How do you calculate an assembly complexity risk score?

Multiply the severity, occurrence and detection ratings on a consistent scale. Using severity 6, occurrence 4 and detection 3 gives the risk score shown, so higher totals flag the harnesses that most need error-proofing.

What is severity, occurrence and detection in this context?

Severity is how damaging a complexity-driven defect is if it escapes, occurrence is how often the complexity causes it, and detection is how likely current checks are to miss it. Higher detection scores mean worse detectability.

What is a good assembly complexity score?

Lower is better, but the number matters most relative to your other assemblies. Rank all harness variants and act on the top tier first; a high severity rating warrants action even when the total looks moderate.

Why multiply instead of add the three ratings?

Multiplication makes a single dominant factor - very high occurrence or poor detection - drive the score up sharply, which mirrors how a badly detectable frequent defect on a complex harness is disproportionately risky.

How is this different from a standard FMEA RPN?

It uses the same severity-times-occurrence-times-detection logic but is framed around assembly complexity drivers - splice density, connector variety, routing difficulty - rather than a generic failure mode, so it targets build-ability directly.

How do I reduce a high complexity score?

Attack the biggest factor. Lower occurrence by simplifying the design or adding fixturing, or lower detection risk with inline test coverage. Keep the scoring scale identical across variants so before-and-after comparisons stay honest.

Wire Harness, Cable & Electromechanical Assembly calculator

Assembly Complexity Score Calculator

Assembly Complexity Score is an FMEA-style risk number for wire-harness and electromechanical builds, combining how bad a complexity-driven failure is, how often it happens, and how likely you are to catch it before it ships. Process and quality engineers use it to rank which complex sub-assemblies - dense breakouts, tight splice counts, mixed connector families - deserve poka-yoke or design simplification first. It converts gut feel about a hard-to-build harness into a comparable, prioritizable number.

What this calculator does

Estimate assembly complexity for wire harness, cable and electromechanical assembly using production-ready inputs so teams can rank risks and decide which issue needs containment, controls, or escalation first.
Use it when assembly complexity in wire harness, cable and electromechanical assembly needs a defensible ranking against other wire harness, cable and electromechanical assembly risks for the next review.
It multiplies severity, occurrence and detection ratings into a single assembly-complexity risk score for ranking builds against each other.

Formula used

Assembly complexity risk score = assembly complexity severity score × assembly complexity occurrence score × assembly complexity detection score
Use the same scoring scale across comparable assembly complexity risks.

Inputs explained

Assembly failure severity rating:
Complexity-driven occurrence rating:
In-process detection rating:

How to use the result

Use it during process FMEA, design-for-assembly reviews, or when triaging which complex harness variants to error-proof first.
As a multiplicative score it hides its inputs - a low detection score can mask a life-safety severity - so always read the severity rating alongside the total, never the number alone.

Current U.S. benchmarks

The producer price index for copper and brass mill shapes stands at 559.593 (BLS, May 2026), up 76.8% from a year earlier. Quotes priced off last quarter's material cost miss this move. Global copper trades at $13,484 per tonne (IMF via FRED, May 2026).
Manufacturing hourly earnings average $30.27 (BLS, Jun 2026), up 4.4% from a year earlier. Median machinist pay is $28.24/hr (OEWS 2025), with state medians on each state page. Manufacturers have 529k open positions nationally (BLS JOLTS).
The U.S. has 5,397 electrical equipment and appliances establishments employing about 369,437 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate an assembly complexity risk score? Multiply the severity, occurrence and detection ratings on a consistent scale. Using severity 6, occurrence 4 and detection 3 gives the risk score shown, so higher totals flag the harnesses that most need error-proofing.
What is severity, occurrence and detection in this context? Severity is how damaging a complexity-driven defect is if it escapes, occurrence is how often the complexity causes it, and detection is how likely current checks are to miss it. Higher detection scores mean worse detectability.
What is a good assembly complexity score? Lower is better, but the number matters most relative to your other assemblies. Rank all harness variants and act on the top tier first; a high severity rating warrants action even when the total looks moderate.
Why multiply instead of add the three ratings? Multiplication makes a single dominant factor - very high occurrence or poor detection - drive the score up sharply, which mirrors how a badly detectable frequent defect on a complex harness is disproportionately risky.
How is this different from a standard FMEA RPN? It uses the same severity-times-occurrence-times-detection logic but is framed around assembly complexity drivers - splice density, connector variety, routing difficulty - rather than a generic failure mode, so it targets build-ability directly.

Last reviewed 2026-05-12.