Flow diagrams and on-site confirmation

Step 4 asks for a flow diagram that covers all steps in the production of a specific product, including any rework. It should show all inputs, including ingredients, food contact materials, water and air, if relevant. Products with similar steps can share a diagram. Complex operations can be split into smaller linked modules.

Codex says flow diagrams should be clear, accurate and detailed enough for the hazard analysis. As appropriate, they should show the sequence and interaction of steps; where raw materials, ingredients, processing aids, packaging, utilities and intermediate products enter; any outsourced processes; where rework and recycling take place; and where end products, intermediate products, waste and by-products leave.

The diagram is the basis for evaluating the possible occurrence, increase, decrease or introduction of hazards. A site plan can help too, because it shows where people, equipment and food cross paths. This is often where cross-contamination and allergen cross-contact begin.

Step 5 asks you to confirm the diagram on site, during all stages and hours of operation, and to amend it where needed. A person or people with sufficient knowledge of the operation should do this. Do not just tick boxes. Ask what really happens. What do you do when the chiller is full? Where do returned trays go? What happens when the line breaks down? What changes at the weekend, when agency staff are on, or when the head chef is away?

In our example, the diagram showed the meat filling going straight from the kettle to the blast chiller. The confirmation walk found that on busy days, trays wait on a rack for up to an hour because the chiller is full. This waiting was a real step, and it was missing from the plan. The team added it to the diagram and took it into the hazard analysis. Chiller capacity had become a food safety issue, not just a production issue.

Sign and date the confirmed diagram. Treat it as a controlled document. Change it when the process changes.