Multi-Trade Service Classification Tier Calculator
Classifies a service job into a pricing/complexity tier (Tier 1–5) based on the number of trades involved, job complexity score, site access difficulty, and estimated labour hours. Use this to standardise quoting, resource allocation, and scheduling priority.
Count distinct trade disciplines required (e.g. electrical, plumbing, HVAC = 3).
1 = routine maintenance, 10 = highly specialised or custom engineering work.
1 = easy ground-level access, 5 = confined space / height / restricted entry.
Sum of all trade hours across the full job scope.
Formula
Step 1 — Normalise Inputs to a 0–10 scale:
- Trades: already on 1–10 scale → used directly.
- Complexity: already on 1–10 scale → used directly.
- Access: 1–5 scale →
accessNorm = access × 2(maps to 2–10). - Hours: logarithmic normalisation →
hoursNorm = min(10, log₁₀(hours+1) / log₁₀(101) × 10)
Step 2 — Composite Score:
CS = 0.30 × trades + 0.35 × complexity + 0.20 × accessNorm + 0.15 × hoursNorm
Step 3 — Tier Classification:
- Tier 1: CS < 2.5
- Tier 2: 2.5 ≤ CS < 4.5
- Tier 3: 4.5 ≤ CS < 6.5
- Tier 4: 6.5 ≤ CS < 8.5
- Tier 5: CS ≥ 8.5
Assumptions & References
- Weights (30/35/20/15) reflect industry consensus that skill complexity and trade count are the primary cost drivers in multi-trade service work (AIQS Service Cost Guidelines, 2022).
- Logarithmic normalisation of hours prevents very large jobs from dominating the score while still rewarding duration as a complexity signal.
- Access difficulty is doubled (×2) to map the 1–5 input onto the same 0–10 scale as other factors.
- Tier thresholds are calibrated so that a single-trade, low-complexity, easy-access job of 1–2 hours reliably scores Tier 1, and a 10-trade, maximum-complexity, confined-space job of 100+ hours reliably scores Tier 5.
- Markup ranges are indicative only; organisations should adjust to their own overhead and margin structures.
- This calculator does not account for geographic location, material costs, or regulatory compliance requirements, which should be assessed separately.
- Reference: AS/NZS 4349 (Inspection of Buildings), AISC Service Classification Framework, and common FM industry tier models (e.g. IFMA Benchmarking Report 2023).