Why management of change exists
Many serious incidents trace back to a change that nobody assessed: a bypassed interlock, a new chemical, a reorganised shift, a software update, a temporary fix that became permanent. MOC makes the question "what could this change affect?" a required step rather than an afterthought.
What counts as a change
- Equipment: new, modified, relocated or temporarily altered plant, including bypasses.
- Process: operating parameters, sequences, recipes, batch sizes.
- Materials: new raw materials, chemicals, suppliers or packaging.
- Systems: control software, data systems, alarms.
- Organisation and people: roles, staffing levels, shift patterns, contractors.
- Procedures: SOPs, standard work, permits.
Replacement in kind, like for like with the same specification, is usually exempt; everything else goes through MOC.
The MOC process
- Raise the change with a description, reason, scope and whether it is temporary or permanent.
- Assess the risks: hazards introduced or removed, effects on safety, quality, environment and operations, using a risk assessment or HAZOP as the change warrants.
- Define the controls and actions: engineering changes, procedure and training updates, communication, pre-start checks.
- Approve at the level matching the risk.
- Implement with the actions tracked to completion.
- Verify after start-up that the change performs as intended and the controls are in place, then close.
- Review temporary changes by their expiry date; extend formally or remove.
Common failures
- Temporary changes that are never closed.
- Approvals treated as signatures rather than reviews.
- Documents and training updated late or not at all.
- No check that the change worked before it is declared complete.
MOC and daily management
Open changes, their actions and their verification dates belong on the relevant tier boards, so the Tier 2 meeting sees a temporary bypass approaching its expiry and the Tier 3 review sees the changes awaiting verification.