine need by haven’t validated an economic proposition. Because of the uncertainties of such a situation, iteration is inevitable. Piloting a project on the runway you will like have to try many experiments to find value customers will buy. Capital efficiency while iterating extends the lifespan of the project and increases its chances of success. The more experiments you can perform per dollar, the higher your expected return.
In the sibling essays to this one I argued that the Extreme Programming principles of Test Until Bored and Defects Zero were perfectly appropriate to the cruise phase of a product, where the business driver is increasing profit by lowering cost. These principles also serve to prepare the software to act as a platform from which to