What Is Failure Reporting Analysis And Criticality Analysis (fmeca)?

Failure Reporting Analysis and Criticality Analysis (FRACAS) is a closed-loop reliability process that systematically captures every failure event, determines its root cause, and implements and verifies a corrective action to prevent recurrence. FRACAS ties together the documentation of observed failures (Failure Reporting), the investigation of their causes (Analysis), and the implementation and verification of fixes (Corrective Action) into a single traceable cycle. When integrated with Failure Mode Effect and Criticality Analysis (FMECA), which ranks failure modes by their combined probability and severity before failures occur in the field, the two methods create a continuous improvement loop: FMECA guides what to watch for, and FRACAS captures what actually happens and feeds that evidence back into updated risk assessments.

The U.S. Department of Defense formalized FRACAS requirements for defense systems in the 1980s, requiring contractors to maintain a closed-loop failure data system as part of reliability qualification programs. Those requirements propagated into commercial practice through the aerospace, medical device, and industrial equipment sectors.

The FRACAS Cycle

The FRACAS process moves through three sequential phases for every failure event. In the failure reporting phase, a standardized report is created for each failure, capturing item identity, operational context, environmental conditions, symptoms, and failure mode characterization. The report enters a central database where it is assigned a tracking number and routed for investigation.

In the analysis phase, engineers apply root cause analysis techniques to determine the physical or logical cause of the failure. Methods such as the five-why interrogation, fault tree analysis, and Pareto prioritization identify whether the failure resulted from a design deficiency, a process anomaly, a use-condition outside the design envelope, or a combination of factors. Physics of failure modeling provides a mechanistic framework for connecting the observed failure symptom to the specific degradation process that caused it, improving the accuracy and completeness of root cause determinations.

In the corrective action phase, engineering changes are proposed, reviewed, implemented, and verified. Verification confirms that the corrective action actually reduced or eliminated the failure mode without introducing new ones. The FRACAS record is closed only when verification evidence demonstrates that the corrective action was effective.

Integration with FMEA, FMECA, and Six Sigma

FRACAS data serves as the empirical feedback that updates the probabilistic estimates in FMEA and FMECA. Failure modes that were assigned low occurrence probability during design analysis may appear at significant rates in FRACAS data, triggering a revision of the FMEA occurrence rating and a corresponding increase in the risk priority number. Conversely, corrective actions that successfully eliminate a failure mode reduce its FMECA criticality, allowing resources to be redirected to remaining high-criticality modes.

IEC 60812, the standard governing FMEA and FMECA procedure, supports this integration by specifying that FMEA documents should be living records updated with in-service experience. Six Sigma DMAIC programs use FRACAS data as the measured response in the Measure and Analyze phases, with Pareto analysis of failure report populations identifying the failure modes that drive the largest fraction of defects and directing improvement projects toward the highest-impact targets.

Environmental Stress Screening results also feed into the FRACAS cycle: units that fail screening are documented, analyzed to confirm the failure mode, and tracked to ensure that the corrective action applied to the design or process eliminates the failure mode from future production lots.

Statistical Methods and Failure Rate Tracking

FRACAS databases accumulate the failure count and operating time data needed to compute empirical failure rates for specific failure modes. NIST reliability analysis methods provide the statistical tools to estimate failure rates and confidence bounds from field return data, enabling engineering teams to determine whether the observed failure rate for a specific mode is consistent with design predictions or represents an unexpected reliability shortfall requiring further investigation.

Applications

FRACAS and integrated FMECA programs have applications across a range of industries, including:

• Aerospace and defense hardware qualification and sustainment
• Medical device post-market surveillance and corrective and preventive action programs
• Semiconductor manufacturing defect tracking and process improvement
• Automotive warranty management and field quality engineering
• Nuclear and industrial safety instrumented system reliability assurance