HACCP Process Flow Diagram Verification Procedure

Plan verification around current process information

Verification starts with the product, product group or process that needs to be checked and the most recent approved version of its process flow diagram. The planning requirements bring together supporting information such as layouts and equipment lists, utility information, outsourced or subcontracted process details and relevant operational procedures.

The HACCP Food Safety Team determines whether the activity is routine or has been triggered by a defined change or incident, then agrees the timing, scope and personnel required. Verification is required during initial HACCP plan development, at defined intervals within the HACCP review cycle, following changes that may affect process steps or flow, and after incidents or deviations that indicate a diagram may no longer be accurate.

Walk the full process and compare the diagram with practice

On-site verification requires the HACCP Food Safety Team to walk through the full process represented in the diagram, from raw material receipt through to finished product dispatch. The team observes actual sequencing, delays, holding points and interactions, and confirms that each documented step exists in practice and is positioned correctly.

The check extends beyond the main processing sequence. It looks for omitted pre-processing or tempering stages, rework or recycling loops, holding, staging or buffering steps, and waste-handling or by-product flows. Relevant utilities and ancillary services are considered, together with subcontracted or off-site processes, zoning interactions where relevant, and alternative routes, seasonal variations or parallel lines where they exist.

These verification findings are documented as part of the verification record, giving the subsequent review a defined evidence base rather than relying on the diagram alone.

Test completeness, scope and process interfaces

After the on-site walkthrough, the HACCP Food Safety Team evaluates the diagram for completeness and accuracy. The review confirms that process steps are present, correctly described and in the right sequence, and that inputs and outputs such as raw materials, ingredients, water additions, rework, waste and intermediate or semi-processed products are represented.

The evaluation also checks relevant utilities and supporting services, outsourced or off-site activities, the boundary of the defined HACCP scope, zoning distinctions and line interactions. The finished diagram must be clear, logical and unambiguous for users. Any discrepancy or omission identified through this review is recorded.

Control diagram updates before HACCP review moves on

Where verification shows that an update is required, the procedure places the change under technical review and document control. Required amendments are drafted and reviewed for technical accuracy, updated diagrams are approved through document control, revised versions are issued and obsolete versions withdrawn, and relevant personnel are informed of the change.

The updated process flow diagram is then used in hazard analysis and subsequent HACCP review activities. Where re-verification is required, it must be completed before hazard analysis is repeated or updated. This preserves the sequence defined by the procedure: changes to the represented process are checked against actual operations before the revised flow is taken forward into the HACCP assessment.

Re-verify when changes could affect process flow or sequencing

The procedure defines a broad set of re-verification triggers where process steps, flow or sequencing may have changed. These include new products or formats, changes to raw materials or ingredients, altered process sequences, equipment additions or removals, layout changes, new holding or staging practices, changes to utilities or supporting systems, and new subcontracted or off-site activities.

It also captures changes in suppliers or material origins and outcome-based triggers such as deviations, incidents, emerging risks, internal audit findings and HACCP review outcomes. This keeps re-verification tied to defined changes and evidence that may affect the accuracy of the documented process flow.

Define ownership of verification, updates and supporting information

Responsibility is distributed across the functions that provide resources, operating information, document control and HACCP decision-making. Senior management provides sufficient resources, time and facility access, ensures relevant product, process, equipment and layout changes are communicated to the HACCP Food Safety Team, and supports corrective actions arising from verification findings.

Technical or quality management coordinates verification planning, scheduling, documentation and communication, provides access to current diagrams and supporting operational information, controls updated versions and reviews findings to ensure required updates are completed and approved. Department managers and functional leads provide accurate information about operational practices and changes, support access to production areas, equipment and personnel, and report changes that may require re-verification.

The HACCP Food Safety Team conducts the verification, confirms each diagram’s accuracy and completeness, records findings and required updates or corrective actions, and reviews and approves updates following verification. Personnel involved in verification or diagram updates are required to receive training appropriate to their roles in verification methods, on-site observation, documentation, record-keeping and change control.

Maintain evidence of the verified process flow

Records generated by the procedure may include verification checklists or reports, records of on-site walkthroughs, updated process flow diagrams and approval records, records of changes and actions arising from verification, and the supporting information used during the check.

Within the wider HACCP framework, this procedure complements the Process Flow Diagram Procedure by governing how the documented flow is checked against current operations. Its document-control and records interfaces support controlled updates and retained evidence, while the verified diagram provides the process information used in hazard analysis and subsequent HACCP review.