SOP For out of trend is described in this post which you can follow in the section of the General Industry SOP.


To lay down the procedure for conducting an investigation of Out of trend (OOT) results observed during laboratory testing of samples.


This SOP is applicable to the out of trend results observed in the analysis of raw materials, packing materials, finished product, in-process samples, environmental monitoring results, water results and stability samples with respect to the previous stability test points conducted.


Officer Quality Control


Manager Quality Control

Manager Quality Assurance


  • Out of trend result shall be determined on the basis of the data of previous batches or previous analytical data or aberrant data observed during analysis. 
  • The result may be within the specification but not in the trend.
  • While performing the analysis, if any OOT data is observed, then the analyst shall immediately inform Manager QC and shall conduct the preliminary investigation along with the analyst of the OOT observation 
  • Executive shall store the sample and standard preparations and any other preparations used during the analysis until the investigation is completed.
  • Make the necessary entries in the OOT log (Annexure-II) by assigning the OOT No. as follows: OT/XX/ YYY


  1. OT: Out of Trend
  2. XX: Last two digits of the current year (e.g. for 2019 mention 19
  3. YYY : Sequential number (e.g. 001,002 ……)
  • During the above investigation, if the cause of OOT result is identified as laboratory error and Manager Quality Control conclude on it and repeat analysis shall be carried out and reported.
  • The same analyst shall repeat the test with a fresh sample and fresh standard preparation (if required) with due care to omit the errors identified.
  • In case if the cause of OOT result is not identified as laboratory error then Head QC shall recommend for reanalysis to confirm the OOT results. 
  • If the results of repeat analysis are similar to a previous analysis the OOT results are valid and the same shall be informed to the concerned departments.
  • The analyst shall record the re-analysis results in the worksheet.
  • If the reanalysis results are within the trend and observations are not aberrant, then the initial analysis shall be investigated for the cause of OOT and report the repeat analysis results.
  • If the cause of OOT results is not identified, and if the results of re-analysis are same as the previous analysis then the results obtained during the first analysis shall be reported.
  • If the test result is out of trend, it shall be concluded that the material/product is not meeting the trends and the final decision for acceptance of material/product shall be taken by Head Quality.
  • In the case of raw and packing material: Head Quality control shall review the OOT results and forward the same to QA and Supplier for investigation and prevent the recurrence of such incident in the future supplies.
  • In case of Finished Products: Head – Quality Control shall review the OOT results and forward the same to QA and Production for information and investigation. A final decision will be taken by the head Quality based on the investigation report.
  • In case of Stability studies: OOT investigations to be carried out and if required analysis can be performed using the samples of the previous stability test point. A final decision will be taken by the head Quality based on the investigation report in coordination with Production and R&D (If applicable).
  • If the product belongs to another customer where OOT is observed the same shall be informed to the product owner.