The purpose of monitoring is to assure that processes stay within the critical limits for each hazard. Monitoring also allows operators to track measurements and signal when an adjustment might be needed to avoid going out-of-control. The written documentation from monitoring is proof that the product has been produced safely.
There are four elements for monitoring:
- What to monitor
- How to monitor
- When to monitor (the frequency)
- Who will monitor
Many different parameters can be monitored depending on the process. Some examples include:
- Line speed
- Depth of peanuts in the roaster
It is best to monitor continuously using sensors or instruments, but when this is not feasible, monitoring should be timed based on the variability of the process, how close normal values are to critical limits, and how much product is at risk if the critical limit is exceeded.
Monitoring should be performed by employees who are trained in monitoring procedures and understand the importance of monitoring. They should also be trained in what to do if the process does not meet a parameter.
Here is the roasting example again. Monitoring includes measuring the time the nuts are in the roaster using a stopwatch to calibrate with the line speed, a leveling bar to find the height in the oven and a thermometer to track temperature in the oven. The roaster operator should check each of these devices and record each time he checks.