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Operating procedures

This Technical Measures Document refers to Operating Procedures.

Related Technical Measures Documents are:

The relevant Level 2 Criteria are:

General principles

There have been numerous recorded incidents where failings by operators have been the major contributing cause of major accidents. Provision of clear, concise and accurate operating procedures is the most effective measure to prevent, control and mitigate such events.

Operating procedures should clearly lay down instructions for operation of process plant that take into consideration COSHH, manual handling, permit to work, PPE Regulations, quality, HAZOP, and SHE requirements. The procedure should represent a definition of good or best practice that should be adhered to at all times. Process operatives should be provided with guidance concerning the required operating philosophy to ensure that they comply with procedural requirements.

Adequate training should be provided to ensure that operators are fully conversant with written procedures. This is covered in the Technical Measures Document on Training.

It is important that operating procedures should always reflect plant practice, and vice versa.

Provision of Comprehensive Written Operating procedures

Comprehensive written operating procedures should be generated where applicable that address:

These procedures should cover the following:

  • Plant operatives should have an awareness and understanding of material safety data for raw materials, intermediates, products and effluent / waste;
  • The condition of main process plant and equipment (clean, empty etc. as appropriate) should be established as being fit for purpose;
  • The condition of ancillary process plant and equipment (clean, empty etc. as appropriate);
  • Monitoring and recording of key process parameters (temperature, pressure etc.) in plant logs;
  • Sampling of raw materials, intermediates, products and effluent/waste;

Operating procedures should be controlled documents, generally covered under the company’s quality system and thus kept fully up to date. Any changes should be fully controlled and documented and should be subject to company change procedures (see Technical Measures Document on Plant Modification / Change Procedures). Standard operating procedures may be revised for the following reasons:

Limits of Intervention, Control Systems Interface

Clear demarcation of where limits of intervention cease and reliance upon the control systems interface begins is a critical step in defining the operating procedures for a given plant or process. During the hazard and operability stage, the justification of reliance upon human intervention rather than automated systems should be established. This should be assessed in more depth in a subsequent risk assessment.

Commissioning procedures

Commissioning of process plant is the practical test of the adequacy of prior preparations, including training of operating personnel and provision of adequate operating instructions. Since the possibility of unforeseen eventualities cannot be eliminated during this period when operating experience is being gained, the need for safety precautions should be reviewed. This should form part of the HAZOP / Risk Assessment processes applied to the installation. Full written operating instructions should be provided for all commissioning activities.

Commissioning Procedures document a logical progression of steps necessary to verify that installed plant is fully functional and fit for purpose. A general sequence of steps in commissioning may typically include:

Each section should be read in detail to gain understanding about the particular requirements of the activity prior to undertaking the activity itself and completing the associated check list. The checklist will serve as a permanent record of the activity, and can be reviewed if future modifications are undertaken.

It is assumed that prior to the commencement of commissioning activities that full support from plant personnel has been obtained.

Start-up / shutdown procedures

Many potential hazards can be realised during start-up or shut-down of plant or process. Specific operating procedures should be provided which take account of all eventualities. For some specific plant items, start-up is know to present particular additional hazards; some examples of these are:

The start-up and shut-down procedures should be ordered and phased so that interlinked plant operations can resume or cease in a safe and controlled manner.

Emergency procedures

Further information can be found in the Technical Measures Document Emergency Response / Spill Control.

Any potential deviations to normal operation that cannot be addressed by design or control identified in the Hazard and Operability studies should be covered by emergency procedures. These should detail how to make plant and process safe, minimising risks to operators at all stages. They should cover PPE, the level of intervention which is safe and when to evacuate. The procedures will need to tie in closely with the on and off-site emergency plans provided under COMAH.

Management / supervision

A clear management structure should be in place that defines competent responsible person(s) for generation of operating procedures and supervision of plant and personnel. The role of the supervisor in terms of training of operators, overseeing certain critical operations and checking of logs and other activities to ensure compliance with operating procedures. This should fulfil the requirements of the company’s health and safety policy.

Human factors

The appropriate design of a procedure is critical in the reduction of human error within process operations. The benefits of procedures are that they can aid an operator when they are faced with a complex diagnosis, or they can act purely as an aide memoir during non-critical routine operations.

The following section provides human factors guidance on the production and implementation of procedures.

Generally there are four types of procedure:

Each of the procedure types listed above all conform to the same general human factors principals. These are discussed below.

Task analysis

The content of important procedures should be based on some form of formal task analysis method to ensure that the procedure accurately describes the task it refers to. On some plants a process may have a safety-related action or task that has become an accepted ‘unofficial’ part of the procedure, but which is not documented anywhere. In this situation the task analysis will pick up on this and allow it to be incorporated into the procedures. Conversely, any dangerous actions that an operator might routinely carry out will also be detected.

The most commonly used method of task analysis is Hierarchical Task Analysis (HTA). Further information on this method and others can be found in ‘ A Guide to Task Analysis edited by B. Kirwan and L. K. Ainsworth.

Operating instructions should be close to the user and kept up to date. The following issues should be considered in assessing operating procedure documentation:

More detailed information can be obtained from the Further Reading Material outlined in the section below.

Validation

A procedure should always be formally validated prior to it being issued. The best method to achieve this is a comprehensive walk-through assessment of the procedure in the plant, or with reference to the relevant plant drawing when an in plant assessment is not possible.

Status of guidance

Guidance related to operating procedures tends to be non-specific, i.e. operating procedures are covered in sections of existing guidance. However, no guidance is currently available that specifically addresses operating procedures and related issues. Consequently the quality and standard of operating procedures can vary between different companies, and also within the same company if multi-process plants are in operation.

Codes of Practice relating to Operating procedures

Further reading material

ILO, PIACT, Major Hazard Control: A practical manual, 1988.

ILO, Conditions of work digest, Preventing Stress at Work, 1992.

Lees, F.P., 'Loss Prevention in the Process Industries: Hazard Identification, Assessment and Control', Second Edition, 1996.

Section 6.5 provides guidance on Systems and Procedures;

Section 13 provides guidance on Control System Design;

Section 14 provides guidance on Human Factors and Human Error;

Section 19 provides guidance on Plant Commissioning and Inspection;

Section 20 provides guidance on Plant Operation;

Section 24 provides guidance on Emergency Planning.

Kirwan, B. and Ainsworth, L. K. eds., ‘A Guide to Task Analysis’, Taylor and Francis, London, 1993.

Ball, P. W. ed., ‘The Guide to Reducing Human Error in Process Operations’, HFRG, The SRD Association, AEA Technology, 1985.

Case studies illustrating the Importance of Operating procedures

2010-03-11