Development 2024-04-12 · 9 min

Requirement-First Development

How writing down what the system must do — before what it looks like — prevents scope creep, rework, and the "I thought you meant..." conversation.

SYSTEM BLUEPRINT // REQUIREMENTS-FIRST FIG. 01
SPEC_ID SOURCE & BOTTLENECK REQUIREMENT STATEMENT ACCEPTANCE CRITERIA REQ-001 Ops / Multi-Warehouse Manual stock syncing Atomic inventory ledger updates on order confirmation < 200ms latency Zero negative balance REQ-002 Finance / Accounts 3-day invoice delay Auto-generate PDF invoice & dispatch via WhatsApp 100% automated delivery Audit record created REQ-003 Executive / Leadership Disconnected data Real-time daily EBITDA & cash collection telemetry Live sub-second refresh Role-based encrypted access SPEC IS SIGNED OFF BEFORE WRITING CODE — ZERO AMBIGUITY, ZERO SURPRISES.

Every feature traces back to a documented workflow, a measured problem, a person you can name. If a requirement cannot be written, it cannot be built — and we say so early, in writing.

The cost of implicit requirements

Implicit requirements are the source of almost every project overrun. "I thought the dashboard would filter by date." "I assumed the export would include archived records." "The client said they wanted it simple, so I did not build the admin panel."

Our requirement format

Every requirement in our specifications follows a structure:

  • ID — unique, traceable.
  • Source — who asked, what workflow, what pain.
  • Statement — what the system must do, in one sentence.
  • Acceptance criteria — how we know it is done, testable.
  • Priority — must, should, could, wont.

The spec is a living document

Requirements change. That is not failure — it is learning. But every change is an explicit edit to the spec, with a reason, an impact assessment, and a client sign-off. Nothing moves by memory.

What this buys you

  • No surprise features at demo day.
  • A shared definition of done.
  • A spec a new engineer can read and build from.
  • A project that can be paused and resumed without knowledge loss.