How is the overall TIA-942 compliance score calculated?

Each domain computes a weighted raw score: sum of met-item weights divided by total domain item weights, expressed as a percentage. The overall score is the sum of (domain_pct × domain_importance_factor) divided by the sum of (100 × domain_importance_factor) across all six domains.

What are the six TIA-942 compliance domains?

Site & Architecture (weight 1.0×), Electrical (1.5×), Mechanical/Cooling (1.3×), Telecommunications (1.0×), Fire Protection (1.1×), and Physical Security (0.9×). Electrical and Mechanical carry the highest importance factors reflecting their criticality to continuous IT operations.

How does facility-type filtering work?

Each checklist item carries a dcTypes array. When the user selects a facility type (Enterprise, Colo, Hyperscale, Edge, or Modular) the engine filters ITEMS to only those whose dcTypes array contains the selected type AND whose tiers array contains the selected tier. The resulting applicable set varies from roughly 40 (Edge Tier 1) to 80+ (Hyperscale Tier 4) items.

TIA-942 Compliance Checklist — Methodology & Scoring

01 Purpose & engineering basis

The checklist is a prescriptive, weighted self-assessment tool for rating a data center against ANSI/TIA-942-B — the Telecommunications Infrastructure Standard for Data Centers published by the Telecommunications Industry Association. It answers three questions: what is the facility's current compliance score against a chosen tier, which specific items are unmet (the gap list), and what is the remediation priority order.

The governing standard is ANSI/TIA-942-B (2017) with supplemental references from the Uptime Institute Tier Classification System and BICSI 002-2019. Tier definitions (Basic · Redundant Components · Concurrently Maintainable · Fault Tolerant) follow the TIA-942-B four-tier ladder. Each tier is additive: a Tier 3 facility must satisfy all Tier 1 and Tier 2 requirements plus its own.

Prescriptive checklist, not a certified audit. The tool produces an indicative compliance score for pre-design, gap analysis, and engineering education. A formal TIA-942 certification requires an on-site audit by an accredited third party. See §8 (Assumptions & Limitations) for full scope disclaimer.

02 Inputs

Three filter inputs scope the applicable item set; one per-item binary input drives scoring. No numeric quantities are entered — this is a yes/no compliance gate, not a sizing calculator.

Input	Values	Effect
Tier level `currentTier`	1, 2, 3, 4 (default 3)	Filters items whose `tiers[]` array contains the selected tier. Items are cumulative — Tier 3 shows all items marked for tiers 1, 2, and 3.
Facility type `currentDcType`	`ent` / `colo` / `hyper` / `edge` / `mod` (default `ent`)	Filters items whose `dcTypes[]` array contains the selected type. Certain items are facility-type-exclusive (e.g. liquid-cooling infrastructure only for `hyper`; ruggedised enclosure only for `edge`).
Per-item met/not-met `checkedItems[id]`	true / false (default false)	Boolean flag for each applicable item. The scoring engine sums weights for all `true` items against the domain total.
Evidence (N/A path)	Implicit — item excluded by filter	Items outside the tier or facility-type filter are not shown and do not count toward any score. There is no explicit N/A toggle; the filter pair acts as the N/A gate.

Item counts by facility type at Tier 3 (the default): Enterprise 46 items · Colo 53 items · Hyperscale 58 items · Edge 39 items · Modular 44 items. Tier 4 adds items with tiers:[4] or tiers:[3,4].

03 Calculation methodology

The scoring engine runs in calculate(). It computes a per-domain weighted score, then folds the six domains into an overall compliance percentage using importance multipliers. A Composite Risk Index (CRI) applies an imbalance penalty when domain scores are highly uneven.

