Waterfall Was Never the Problem

Every time I talk about Spec-Driven Development, someone says the same thing. “That is just waterfall.” They mean it as a gotcha. It is not. Two things are going on[...]

Use-Case 3.0: The Refreshed Guide to Driving Development with Use Cases

Use cases have been around since 1987. In May 2024, Ivar Jacobson, Ian Spence, and Keith de Mendonca published a refreshed guide called Use-Case 3.0. If you read my earlier post[...]

AI Writes the Code. This Book Still Teaches the Use Cases.

In the AI Unified Process (AIUP), the spec sits at the center. The use case is the unit of work. You write a system use case, AI generates the code, and tests confirm the[...]

Shift-Left: Getting the Spec Right Before the Code

In software, “shift-left” means doing the important work earlier. The earlier you catch a problem, the cheaper it is to fix. We learned this with testing and later[...]

Bug or Enhancement? How the AI Unified Process Handles Change Requests

In a spec-driven world, every change to the running system has a reason. Either the system does something it should not do, or we want it to do something new. AIUP captures this[...]

What, Harness, How: The Three Layers of AIUP

One of the recurring questions I hear about Spec-Driven Development is this: where does the spec end and the implementation begin? The line is often blurry. Specs leak into class[...]

AI Writes Code. Engineers Build Software.

With Claude Code and similar tools, I do not write much code by hand anymore. The AI does it for me. And most of the time, the result is good. For a moment this looks like the end[...]

Why in Spec-Driven Development the Spec Must Be Readable for All Stakeholders

In Spec-Driven Development (SDD), the specification is at the center. It is not just a document for developers or architects. It is the shared foundation for everyone who works on[...]

How and Why to Trace Use Cases and Tests

When you build business software, the same question keeps coming back: why does this code exist? The honest answer is almost always: because some business person needed it. A[...]

Use-Case 2.0: The Forgotten Practice That Solves What User Stories Can’t

Many teams today treat user stories as the only way to capture requirements. But there is an older, proven technique that scales better and provides something user stories[...]

Why Spec-Driven Development Tools Fail in the Enterprise

The spec-driven development (SDD) movement is gaining momentum. Tools like Amazon Kiro, GitHub Spec Kit, and BMad Method promise to bring structure to AI-assisted coding. And they[...]

A Small App, a Complete Process: Demoing AI Unified Process with a Feedback App

When people hear about AI-assisted software development, they often imagine code generation first. I think that is the wrong place to start.