Final CCAR-P revision covering discovery, communication and architectural decision-making.
Discovery
Capture before designing:
Business goals
Success criteria
In-scope users
Latency constraints
Cost constraints
Audit requirements
Data sensitivity
Regulatory requirements
Vague Requirements
If a stakeholder says:
“Build AI to fix customer escalations.”
Ask:
Who is involved?
What triggers escalation?
What does good resolution look like?
What are the latency/cost/audit/data constraints?
Do not jump straight to model selection or architecture.
Functional vs Non-Functional Requirements
| Functional | Non-Functional |
|---|---|
| Classify tickets | p95 latency |
| Extract invoice fields | Cost ceiling |
| Generate a draft | Throughput |
| Route a request | Audit requirement |
Architecture Decision Record — ADR
Include:
Context → Decision → Alternatives → Trade-offs/Consequences → Owner/Date
Also define a review cadence when assumptions may change.
Implementation Guide
Include:
Component responsibilities
Interface contracts
Sequence diagrams / dominant flows
Configuration parameters
Operational runbooks
Operational Runbook
Include:
Alert → Triage → Escalation → Rollback → Dashboard/Logs
Communication by Audience
| Audience | Primary Focus |
|---|---|
| Executive | Business outcomes, trade-offs, high-level risks. |
| Engineering | Components, interfaces and implementation details. |
| Security / Compliance | Threat model, controls, residual risk and auditability. |
| Product | Capabilities, scope and roadmap dependencies. |
Business Value
| Pillar | Meaning |
|---|---|
| Efficiency | Same work faster or more work per person. |
| Productivity | Actual business output improves. |
| Transformation | Operating model or role fundamentally changes. |
| Solution Cost | API/infrastructure spending. |
| Performance SLA | Latency/reliability against agreed targets. |
Stakeholder Management
If scope increases during delivery:
Acknowledge it → explain timeline impact → offer options.
Typical options:
Defer the new scope.
Remove other scope.
Extend the timeline.
Iteration
After production:
Telemetry + Evaluations + Stakeholder Feedback → Highest-Impact Improvement
Do not throw away the existing evaluation framework after go-live.
CCAR-P Last-Minute Cheat Sheet
Fixed predictable steps → Workflow
Dynamic planning → Agent
Authoritative knowledge + citations → RAG
Reusable procedure → Skill
Live external system → MCP
Recurring specialist task → Subagent
Many MCP tools → Tool Search
Shared team config → Project scope
Non-overridable policy → Managed config
Personal setting → User scope
High-impact irreversible action → Human gate first
Repeated static prompt → Prompt caching
Simple high-volume task → Smaller/faster model
Restricted data → Authorise before retrieval
Credential → Secret store
Model output → Validate before downstream action
Model upgrade → Re-run stable evaluation set
Vague requirement → Discovery first
Accuracy must remain unchanged → Remove redundant cost first
Final Exam Mindset
When two answers look correct, prefer the option that is:
More measurable
More least-privilege
More risk-based
More evidence-driven
More auditable
More reversible
More clearly aligned to stated requirements