Step 1 — Per-domain item-weight score

domain_pct(d) = ( Σ w(i) for all met items i in domain d ) / ( Σ w(i) for all applicable items i in domain d ) × 100 In calculate(): checkedW / totalW * 100 per domain. Each item carries weight w ∈ {1, 2, 3} (Standard / Important / Critical). Met = checkedItems[it.id] === true.inline JS · calculate()

Step 2 — Domain importance factors

totalWeightedScore = Σ ( domain_pct(d) × importance(d) ) over all 6 domains totalMaxWeight = Σ ( 100 × importance(d) ) over all 6 domains Domain importance factors (from CATEGORIES[].weight): Site & Architecture 1.0 · Electrical 1.5 · Mechanical/Cooling 1.3 · Telecommunications 1.0 · Fire Protection 1.1 · Physical Security 0.9. Total max weight = 6.8 × 100 = 680 points.CATEGORIES · data model

Step 3 — Overall compliance percentage

overall = totalWeightedScore / totalMaxWeight × 100 [%] This is the primary displayed score (the large percentage in the results panel). Grade thresholds: A+ ≥95%, A ≥85%, B ≥75%, C ≥65%, D ≥50%, F <50%.inline JS · calculate()

Step 4 — Composite Risk Index (CRI) with imbalance penalty

avgPct = mean( domain_pct[0..5] ) variance = Σ ( domain_pct(d) − avgPct )² / 6 imbalancePenalty = min( 0.15 , √variance / 200 ) CRI = max( 0 , overall × ( 1 − imbalancePenalty ) ) The CRI penalises facilities that score high in some domains but very low in others. Maximum penalty is 15%. A perfectly balanced facility (all domains equal) has zero penalty. A facility with σ = 40 pp carries a 20%/200 = 10% penalty.inline JS · calculate()

Step 5 — Maturity level

maturity = CRI ≥ 95 → L5 Optimized CRI ≥ 80 → L4 Managed CRI ≥ 60 → L3 Defined CRI ≥ 40 → L2 Developing CRI < 40 → L1 Initial 5-level maturity model derived from CRI (not raw overall %). A high-scoring but imbalanced facility may be L3 rather than L4 due to the imbalance penalty.inline JS · calculate()

Gap count and remediation path

gaps = { item : all applicable items where checkedItems[item.id] is false } gaps sorted by w descending (W3 first, then W2, then W1) gap_count = |gaps| (total unmet applicable items) compliance_path_timeline = gap_count / closure_rate (user-defined, not computed) The checklist computes gap count and sorted priority; it does not compute closure-rate or timeline (those are site-specific). Estimated remediation cost bands from the roadmap: W3 (Critical) $50K–200K / 3–6 months · W2 (Important) $10K–50K / 1–3 months · W1 (Standard) <$10K / <1 month.inline JS · updateProPanels()

Sensitivity impact per unmet item

impact(item) = overall_if_item_checked − overall_current Computed by simulating the score with item temporarily set to met, then subtracting the current score. Ranks unmet items by marginal overall-score improvement. Top 10 items form the Sensitivity panel.inline JS · updateProPanels() / sensItems

04 Constants & data sources

All structural constants live in the inline CATEGORIES, DC_TYPES, and ITEMS arrays. No external data files are loaded.

Domain	ID	Importance Factor	Item weights	Rationale
Site & Architecture	`site`	1.0×	W1–W3	Structural/location foundation — critical but lower operational frequency than power/cooling.
Electrical	`elec`	1.5×	W1–W3	Highest impact: power failure is the primary cause of data center downtime.
Mechanical / Cooling	`mech`	1.3×	W1–W3	Thermal events are the second largest failure cause; long recovery times.
Telecommunications	`tel`	1.0×	W1–W3	Cabling and connectivity infrastructure — critical but more easily remediated.
Fire Protection	`fire`	1.1×	W1–W3	Life-safety and catastrophic-loss risk; slightly elevated above site/telecom.
Physical Security	`sec`	0.9×	W1–W3	Important but failures are lower-frequency and more reversible than infrastructure failures.

Item Weight	Label	CSS class	Meaning
`w: 3`	Critical	`.w3`	Non-negotiable for the tier. Failure to meet = high-impact gap (P1). Examples: UPS 2N for Tier 4, dual utility feeds, VESDA detection.
`w: 2`	Important	`.w2`	Significant operational risk if absent. P2 gap. Examples: N+1 cooling redundancy, clean agent suppression, hot/cold aisle containment.
`w: 1`	Standard	`.w1`	Good practice; lower risk if deferred. P3 gap. Examples: TIA-606 labeling, Cat 6A copper, branch circuit monitoring.

