AI Workflow or AI Agent: Choose the Right Architecture

An architecture decision record for a practical business AI workflow, with steps, an acceptance test, and a reusable prompt.

By Dr. Connor Robertson · Published October 24, 2026 · Implementation playbook

Deliverable: An architecture decision record. Use this playbook when your team needs a repeatable operating decision with evidence that another person can inspect.

The business situation

A customer onboarding process with intake, validation, account creation, and welcome email. This is an illustrative scenario, not a reported client result. Start with a small approved sample and the actual constraints of your team.

The operating approach

List the steps whose sequence is known. Use a fixed workflow for those steps. Give an agent only the ambiguous part, such as identifying missing intake details; return its result to a validated workflow.

Build it step by step

  1. Draw the current process with its inputs and exit conditions.
  2. Mark which branches require interpretation and which follow a rule.
  3. Build the simplest version with one model call for the ambiguous step.
  4. Compare completion, corrections, latency, and cost with a deterministic alternative.

A concrete acceptance test

Use a form missing its billing contact. The system should request the missing information and stop before account creation. A complete form should follow the fixed path without extra reasoning loops.

Record the input, expected behavior, actual result, reviewer, and version tested. Repeat this case after a prompt, source, model, or integration change. Include the cases that failed in the next regression run.

The mistake to avoid

Choosing an agent because it sounds more advanced creates more decisions to test. If a rules-based branch handles the input reliably, retain it.

A reusable working prompt

Write an architecture decision record for this process. Separate deterministic steps from interpretation. Specify inputs, output schema, stop conditions, permissions, and a simpler alternative. Do not assume integrations exist.

Replace general descriptions with your approved process details. The prompt helps prepare an artifact; the process owner verifies the finished result before it changes a live workflow.

What to keep in the handoff

Save the accepted an architecture decision record, its source versions, test evidence, unresolved questions, and a named owner. Set a review trigger tied to a meaningful business change, rather than leaving the pilot without maintenance.

Continue implementation

Explore AI Agents and Integrations or contact Dr. Connor Robertson about your business workflow.