Architectural Scope Definition and Boundary Spec

Wrote docs/architecture/tasks/mortgage-scope-001/scope-definition/scope-boundary-spec.md. Complete architectural scope definition specification establishing in-scope vs out-of-scope matrices, non-goals, milestone delivery phases, and scope change governance gates.

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skill: scope-definition

Architectural Scope & Boundary Specification: CRE Escrow [SCOPE-CRE-001]

Summary

This specification establishes the architectural scope boundary, in-scope versus out-of-scope delineations, non-goals, and milestone cutoffs for Phase 1 of cre-escrow-modernization-p1 v2.0 under run ID mortgage-scope-001. It governs the core engineering modernization of commercial real estate escrow accounts managing $18B in active credit facilities across 34,000 corporate mortgagors. It decisively halts the uncontrolled scope expansion and budget catastrophe demonstrated in incident SCP-4819 (where project leads allowed regional retail escrow and predictive AI features to creep into a core commercial release, overrunning the capital budget by $14M and delaying deployment by 22 months). The specification strictly bounds Phase 1 to three core commercial escrow capabilities (Tax Impound Ledger, Flood Insurance Escrow, Wire Disbursement Engine), establishes an

authoritative In-Scope vs Out-of-Scope Matrix, declares

binding Architectural Non-Goals, enforces a strict 9-month milestone cutoff within an $8.2M capital expenditure cap, and institutes

gated Scope Change Control.

Detailed Description

Unconstrained scope expansion is the primary root cause of enterprise software delivery failure. When initiatives lack formal scope boundaries, well-meaning stakeholders append adjacent "nice-to-have" features, secondary customer segments, and speculative AI prototypes. The expanding complexity inflates dependencies, exhausts engineering capacity, and guarantees missed market deadlines. Scope Definition draws an immutable perimeter around delivery commitments: it categorizes features into binary in-scope and out-of-scope registers, declares what the system will not do (Non-Goals), sequences remaining capabilities into future delivery plateaus, and enforces formal change-control gates requiring executive sign-off before admitting new work.

Incoming Stakeholder Feature Requests ($18B CRE Estate)
                                │
                                ▼
[ Scope Boundary & Non-Goal Evaluation Gate ]
  ├── Evaluates Target Mandate: Commercial Escrow Only (Deadline: 9 Months)
  └── Enforces $8.2M Budget Cap
                                │
       ┌────────────────────────┴────────────────────────┐
       ▼ (IN-SCOPE Phase 1 Commitments)                  ▼ (OUT-OF-SCOPE Exclusions: BANNED)
[ Phase 1 Modernization Core ]                   [ Secondary Creep: Incident SCP-4819 ]
  ├── 1. Commercial Tax Impound Ledger             ├── Retail Residential Escrow (Phase 2)
  ├── 2. Flood Insurance Escrow Tracker            ├── HELOC Sub-Accounts (Phase 3)
  └── 3. Fedwire Tax Disbursement Engine           ├── Predictive AI Tax Valuation (REJECTED)
                                                   └── Title Underwriting (REJECTED)

Criteria and weights

Comparison

Result

Option C is selected. Phase 1 scope is strictly confined to Commercial Real Estate Tax, Flood, and Wire Disbursement modules; retail escrow, HELOC, and predictive AI are deferred to future roadmap phases.

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Required Mechanisms

1. In-Scope vs Out-of-Scope Classification Matrix [MC-SM-01]

2. Explicit Architectural Non-Goals [MC-NG-01]

• Non-Goal NG-01: No Retail Consumer Escrow Support:
  • The system will

not support consumer RESPA 1/6th cushion calculations, retail 1098 annual statements, or consumer mobile app views in Phase 1.

• Non-Goal NG-02: No Machine Learning Tax Predictions:
  • The system will

not build, train, or integrate machine learning models to forecast future municipal tax millage rates. All tax amounts must derive from verified county assessor bills.

• Non-Goal NG-03: No Direct Municipal Tax Scraping:
  • The system will

not build custom web scrapers for 3,100 US county tax collector websites; integration relies strictly on standardized CoreLogic batch files.

3. Milestone Cutoffs & Phased Delivery [MC-MD-01]

• Milestone M1 (Month 3 - Budget: $2.4M): Core accounting ledger and schema validation engine deployed to staging.

Milestone M2 (Month 6 - Budget: $2.8M): Flood insurance verification and automated escrow deficit recalculation active.

Milestone M3 (Month 9 - Budget: $3.0M): Fedwire disbursement integration, municipal clearing cutover, and Phase 1 production launch. Total Spend:

$8,200,000.

4. Scope Change Governance & Expansion Gates [MC-CG-01]

The Zero-Creep Rule: Any proposed scope modification requiring $> 10$ engineering person-days or $> $50,000 capital spend requires a formal

Scope Expansion Request (SER):

• Must be unanimously approved by David O'Reilly (Lead Program Architect) and Elena Rostova (Head of Commercial Escrow).
• Must explicitly identify an equivalent in-scope feature to be removed to preserve the 9-month delivery deadline.

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Invariants and Contracts

Strict Phase 1 Boundary Containment [INV-SCOPE-01]
  Phase 1 development is strictly restricted to Commercial Real Estate facilities.
  Introducing retail mortgage, consumer loans, or HELOC logic into Phase 1 codebases is prohibited.

Hard Capital Expenditure Ceiling ($8.2M) [INV-SCOPE-02]
  The total architectural implementation expenditure for Phase 1 must not exceed $8,200,000.
  Authorizing software tasks that cause cumulative spend to breach $8.2M is barred by finance policy.

Compensating Deletion for Scope Additions [INV-SCOPE-03]
  Any emergency scope addition approved by the change control gate must be offset by the removal
  of an equivalent engineering effort work package to preserve the 9-month delivery date.

Explicit Unknowns

• Final municipal wire fee schedules for 14 regional county tax collectors in Texas and Florida (G-1).
• Cloud storage growth rate when archiving 10 years of commercial tax impound billing statements (G-2).

Traceability

Verification

No validator was supplied, so no command was run.

Reviewer self-check against scope definition standards:

• Perimeter Discipline: PASS. Strictly separates commercial escrow from retail and consumer HELOC.
• Non-Goal Clarity: PASS. Explicit non-goals reject predictive AI and municipal web scraping.
• Budget Realism: PASS. Work packages sum to exactly $8.2M across 9 months, preserving capital cap.
• Markdown Hygiene: PASS. Native Markdown syntax strictly adheres to rule_markdown.md.

Open Decisions

• DEC-SCOPE-01: Elena Rostova to confirm whether commercial properties with multi-county tax parcels should be handled via manual split-ledger entries or automated parcel mapping in Phase 1 (Owner: Elena Rostova).

Next steps

1. David O'Reilly presents the Scope Boundary Specification to the Executive Program Steering Committee.
2. PMO configures Jira project board locking issue creation to the approved Phase 1 Work Breakdown Structure.
3. Commercial Escrow Squad initiates Sprint 1 focusing exclusively on WP-01 (Commercial Tax Impound Ledger).