Facility Type	ID	Typical item count (Tier 3)	Key exclusive items
Enterprise	`ent`	~46	Standard full set including raised floor, humidity control.
Colocation	`colo`	~53	Per-tenant revenue-grade metering, cross-connect room, SLA monitoring, multi-tenant cage isolation.
Hyperscale / Cloud	`hyper`	~58	Direct-to-chip liquid cooling, immersion cooling, medium-voltage row distribution, overhead busway, solid floor with overhead cable management.
Edge / Micro	`edge`	~39	IP55+ ruggedised enclosure, cellular/satellite backup connectivity, remote monitoring, compact self-contained cooling, BESS, aerosol suppression.
Modular / Prefab	`mod`	~44	Modular anchoring, pre-terminated trunk cables, factory-integrated suppression, hot-swappable components, BESS, remote monitoring.

The base ITEMS array contains 56 canonical items plus facility-type-specific extension items (liquid cooling, BESS, remote management, etc.) for a total of 79 items in the array. At any given tier/facility-type combination, the visible applicable set is always a subset of these 79.

05 Outputs

Output	Formula / source	Unit	Interpretation
Overall compliance score	`totalWeightedScore / totalMaxWeight × 100`	%	Primary headline metric. Weighted across all 6 domains by importance factor.
Grade	Threshold lookup on overall%	A+/A/B/C/D/F	A+ ≥95% · A ≥85% · B ≥75% · C ≥65% · D ≥50% · F <50%.
Composite Risk Index (CRI)	`overall × (1 − imbalancePenalty)`	integer 0–100	Penalised score; equal to overall when all domains score identically. Drives the maturity level.
Maturity level	CRI threshold ladder	L1–L5	Initial / Developing / Defined / Managed / Optimized.
Weakest category	`min(domain_pct[0..5])`	%	Lowest-scoring domain — the bottleneck for tier progression.
Per-domain scores	`checkedW / totalW × 100` per domain	% each	Six individual domain percentages shown in category bars and radar chart.
Gap list	All applicable unchecked items, sorted by weight desc	item list	P1-Critical (W3) → P2-Important (W2) → P3-Standard (W1). Direct remediation input.
Tier badge / readiness	Implicit from overall% and gap count of W3 items	qualitative	A facility with zero W3 gaps and overall ≥75% is broadly tier-ready; formal certification still requires third-party audit.
Sensitivity ranking	`impact(item) = overall_if_met − overall_current`	Δ% each	Marginal overall-score gain from closing each gap. Guides where effort has the most impact.
Monte Carlo (PRO)	10,000 iterations, ±15% weight variance	mean / σ / P5–P95	Probabilistic score distribution accounting for measurement uncertainty in weight assignments.

06 Worked example

Enterprise facility, Tier 3 target. Assume the assessor marks all Electrical items met and none of the other five domains met (a degenerate stress-test to illustrate the weighting arithmetic). Electrical domain at Tier 3 Enterprise has 14 applicable items with a mix of W1–W3 weights; total domain weight = 35.

Electrical domain (only domain with any items met): checkedW_elec = 35, totalW_elec = 35 → domain_pct_elec = 100%
Other five domains: all 0% (nothing checked).
Weighted score sum: totalWeightedScore = 100×1.5 + 0×1.3 + 0×1.0 + 0×1.1 + 0×1.0 + 0×0.9 = 150
Max weight: totalMaxWeight = 100×(1.5+1.3+1.0+1.1+1.0+0.9) = 680
Overall: 150 / 680 × 100 = 22.1% → Grade F
Imbalance penalty: domain_pcts = [0,100,0,0,0,0], avg = 16.7, variance = (5×(0−16.7)² + (100−16.7)²)/6 = (5×278.9 + 6933.9)/6 ≈ 1388. σ = √1388 ≈ 37.3, imbalancePenalty = min(0.15, 37.3/200) = min(0.15, 0.187) = 0.15
CRI: 22.1 × (1 − 0.15) = 18.8 → Maturity L1 (Initial)
Weakest category: 0% (Site, Mech, Telecom, Fire, Security all at 0%)
Gap count: 46 total applicable items − 14 electrical items = 32 unmet items; sorted by weight for the remediation roadmap.

