Glossary

Key terms used in Specwarden reports and documentation, listed alphabetically.

Action Priority (AP)

AIAG-VDA §2.5.10 lookup table output (H/M/L) replacing RPN as the primary risk metric. Action Priority is determined by a combination of Severity, Occurrence, and Detection ratings using the AIAG-VDA reference table rather than simple multiplication.

AIAG-RPN

Legacy AIAG 10-column DFMEA format using Risk Priority Number (S × O × D) as the risk metric. Still widely used in automotive supply chains, particularly where AIAG-VDA adoption is incomplete.

AIAG-VDA

2019 AIAG-VDA Handbook 16-column DFMEA format using Action Priority (AP) lookup table. The jointly developed standard between AIAG and VDA supersedes the legacy AIAG format for new DFMEA development at most OEMs.

Closed-loop validation

AIAG-VDA §2.6.3 requirement to verify post-action revised ratings are populated and correct. A DFMEA passes closed-loop validation when every row with a completed action has revised Severity, Occurrence, and Detection ratings, and the revised AP is consistent with those ratings.

D-001b (Tier-2 supplier-blame)

A DFMEA Failure Cause that blames the upstream supplier's execution rather than naming a design-specification gap. Example: "Supplier delivers out-of-spec material" is a supplier-blame cause; the correct form names the specification tolerance or interface requirement that is insufficiently defined.

Detection (D)

Rating 1–10 indicating how likely the current design controls are to detect the failure before it reaches the customer. A rating of 1 means detection is almost certain; 10 means detection is unlikely. Detection ratings can be reduced by adding or improving design controls.

DFMEA

Design Failure Mode and Effects Analysis — systematic analysis of how design elements can fail and the effects on the customer. DFMEA evaluates risks inherent to the design, not to the manufacturing process (see PFMEA). Specwarden V1 supports DFMEA and PFMEA; Control Plan ships in V1.5.

Occurrence (O)

Rating 1–10 indicating the likelihood that the failure cause will occur. A rating of 1 means the cause is extremely unlikely; 10 means it is almost inevitable. Occurrence can be reduced by design changes that eliminate or reduce the root cause.

PFMEA

Process Failure Mode and Effects Analysis — covers manufacturing and assembly process failures, distinct from design failures. PFMEA is supported in Specwarden V1 alongside DFMEA. Control Plan review ships in V1.5.

RPN

Risk Priority Number = Severity × Occurrence × Detection (1–1000). Legacy metric used in the AIAG-RPN format. Replaced by Action Priority in AIAG-VDA. RPN is still calculated and displayed by Specwarden when reviewing AIAG-RPN format files.

Severity (S)

Rating 1–10 indicating the severity of the failure effect on the customer. Severity is design-intrinsic: it reflects the worst potential consequence if the failure mode occurs. Under AIAG-VDA, Severity cannot be reduced by engineering actions alone — only a design change that eliminates the failure effect can change the Severity rating.

Standard reference

The AIAG handbook section or rule ID cited for each Specwarden finding, e.g., AIAG §4.2.1 or AIAG-VDA §2.5.10. Standard references allow reviewers and engineers to locate the normative requirement behind each finding without purchasing separate documentation.