George Fairbanks:

There are two parts to software development: creating a design and expressing it as code. The code is tangible but the design is conceptual. Keeping a project healthy means doing both well. Here’s my concern: whenever you mix the conceptual with the tangible, it’s easier to neglect the conceptual. When you miss a tangible target, it’s obvious, but when you miss a conceptual target, you might not recognize it, or might rationalize that, because it’s impossible to measure, you were really quite close.

Blindly applying a factory process to software development will drive improvements to the tangible part (the code) at the expense of the conceptual part (the design). We see plenty of examples of this today, where teams have great feature velocity at first, are puzzled when velocity slows, and eventually the project is abandoned. As Cunningham warned, if we bolt features onto an existing codebase without consolidating those ideas into the code, the design will suffer, and over time “[e]ntire engineering organizations can be brought to a standstill under the debt load of an unconsolidated implementation.”