Engineering reading: even 100% Electrical compliance delivers only 22% overall due to the importance-factor weighting. A Tier 3 Enterprise facility needs balanced compliance across all six domains — Mechanical/Cooling and Site gaps are the next highest-impact domains to close after Electrical.

A more realistic scenario — Tier 3 Enterprise, all W3 items met but no W2 or W1 items:

Approximate W3 item count at Tier 3 Enterprise: 22 items across all domains (e.g. dual utility feeds, UPS, generator, ATS, VESDA, clean-agent suppression, access control, etc.).
Each domain: checkedW(d) ≈ domain's W3 weight sum; totalW(d) = domain's total weight sum including W2+W1 items.
Electrical domain illustration: W3 items weight ≈ 18 of 35 total → domain_pct_elec ≈ 51%
Aggregating across all domains in this scenario: overall ≈ 48–55% → Grade D to low-C
Gap list: all W2 and W1 items (P2 and P3 priority) — estimated 24 items to close.
This illustrates that meeting only Critical items places a facility at the borderline of Grade D — W2 items are essential to reach B-grade readiness.

07 References & standards

ANSI/TIA-942-B (2017) — Telecommunications Infrastructure Standard for Data Centers: six-domain structure, tier definitions, item-level requirements including floor loads, redundancy configurations, cable pathways, and fire systems referenced throughout the checklist (§5–§10).
Uptime Institute Tier Standard — Tier I–IV definitions for redundancy (N, N+1, 2N) and fault tolerance; used in the tier-level filter and concurrent-maintainability items.
BICSI 002-2019 — Data Center Design and Implementation Best Practices: supplemental design guidance for entrance rooms, MDA/HDA topology, and cabling management.
NFPA 70 (NEC) — National Electrical Code: referenced for EPO requirements (NEC 645.10/11), TGB/TMGB grounding (§6.5), and emergency lighting.
NFPA 101 — Life Safety Code: maximum travel distance for emergency egress, exit sign requirements (§9.4).
ASHRAE TC 9.9 — Thermal Guidelines for Data Processing Environments: A1 recommended envelope (18–27°C, 40–60% RH) and A2–A4 expanded envelopes used in mechanical domain items (§7.2, §7.3).
IEC 60364 — Low Voltage Electrical Installations: international basis for electrical system design and grounding.
TIA-568 — Structured Cabling Standard: cabling performance and installation requirements (§8.3.1).
TIA-607 — Telecommunications Grounding and Bonding: TGB/TMGB busbar requirements (§6.5).
TIA-606 — Administration Standard for Telecommunications Infrastructure: labeling standard (§8.6).
NIST 800-88 — Guidelines for Media Sanitization: referenced in secure decommissioning item (§10.9).

08 Assumptions & limitations

The checklist is a prescriptive yes/no self-assessment calibrated to ANSI/TIA-942-B section references. It does not perform engineering calculations (load sizing, airflow modelling, power-flow analysis) — those are handled by the complementary CAPEX, OPEX, PUE, and cooling calculators on this site.

Item counts and weights are fixed constants in the source code; they are not dynamically loaded or user-adjustable in free mode. The facility-type filter is a hard-coded dcTypes[] membership check — a facility spanning multiple types (e.g. a hyperscale colo) should run the assessment for each applicable type and compare.

Remediation cost estimates (W3 = $50K–200K, W2 = $10K–50K, W1 = <$10K) are broad order-of-magnitude benchmarks only. Actual costs vary by site, region, existing infrastructure baseline, and labour rates. The Monte Carlo ±15% weight variance models scoring uncertainty in the assessment process — it does not model cost uncertainty or construction risk.

This tool is an engineering education and pre-design aid. Formal TIA-942 certification requires an on-site audit by a TIA-942-accredited assessor. The checklist authors and ResistanceZero accept no liability for compliance decisions made solely on the basis of this tool.