MOC should be conducted on both permanent and temporary changes.
- When discussion MOC, the changes are generally assumed to be permanent. MOC ensures that permanent changes are conducted without compromising the safety of the facility. But MOC is also used to control temporary changes.
- Temporary changes have caused several serious accidents in the past. They are included in MOC to ensure that all the safety considerations are addressed. They may not have same requirements as permanent change ,but when the change is being considered, the procedure used for a permanent change should be reviewed.
- Temporary changes must have a specified time limit – if it is later desired to extend this time, a new review should be conducted. MOC will keep track of the temporary changes and ensure that they are returned to their original conditions.
Some examples of temporary changes are:
- substitution of parts pending delivery
- system testing
- operate unit above specified design conditions to meet production quota
- replacement workers