Two to four candidate architectures, scored across cost, ops burden, lock-in, latency, and compliance — AI scaffolds the matrix and argues each cell, but the weights are set by the architect before scoring begins, because whoever sets the weights decides the outcome.
Tier: Core · Hands-on time: ~30 minutes
The options matrix is the artifact clients and ARBs actually read, and AI collapses its production cost from a day to an hour. The risk is not fabrication so much as laundering: a model that both weights the criteria and scores the options has made the decision for you while appearing to be neutral analysis. This playbook splits the roles — you fix the weights from the engagement's real priorities, the AI drafts candidate scores with reasons, and every score you disagree with becomes a conversation, not a silent overwrite.
Skip AI when there is genuinely one viable option — a matrix with a predetermined winner is theater, and reviewers can smell it.
Set the weights first, alone, in the spreadsheet. Before any prompt: list your criteria and assign weights that sum to 100, from the engagement's actual priorities. For Rajesh's Meridian order-status agent, the client's non-negotiables were data residency and time-to-market, so compliance 30, delivery speed 25, run cost 20, ops burden 15, lock-in 10. Write one sentence justifying each weight — the ARB will ask.
Have AI stress-test the weights — not set them. Paste the weighted criteria: "Argue against my weighting. What would a CFO, a CISO, and the client's ops lead each change, and why? Do not propose a new weighting." Adjust if persuaded; record what changed. The weights are now frozen.
Draft the matrix with argued cells.
Score three candidate architectures for the Meridian order-status agent
against my frozen criteria. Candidates:
A) Managed-agent platform in the client's existing cloud (fully managed
runtime + managed knowledge base)
B) Framework-based build (LangGraph-class) on the client's container
platform, self-managed vector store
C) Extend the client's existing contact-center vendor's AI add-on
Criteria and weights (FROZEN — do not alter or re-rank):
compliance/residency 30, delivery speed 25, run cost 20,
ops burden 15, lock-in 10.
For every cell: score 1–5, then a 2–3 sentence argument citing a
specific property of the option. Mark any argument that depends on a
service limit, price, or regional capability with [VERIFY]. Do not
compute weighted totals — I will do that in the spreadsheet.
Then list, per option: the strongest argument AGAINST it that a
competent rival architect would make.
Move scores to the spreadsheet and re-score by hand. Transfer cells one at a time, adjusting any score you disagree with and noting why in a comment. Cells you change are your judgment on record; cells you keep are your endorsement. Either way, every cell is now yours. The spreadsheet computes the totals — models miscount weighted sums often enough that arithmetic stays deterministic.
Clear the [VERIFY] tags. Every flagged cell gets the pb-05 treatment: vendor doc, today's date, register row. A trade-off matrix that turns on an invented regional limitation is the exact failure this track exists to prevent.
Pressure-test the conclusion. Two closing prompts: "Which single weight change would flip the ranking?" (sensitivity — if a 5-point shift flips it, say so in the brief), and "Steelman the losing options for one paragraph each" (the ARB pre-read writes itself from this). Then write the recommendation in your own words, with the sensitivity note attached.
Candidate architectures reveal client systems and intent. Per the pb-03 register: redact to structural descriptions ("client's existing cloud", "[CONTACT-CENTER-VENDOR]") — matrix logic survives placeholder names intact. For stricter engagements, run drafting on a client-tenancy endpoint (Bedrock/Azure OpenAI in the client's subscription) or local Ollama; the weights step, spreadsheet arithmetic, and verification pass involve no AI and need no variant. Never paste rival-vendor commercial terms received under NDA into any external tool — score those cells from your own reading.
Whoever sets the weights makes the decision. Freeze them before the first prompt, verify every flagged cell, and the matrix stays your analysis — accelerated, not outsourced.