How do you calculate supplier long-lead risk?

Multiply the three scores: severity times occurrence times detection, each on a common scale. In the default, 6 x 4 x 3 gives a raw product; the calculator normalizes to a comparable risk score of about 4.55 for ranking against other items.

What is a good supplier long-lead risk score?

Lower is safer. There is no universal threshold, but items landing in the top quartile of your scored list are the ones to expedite or dual-source. Rank relatively across your bill of long-lead items rather than chasing an absolute cutoff.

Why multiply the scores instead of adding them?

Multiplication rewards items that are bad on several dimensions at once. A part that is high severity, high occurrence, and hard to detect early compounds into a much larger number than any single factor, which is exactly the profile you want surfaced first.

What does the detection score capture for procurement?

It reflects how early you would see a slip coming. A supplier with a live production dashboard and milestone reporting scores low (easy to detect); a black-box vendor who only tells you at the promised ship date scores high (hard to detect, more dangerous).

How is this different from a standard FMEA?

The math is the same RPN structure, but the failure mode is procurement slip, not a part defect. Severity is schedule impact, occurrence is supplier reliability, and detection is your visibility into their progress rather than an inspection gate.

How often should long-lead risk be re-scored?

At award, and again at every major schedule review or when a supplier signals trouble. Occurrence and detection change as you build relationships and reporting; a re-score after the first milestone often moves items materially.

Tunnel Boring & Heavy Civil Equipment calculator

Supplier Long-Lead Risk Calculator

Long-lead items are the silent killers of tunnel and heavy civil schedules: a main bearing, a VFD drive, a segment mould, or a custom cutterhead can carry a lead time measured in months, and one slipped delivery can idle an entire drive. This calculator adapts FMEA logic to procurement, multiplying how bad a late delivery would be (severity), how likely the supplier is to slip (occurrence), and how blind you are to that slip until it lands (detection). Procurement leads, project controls, and TBM planners use the resulting risk number to rank items for expediting, dual-sourcing, or early buffer stock. It turns a gut feeling about a shaky supplier into a comparable score you can act on.

What this calculator does

Estimate supplier long-lead risk for tunnel boring and heavy civil equipment using production-ready inputs so teams can rank risks and decide which issue needs containment, controls, or escalation first.
Use it when supplier long-lead risk in tunnel boring and heavy civil equipment needs a defensible ranking against other tunnel boring and heavy civil equipment risks for the next review.
It multiplies severity, occurrence, and detection scores into a single supplier long-lead risk priority number for ranking critical procurement items.

Formula used

Supplier long-lead risk score = supplier long-lead risk severity score × supplier long-lead risk occurrence score × supplier long-lead risk detection score
Use the same scoring scale across comparable supplier long-lead risk risks.

Inputs explained

Long-Lead Item Impact Severity (1-10):
Late-Delivery Likelihood (1-10):
Early-Warning Detectability (1-10):

How to use the result

Use it during procurement planning and supplier qualification, and re-run it whenever a supplier's status or a schedule float changes.
The multiplicative score can mask a dangerous single dimension; a part with catastrophic severity but low occurrence gets a modest number even though a rare miss would still stop the drive, so read the individual scores, not just the product.

Current U.S. benchmarks

Steel mill PPI stands at 348.53 (BLS, May 2026), up 6.7% from a year earlier. New factory orders are up 2.3% year over year (Census).

Common questions

How do you calculate supplier long-lead risk? Multiply the three scores: severity times occurrence times detection, each on a common scale. In the default, 6 x 4 x 3 gives a raw product; the calculator normalizes to a comparable risk score of about 4.55 for ranking against other items.
What is a good supplier long-lead risk score? Lower is safer. There is no universal threshold, but items landing in the top quartile of your scored list are the ones to expedite or dual-source. Rank relatively across your bill of long-lead items rather than chasing an absolute cutoff.
Why multiply the scores instead of adding them? Multiplication rewards items that are bad on several dimensions at once. A part that is high severity, high occurrence, and hard to detect early compounds into a much larger number than any single factor, which is exactly the profile you want surfaced first.
What does the detection score capture for procurement? It reflects how early you would see a slip coming. A supplier with a live production dashboard and milestone reporting scores low (easy to detect); a black-box vendor who only tells you at the promised ship date scores high (hard to detect, more dangerous).
How is this different from a standard FMEA? The math is the same RPN structure, but the failure mode is procurement slip, not a part defect. Severity is schedule impact, occurrence is supplier reliability, and detection is your visibility into their progress rather than an inspection gate.

Last reviewed 2026-05-12.