Build-an-X workflow that takes an SDET from no test suite to a complete framework design in seven steps - inventory the SUT, choose runner + language, directory layout + fixture architecture, object-model decision, test data + mocking wiring, reporting + CI integration, conventions doc + review gates - producing a written framework blueprint (directory tree, fixture list, chosen patterns, CI matrix) plus an implementation order. This is the whole-framework design workflow - not the Step 2 runner-choice decision on its own, not the Step 4 object-model pattern catalog it defers to, and not the scaffolder that generates the harness skeleton once the blueprint exists. Use when designing a test automation framework from scratch or re-architecting one that grew organically.