Preparatory Stage G: Construct a flow diagram


A process flow diagram shows all the steps involved in the process outlined in the Scope of the study (Preparatory Stage C).

How is this stage achieved?

The HACCP team or person leading the development of the HACCP study should construct a flow diagram.  Whatever format chosen to do this,  all steps in the process outlined in the Scope of the study should be included.

You may wish to use a schematic layout of the factory to help you but knowledge of what actually occurs is essential.

  • List each step in the process/module typically from receiving the raw materials intake to at least despatch or to point of final consumption.  Think about:

    • Preparation
    • Packing
    • Storage
    •  Distribution
  • You could also consider the following:

    • Raw material addition (including water)
    • Services (air, water, steam)
    • Any temporary product storage or hold periods (particularly during peak production times)
    •  Recycle / rework loops
    •  Process delays

Draw a rough paper sketch of the product flow.  Consider the way in which the process is managed and what could realistically occur i.e. optional and or intermittent activities.

The inclusion of relevant technical data will depend on the complexity of the operation.  This data is useful at the Critical Control Points that you will identify later.  Technical data could include:-

  • Time  for process or process element (e.g. fry for 2 minutes at 1900C or cool to <50C in 4 hours)

  • Temperature at different parts of the process (e.g. fry at 1900C  for 2 minutes or cool to <50C in four hours)

  • Line speed

  • Floor plan, equipment and services layout

  • Segregation of low/high risk operations

  • Personnel routes

  • Flow conditions for liquids and solids (psi=pounds per square inch or temperature in 0C)

  • Waste flows

  • Movement routes for raw materials/ingredients

A piece of equipment may have several functions (e.g. a bottle filling machine including rinsing, volumetric/gravity/vacuum/hot fill and capping functions).  All functions should either be included in the description at the process step OR each function entered as a different process step.