What is Management of Change and why do we need it?

Management of Change (MOC) is a systematic approach to ensuring changes to a process / facility do not introduce new hazards or increase the risks of existing hazards which are present in the process.

When proposed changes to an already existing process, facility design or operations are brought forward, a thorough review and evaluation should be carried out to ensure that the proposed changes have not created new hazards or increased the risk of existing hazards to the employees, public or environment.

MOC allows affected personnel on site e.g., operators of certain process in the facility, to be made aware of the changes being implemented through updated documentation such as Standard Operating Procedures (SOPs), P&IDs etc..

MOC should only be carried out for changes and not like for like replacements in a process. For example, changes in equipment design, changes in operating procedures, changes in inspection and test maintenance procedures and changes to the facility all require a MOC procedure.

The general basic steps to carrying out a MOC:

1. Recognise the proposed change(s)

2. Evaluate the hazards and risks

3. Determine if the hazards and risks can be reduced, controlled or eliminated

4. Determine if the change(s) can or should be made

5. Implement change(s) if it is safe to do so

6. Conduct Pre-Startup Safety Review (PSSR)

7. Train workers on the implemented changes

8. Follow procedures and continue to evaluate changes

Two examples of hazardous events which have occurred due to a failure in management of change are the Flixborough disaster in 1974 and the Bhopal gas tragedy in 1984.

The Flixborough disaster took the lives of 28 workers and injured a further 89 people due to an explosion involving 30 tonnes of cyclohexane. The explosions initiating event occurred due to a small change which was carried out by operators on site, where the operators temporarily bypassed a reactor which was leaking. Temporary piping was installed to bypass the reactor, however this was hastily done and the integrity of the temporary piping was eventually compromised which led to a release of cyclohexane.

The Bhopal gas tragedy of 1984 saw the release of Methyl Isocyanate which resulted in the death of thousands of lives in the surrounding area of the plant. The event occurred due to a runaway reaction which involved water leaking through a jumper line into a Methyl Isocyanate storage tank. One key factor in this incident was the lack of hazard assessment carried out to assess the changes in installing the jumper line.

Ryan Roche is a Process Safety Engineer at OTECSA Consulting with expertise in hazard studies, DSEAR and hazardous area classification.