5.7. Aspects of the practical operation of the system
The concept is shown in Fig. 6. The figure shows a simplified fish SC. It can be seen that the data is passed from the SC, preferably in continuous fashion, at selected intervals through the SC information system to the DSS. The frequency with which environmental parameters are passed to the DSS depends on how rapidly these parameters can change. For example, at the beginning of the SC, information on pH and NaCl% would be required. Later in the SC measurements of NaCl% are not required unless food processing takes place, which could change NaCl content. pH would slightly change with time, therefore, if the QMRA model includes pH it would have to be recorded. The temperature is the parameter which can change more rapidly than the other parameters and is also more important than the other parameters so it would be recorded with higher frequency.
Though HACCP should be implemented in the whole SC, normally different SC operators implement the HACCP at CCPs which are located in their part of the SC. SC operators implementing HACCP will be able to receive the data from the SC directly at the point where they are and from the DSS for the whole SC. They will receive the results of analysis performed by the QMRA and will follow the procedures to protect the consumers’ health. Among the actions that might be taken we mention here: removal of the product from the supply chain, keeping the product in the supply chain while acknowledging shorter shelf life, or, for uncooked meat products, redirection to a processing plant, e.g., for production of pet food. The classical HACCP works with critical limits, but in this case there are also results of analysis which show in more accurate way the probability for certain risk level to the consumer at time of purchase/consumption of the product. The critical limits may not be sufficiently clear indicators of the safety of the product in certain point in the SC if the previous temperature in the SC up to that point is not analyzed. Therefore it may happen that the DSS shows that the risk is increased, based on the available data up to that point in the SC though the HACCP shows that everything is normal since the limit/s has/ve not been exceeded at the CP, and vice versa. The DSS may conclude that despite slight temperature abuse in certain part of the SC the product is still safe for consumption, though the HACCP will consider the product unsafe since the critical limits have been exceeded. Such conflicts would require further attention in order to be resolved. This would most likely involve more extensive testing than the routinely performed one in order to determine whether the product is safe. The data obtained may be used to adapt the HACCP which will resolve such conflicts in the future. Though it seems as if such system would introduce conflicting situations, such system would be more reliable than a system which is based on a single approach, HACCP or QMRA. Since HACCP and QMRA are based on different principles, qualitative and quantitative, respectively, the probability that both systems fail (give wrong estimate) at same instance is minimal.