Microbiological trending of environmental monitoring data serves multiple purposes:
- Trending helps to define and hone your limits
- Trending helps to determine if control of your processes has been lost (or is heading that way)
- Trending helps to identify the effectiveness CAPA and process ‘improvements’
In order to produce relevant trends, you need to have defined what your alert and action levels are and how many times in a row an alert constitutes an action. You also need to define how many below alert results may indicate an adverse trend. Basically you want to get what is heading out of control under control.
Data to trend includes all data collected from your viable environmental monitoring program. Showing these trends in graphs allows for easy identification of trends. As part of your trending, you should identify your top 10 microbe species detected within your production facility.
You need to have a defined trending and reporting period and reports need to be signed off both by the microbiologist and QA manager.
Your internal processes and documents will be dependent on which regulatory bodies have oversight at your facility.
A more detailed, though old post regarding trending can be read here.