Maintain process controller equipment within an engineered system used in food and drink operations

Business Sectors (Suites): Food and Drink
Developed by: Improve
Approved on: 26 Feb 2021


This standard identifies the competences you need to carry out corrective maintenance to process controller equipment within an engineered system used in food and drink operations, in accordance with approved procedures. You will be able to maintain a range of process controller equipment that typically includes process controllers or sequential controllers (including programmable logic controllers (PLCs), robots which are working in an integrated system involving interactive technologies: mechanical, electrical or fluid power. Food and drink operations is a term used in this standard to cover the following sub sectors of Meat, Drinks, Confectionery, Fresh Produce, Bakery, Seafood and Dairy.

This will involve dismantling, removing and replacing faulty peripheral components, process controller units, and components, down to board level on unitary' orrack' type process controller systems. You will also need to be able to load and download process controller programs, check them for errors, make alterations to programs, and create and maintain back-up copies of completed programs. The changing of programs should only be done so following design reviews ensuring that everything is documented and authorised.

You will be able to work with minimal supervision, taking personal responsibility for your actions, and for the quality and accuracy of the work that you carry out.

Performance criteria

You must be able to:

  1. work safely at all times, complying with health and safety, environmental and other relevant food and drink regulations, directives and guidelines
  2. plan and communicate the maintenance activities to cause minimal disruption to normal working
  3. obtain and use the correct issue of company and/or manufacturers' drawings and maintenance documentation
  4. select equipment and materials for maintenance activities
  5. check equipment has been safely isolated in accordance with organisational procedures (including mechanical, electricity, gas, steam, air or fluids)
  6. provide and maintain safe access and working arrangements for the maintenance area
  7. carry out the maintenance activities using appropriate techniques and in accordance with organisational procedures
  8. follow the relevant maintenance schedules to carry out the required work
  9. reconnect and return the system to service on completion of the maintenance activities
  10. report any instances where the maintenance activities cannot be fully met or where there are identified defects outside the planned schedule
  11. complete maintenance records and documentation in accordance with organisational procedures
  12. dispose of waste materials in accordance with safe working practices and approved procedures

Knowledge and Understanding

You need to know and understand:

  1. the health and safety and environmental requirements of the area in which the maintenance activity is to take place, and the responsibility these requirements place on you not to compromise food safety
  2. the isolation and lock-off procedure or permit-to-work procedure that applies to the system being worked on, including critical control points
  3. the isolation procedure which is specific to the process controller system being worked on
  4. the specific health and safety food and drink precautions that need to be applied during the maintenance activities, and their effects on others
  5. the requirements of the British Retail Consortium (BRC) guidelines and standards in relationship to the maintenance activities
  6. the specific requirements of your customer/client specifications in relationship to the maintenance activities
  7. your responsibilities in relationship to Hazard Analysis and Critical Control Points (HACCP), Threat Assessment and Critical Control Points (TACCP), Vulnerability Assessment and Critical Control Points (VACCP) during the maintenance activities
  8. what constitutes a hazardous voltage and how to recognise victims of electric shock
  9. how to reduce the risks of a phase to earth shock (including insulated tools, rubber mating and isolating transformers)
  10. the importance of wearing protective clothing and other appropriate safety equipment (PPE) during the maintenance activities, and where this can be obtained
  11. the procedures and precautions to be adopted to eliminate electrostatic discharge (ESD) hazards
  12. hazards associated with carrying out maintenance activities on a process controlled integrated system (including handling fluids, stored pressure/force, electrical supplies, process controller interface, using damaged or badly maintained tools and equipment, not following laid-down maintenance procedures), and how to minimise these and reduce any risks
  13. how to obtain and interpret drawings, charts, specifications, manufacturers' manuals, history/maintenance reports, symbols used on process controller documents, and other documents needed for the maintenance activities
  14. the basic principles of how the system functions, its operation sequence, the working purpose of individual units/components, and how they interact
  15. the principles of the equipment's design features for safe operation in a food or drink environment such as minimising the chance of contaminates or foreign bodies in the final product
  16. the devices and systems for storing programmes
  17. procedures to be applied to storage, location and method of backing up programmes
  18. the different types of interface cards, and their application
  19. the procedures for the application of computer-based authoring software for design and development
  20. the numbering system and codes used for identification inputs and outputs
  21. how to search a programme within the process controller for specific elements
  22. programming techniques and codes used (including interlocking, timers, counters, sub-routines)
  23. the techniques involved in editing, entering and removing contacts from lines of logic and, where applicable, the procedure to be followed for on' andoff-line' programming
  24. the procedure for obtaining replacement parts, materials and other consumables necessary for the maintenance, including their safe/hygienic storage before use
  25. company policy on repair/replacement of components during the maintenance activities
  26. the techniques used to dismantle/assemble integrated equipment (including release of pressures/force, proofmarking to aid re-assembly, plugging exposed pipe/component openings, dealing with soldered joints, screwed, clamped and crimped connections)
  27. methods of attaching identification marks/labels to removed components or cables to assist with re-assembly
  28. methods of checking that components are fit for purpose, and the need to replace items such as batteries, boards and other failed items
  29. how to check that tools and equipment are free from damage or defects, are in a safe and usable condition, and are configured correctly for the intended purpose
  30. the processes in place to segregate the tools and equipment used into high or low risk areas
  31. the checks required to ensure that all tools, materials and components are all accountable before operating the equipment
  32. the importance of making `off-load' checks before proving the equipment with the electrical supply on
  33. the cleaning requirements/policies in place before returning the equipment into full operational production
  34. the generation of maintenance documentation and/or reports on completion of the maintenance activity
  35. the equipment operating and control procedures to be applied during the maintenance activity
  36. how to use lifting and handling equipment in the maintenance activity
  37. the problems that can occur during the maintenance of the process controller system, and how they can be overcome
  38. the organisational procedure to be adopted for the safe disposal of waste of all types of materials including any spoilt food or drink products
  39. the extent of your own authority and to whom you should report if you have a problem you cannot resolve


Scope Performance

Scope Knowledge





Links To Other NOS

External Links

Version Number


Indicative Review Date

31 Jan 2024





Originating Organisation


Original URN


Relevant Occupations

Manufacturing Technologies, Plant and Machine Operatives, Process Operatives, Process, Plant and Machine Operatives

SOC Code



Food and drink; Engineering; manufacturing; maintenance; engineered system; integrated system; fluid power; pneumatic; hydraulic; vacuum systems; pumps; valves