"You initiated investigation P201611001 for an initial OOS result of (b)(4) parts per million (ppm) in your (b)(4) residual solvent test (specification: not more than (b)(4) ppm) for (b)(4) API batch (b)(4). The investigation did not reveal laboratory testing anomalies. You tested another sample preparation three times and obtained results very close to the specification upper limit ((b)(4), and (b)(4)ppm). You invalidated the initial failing result, stating that your statistical analysis showed a significant difference between the original value and there test results. Your investigation lacked further assessment of the root cause of the failing result."