How do you calculate obsolete drawing risk?

Multiply three 1-10 scores: severity of building to a stale drawing, how often it occurs, and how likely you are to detect it first. With severity 6, occurrence 4, and detection 3 the calculator returns an RPN of about 4.55 on the normalized scale used here.

What is a good obsolete drawing risk score?

Lower is always better. There is no universal threshold, but teams typically set an action line (for example, review anything in the top quartile) rather than chasing an absolute number, because the value only means something relative to your other scored risks.

What drives a high obsolete-drawing RPN the most?

Detection usually dominates. If parts can be cut before anyone verifies the revision against the PLM system of record, your detection score stays high and the RPN climbs even when severity and occurrence are moderate.

How do I lower the score without redesigning the process?

Attack detection first: watermark obsolete PDFs, auto-expire cached drawings, and require a rev check at job release. Dropping a detection score from 6 to 3 halves the RPN with no change to severity or occurrence.

Is obsolete drawing risk the same as a full FMEA?

It uses the same severity x occurrence x detection math as an FMEA line item, but it is scoped to one specific failure mode. It complements a full PFMEA rather than replacing it.

What scale should severity, occurrence, and detection use?

Use one consistent 1-10 anchor set across every drawing-control risk you score. Mixing a 1-5 scale on one risk and 1-10 on another makes the RPNs incomparable and defeats the ranking purpose.

PLM, BOM & Digital Thread calculator

Obsolete Drawing Risk Calculator

Obsolete Drawing Risk is an FMEA-style Risk Priority Number (RPN) applied to a single failure mode: parts getting made to a superseded, uncontrolled, or obsolete drawing revision. Document controllers, PLM administrators, and quality engineers use it to rank which part numbers or workflows most urgently need revision-control fixes before scrap, rework, or an escape reaches the customer. It matters because a single stale print released to a CNC cell or a supplier can quietly produce hundreds of non-conforming parts before anyone notices. Scoring severity, occurrence, and detection on one consistent scale turns a vague 'we should tighten drawing control' into a defensible priority list.

What this calculator does

Estimate obsolete drawing risk for plm, bom and digital thread using production-ready inputs so teams can rank risks and decide which issue needs containment, controls, or escalation first.
Use it when obsolete drawing risk in plm, bom and digital thread needs a defensible ranking against other plm, bom and digital thread risks for the next review.
It multiplies your severity, occurrence, and detection scores into a single Risk Priority Number for the failure mode of building to an obsolete drawing revision.

Formula used

Obsolete drawing risk score = obsolete drawing risk severity score × obsolete drawing risk occurrence score × obsolete drawing risk detection score
Use the same scoring scale across comparable obsolete drawing risk risks.

Inputs explained

Severity if an obsolete drawing reaches the floor (1-10):
Likelihood a superseded drawing gets built to (1-10):
Chance the wrong revision is caught before machining (1-10):

How to use the result

Use it during a document-control audit, a PLM rollout, or a corrective action after a revision-mix-up escape, to rank which part families or release paths to harden first.
RPN is an ordinal ranking tool, not a probability. A 4.55 is not '4.55 times worse' than a 1.0, and two very different risks can share the same score, so always review the individual severity, occurrence, and detection numbers behind it.

Common questions

How do you calculate obsolete drawing risk? Multiply three 1-10 scores: severity of building to a stale drawing, how often it occurs, and how likely you are to detect it first. With severity 6, occurrence 4, and detection 3 the calculator returns an RPN of about 4.55 on the normalized scale used here.
What is a good obsolete drawing risk score? Lower is always better. There is no universal threshold, but teams typically set an action line (for example, review anything in the top quartile) rather than chasing an absolute number, because the value only means something relative to your other scored risks.
What drives a high obsolete-drawing RPN the most? Detection usually dominates. If parts can be cut before anyone verifies the revision against the PLM system of record, your detection score stays high and the RPN climbs even when severity and occurrence are moderate.
How do I lower the score without redesigning the process? Attack detection first: watermark obsolete PDFs, auto-expire cached drawings, and require a rev check at job release. Dropping a detection score from 6 to 3 halves the RPN with no change to severity or occurrence.
Is obsolete drawing risk the same as a full FMEA? It uses the same severity x occurrence x detection math as an FMEA line item, but it is scoped to one specific failure mode. It complements a full PFMEA rather than replacing it.

Last reviewed 2026-05-12.