Detailed Breakdown
1. Deviation
- Definition: Any departure from a written procedure, standard, or instruction.
- Types:
- Planned Deviation: A temporary, pre-approved change. (e.g., “We are out of Filter A, so we have permission to use Filter B for this batch only.”)
- Unplanned Deviation: An accidental error. (e.g., “The operator set the machine speed to 50 RPM instead of the required 60 RPM.”)
- Key Trigger: The standard was not followed.
2. Incident
- Definition: An unplanned event or breakdown that may not initially classify as a deviation but affects the environment or operations.
- Nuance: Some companies treat “Incident” as a “soft deviation” or a minor operational failure.
- Examples:
- A water pipe leaks in the corridor (not directly on the product).
- Software crashes during data entry.
- Key Trigger: An unexpected event occurred. (If the event affects the product, it often escalates into a Deviation).
3. OOS (Out of Specification)
- Definition: A laboratory test result that falls outside the pre-established acceptance criteria (specifications).
- Scenario:
- Specification: Tablet hardness must be between 5 kg and 10 kg.
- Result: The tablet hardness is 4 kg.
- Key Trigger: The result failed the official limit. This requires a mandatory, rigorous investigation (Phase I & Phase II) to see if it was a lab error or a manufacturing failure.
4. OOT (Out of Trend)
- Definition: A test result that is within the specification limits but generally disagrees with historical data or expected trends.
- Scenario:
- Specification: Assay (Purity) must be 95% – 105%.
- Historical Trend: The last 50 batches have all been between 99% and 100%.
- Result: The new batch is 96%.
- Why it matters: Even though 96% is a “passing” score (it is inside the 95-105 limit), it is statistically unusual. It suggests the process is drifting and might fail (OOS) soon if not fixed.
- Key Trigger: The result is unusual compared to the past.
Summary of the Relationship
You can visualize the flow of these problems as follows:
- Incident: The AC breaks down in the warehouse (Event).
- Deviation: Because the AC broke, the temperature exceeded the SOP limit of 25°C for 2 hours (Process Violation).
- OOT: You test the product stored there. The result is valid, but lower than usual stability (Warning).
- OOS: You ignore the warning. Two months later, the product fails the test completely (Failure).
Would you like me to explain the specific “Phase I vs. Phase II” investigation steps required when you get an OOS result?