Audit Sample Sizes Clarification
| Entry Date | April 15, 2026 |
|---|---|
| Issue Number | 26-062-AIC |
| Name | Jack Johnson |
| Agency | Michigan State Police |
| Address | 7150 Harris Dr7150 Harris DrDimondale, Michigan, 48821United StatesMap It (opens in a new tab) |
| Phone | 2483316234 |
| [email protected] | |
| Committee | Audits and Investigations Committee |
| Status | Open |
| Summary of Issue | The safety audit manual is unclear when explaining required sampling sizes for DQ files, VM files, and Inspections used to calculate the OOS rate. eFOTM contains charts with the "minimum sample" and then language on how to document in Part C when the sample size isn't met or is exceeded. This language is confusing and contradictory on how a minimum sample can be exceeded. The SA manual does not refer the auditor back to the sampling chart in Appendix N, used for compliance investigators and leaves the issue open to interpretation whether the sample should stop at three or include all available drivers/vehicles operating under the carrier. Previous guidance from FMCSA SPS was to include all current drivers, CMV's, and carrier profile inspections in the previous 365. |
| Justification or Need | There is inconsistency in sample sizes. When conducting an onsite safety audit the sample size can impact the carriers pass/fail for OOS rate if all inspections in the previous 365 are included in the calculation bringing the calculation below the 34% threshold. |
| Request for Action | Request CVSA to obtain clarification from FMCSA for uniform sample sizes for DQ files, VM files, and Inspections used to Calculate the OOS rate. |