07-assumptions.md
Each assumption is recorded with rationale, basis, and impact-if-wrong. Phase 7 consolidates and reviews this ledger; phases prior write/update entries as they are made.
| ID | Phase | Assumption | Basis / rationale | Impact if wrong |
|---|---|---|---|---|
| A-001 | 2 | Project is greenfield (new construction), not rehabilitation | Construction Bulletin No.8 dated Nov-2025; "For Construction" status; design revisions for new kitchen layout; no existing-system inventory in inputs. Cover-letter wording disagrees → Q-015. | If actually rehab: add demolition takeoff, after-hours premiums, hot-cutover plan, existing-cable reuse evaluation. Cost impact ±25–30%. |
| A-002 | 2 | Tier = Medium (PHP 25M–50M); ~600–700 BMS hardwired points + ~67 HLI | Project-specific BMS Points list summary; typical hospitality density. | If actually large: add senior PM, double-shift T&C, additional supervisory engineer. ±15% on manhours. |
| A-003 | 3 | Building floor count: B1, LG, GF, 2F, 3F, 4F–9F (typical guestroom), Roof Deck — ~10–11 stories | ECE auxiliary plans per floor (page 11–22) + BMS Points list level references. Subject to Q-001/Q-004. | Cable risers ±1 floor per assumption error (~30–50 m per riser). |
| A-004 | 3 | BMS scope excludes per-room guestroom HVAC controls (FCU thermostats, occupancy sensors, PMS-driven setbacks) | Project-specific BMS Points list shows no guestroom FCU points. | If included: add ~2,000–4,000 points + per-room FCU controllers + thermostats + PMS gateway → +PHP 8M–15M. → Q-001. |
| A-005 | 3 | Mechanical layouts per typical hotel density: 1 plant room (B1/2F), AHU/DOAS in mechanical rooms per floor zone, exhaust fans on roof, calorifiers at LG and Roof Deck (per BMS Points list zoning) | BMS Points list zone tags (LG, 2F, RD); ECE plans show plant-room outlines. | Equipment placement ±15 m typical floor, affects cable lengths only. → Q-002. |
| A-006 | 3 | BMS LAN: isolated Layer-2 BMS network, single managed uplink to customer LAN; BACnet/IP at head-end and supervisory level, BACnet MS/TP at field controllers | Megaworld MC Standards (DRC-004-2024) cited convention; internal preferred topology. | If full IP-to-field: add per-controller IP licensing + larger switch count. ±PHP 1–2M. → Q-007. |
| A-007 | 3 | Brand preference: Siemens for BMS controllers / DDC / supervisory / PLC / FDAS / SCADA; Dell for head-end PCs/servers; managed switches Cisco/Aruba; UPS APC/Eaton; BTU/power meters Belimo + 7KM (Siemens SENTRON family) | Megaworld customer-kb is STUB; internal preferred per _playbook/checklists/preferred-brands.md. | If customer brand-locks otherwise: re-quote at customer-approved brand prices (typical ±5–15%). → Q-008. |
| A-008 | 3 | PMS (hotel property management system) integration is not in BMS base scope; provided as priced optional add-on | Cover letter is silent; per Megaworld bms-hospitality-casino checklist default. | If required: add ~PHP 800K (gateway + custom mapping). → Q-009. |
| A-009 | 3 | Casino-zone special points (vault, count-room, smoking exhaust) covered at default minimums per bms-hospitality-casino checklist; not separately enumerated in customer points list | BMS Points list shows DOAS-Casino + smoke-sanitizer; vault/count-room not addressed. | If required: add ~30–60 additional points + door-status hardware. ±PHP 300–500K. → Q-010. |
| A-010 | 3 | BOH kitchen exhaust monitor-only (run-status only); no Ansul/hood-fire-suppression integration | BMS-01 ventilation block lists kitchen TEFs as run-status. | If required: add interlock relays + integration spec. ±PHP 200K. → Q-011. |
| A-011 | 3 | Project schedule: 14-week construction + T&C window (assumed comfortable for medium-tier scope) | No customer schedule; medium-tier reference timeline. | Compressed to <10 weeks: double-shift, after-hours premiums (+20% manhours). → Q-003. |
