Build vs. Buy vs. Inference Advisory Engine
Your SaaS vendor charges per seat, per month, forever. Model the 3-year total cost of keeping that subscription vs. building organization-owned code — across 7 verticals.
Commercial & Workflow Parameters
Interactive ModelHybrid Architecture: Organization-Owned Core + Targeted AI Routing
Deploy organization-owned deterministic rules for 65% of structured transactions, reserving targeted model-assisted inference for the remaining 35% unstructured ambiguity.
Strategic Decision Rationale
- Permanent source-code ownership eliminates compounding 5% annual SaaS renewal price hikes.
- Derives 65% of operations from deterministic code, minimizing non-deterministic hallucinations.
- Fractional stewardship/maintenance of 15% ($7,050/yr) + $1,800/yr hosting ensures active oversight.
Key Risks & Model Assumptions
- Internal code maintenance required: models 15% ongoing fractional stewardship, never $0 ongoing operational cost.
- Edge model hosting must be monitored for token rate limit throttling during peak volume surges.
Enterprise Catalog Disqualification & Turnkey Context Core
Heavyweight enterprise catalogs are disqualified for mid-market and SMB organizations due to prohibitive seat floors and full-time platform engineering overhead.
Deploy lightweight organization-owned semantic layer alongside the client's existing workspace UI with zero per-seat tax.
5-Domain Functional Platform Connection Matrix
Pre-configured integration patterns, auth controls, semantic gotcha protections, and Stage 0–2 SOW pricing.
Webhook + Nightly Parquet Sync + MCP execute_metric_query
Auth & Security ControlScoped OAuth2 / token rotation schedule (e.g., QBO 101-day token refresh alert & HubSpot private app token rotation)
Deal-to-Ledger grain divergence: Prevents CRM sales pipeline booking date and deal amounts from corrupting GAAP revenue recognition schedules.
FastMCP Metric Tool Callexecute_metric_query(metric_id='active_customer_count', dimensions=['tier'], as_of_date='2026-10-31')Annual Cash Outlay (Y1–Y3) & 3-Year Discounted NPV (@ 8%)
Year 1–3 series are undiscounted annual cash outlay; the 3-Year NPV series is discounted
Detailed Architecture Cost Matrix
| Architecture | Year 1 | Year 2 | Year 3 | 3-Yr NPV | Δ NPV vs. SaaS | Suitability |
|---|---|---|---|---|---|---|
| Commercial SaaS Subscription | $43,500 | $29,925 | $31,421 | $95,532 | $0 | Eligible |
| Organization-Owned Software (Custom Rules) | $55,850 | $8,850 | $8,850 | $71,200 | +$24,332 | Screened out (>25% unstructured) |
| Pure AI / LLM Pipeline | $52,000 | $52,000 | $52,000 | $133,950 | -$38,418 | Eligible |
| Hybrid Architecture (Deterministic Core + Inference) | $59,350 | $12,350 | $12,350 | $80,560 | +$14,972 | Eligible |
Workload routing split: 65% Deterministic Rules / 35% Model Inference (derived from the 35% unstructured input). Recommendation = lowest 3-year NPV among architectures eligible for this workload.
