Lockout Tagout :

To perform service and maintenance work on industrial equipment safely, you must understand the importance of energy control and OSHA's LOCKOUT / TAGOUT standards.

WHAT IS LOCKOUT / TAGOUT ( LOTO ) ?

A lockout is a method of preventing mishaps by keeping equipment from being accidentally started or switched off.
Lockouts are used for - disconnecting switches , circuit breakers , valves or other energy isolation mechanisms & to put them in the safe / off position. A lock is attached, so that the equipment can't be energized. In a Tagout, the energy-isolating device is placed in the safe position and a written warning is attached to it.