| A-012 | 3 | Commercial terms: PHP currency; warranty 12 months from substantial completion; payment 90% progressive / 10% retention released at warranty completion; no LD beyond 0.1%/day capped at 5%; tax inclusive (12% VAT) | Standard Philippine market default; customer is silent. | Customer-imposed harsher terms shift contingency 1–3% of contract value. → Q-012. |
| A-013 | 3 | Working hours: standard daytime construction (Mon–Sat 0700–1700); no after-hours or noise-restricted work expected | Greenfield site assumption. | Hotel-tower fit-out windows imposed (night/weekend): +15–25% labor premium. → Q-013. |
| A-014 | 3 | Training: one round (8 hours, on-site) of operator training included; no extended O&M contract | Cover letter silent on training/O&M. | Extended O&M (1–3 yr): add separate priced line item. → Q-014. |
| A-015 | 3 | Power riser EE-24 Part 2 of 2 covers guestroom-tower distribution; metering scope confined to MV main + major mechanical/casino feeders + per-floor BOH lighting feeders (not per-guestroom-feeder metering) | Riser Part 1 visible; Part 2 not in bundle. | Per-guestroom-floor metering required: add ~10 power meters + ~2,000 m additional cable. ±PHP 600K. → Q-005. |
| A-016 | 3 | Network architecture: 1× supervisory server, 1× operator workstation, 1× HMI workstation, 1× engineering laptop; isolated BMS LAN with managed L2 switches | Standard hotel BMS reference; A6 will refine. | Casino regulatory requirements may require redundant supervisor: ±PHP 800K. → Q-007. |
| A-017 | 3 | Cable jacket: FRLS (fire-retardant low-smoke) per Megaworld MC Standards + BFP IRR | Customer-kb note + standard practice. | Higher rating (FR-LSZH or FT-FT4): +10–20% cable cost. |
| A-018 | 3 | Conduit/cable-tray supply: BMS contractor responsible for vertical conduit runs and BMS panel-room internal trunking; horizontal cable tray (main building) provided by ME contractor | Standard scope-split per Philippine market. | If BMS contractor must supply main tray: +PHP 1.5–3M. |
| A-019 | 3 | Reasoned typical-range cable lengths populated in A3-route-lengths.yaml (Phase 5a) per context: plant-room same-room ~12 m, inter-floor riser ~3.5 m per floor + 8 m per panel allowance, guestroom-corridor field cable ~35 m, casino-floor field cable ~28 m | Per Operating Principle #11; basis: Philippine hotel-BMS prior projects + cable industry typical-route guidance. | Variance ±20% per context affects A3 cable totals proportionally. |
| A-020 | 3 | Conduit-to-cable ratio: 30% (used by generate-b4-installation-manhours.py) | Helper default; flagged as known issue in ORCHESTRATOR.md. | If retrofit (50–70%) or if dedicated vertical conduit is heavy: +/−15% on conduit cost. |
| A-021 | 3 | Spare I/O capacity: 25% per AI/AO/DI/DO module sizing | generate-06-boq.py default. | More aggressive (10%): smaller controller count; less aggressive (40%): more. ±5% on hardware cost. |
| A-022 | 3 | Trend logs: 100% of AI, 40% of DI, 70% of HLI logged | generate-b1-b3-programming-and-commissioning.py default. | Casino regulatory trending requirements may push higher. |
| A-023 | 3 | Cable lengths: trunk panel-to-panel measured from EE-03/06/09/12; vertical risers measured from EE-24 (Part 1); plant-room same-room cables measured from zone tags; guestroom-corridor and casino-floor field cables fall back to reasoned typical ranges per A-019 | Drawing-availability triage in Phase 3. | Per Phase-3 triage, the customer-facing language must disclose what was measured vs. what fell back. |
| A-024 | 3 | Equipment counts: BOH/casino/roofdeck equipment quantities directly from BMS Points list (TUEC); guestroom-corridor FCU counts (if confirmed in scope per Q-001) at typical density of 1 FCU per guestroom + 2 FCU per typical floor corridor | BMS Points list + typical hotel density. | ±15% if guestroom layout differs materially. |
| A-025 | 3 | Casino MVAC point count: per BMS-02 visible (DOAS ×2 + smoke sanitizers ×2 + AHU ×2 + cooling tower interface) | BMS Points list (TUEC) BMS-02. | If gaming-board adds further requirements: +30 points. → Q-010. |