Log Out /Tag Out with Simple Definition

Here is a example for your easy understanding  Log Out /Tag Out 

When anyone of you is doing a maintenance work on any of Electrical device in your house like checking a Tube light , or Cleaning of Refrigerator or Changing a holder of Bulb then the Main breaker of that Room section or house is use to be shut off so that there will be no current or power came in touch with the person working at Cleaning of refrigerator or Bulb Holder or etc.
Same it applies in industry just with the procedures which is called Log Out Tag Out.

Now Consider a electrician or a electrical team is changing the Bus Bar of a panel or a Transformer (A heavy metal plate which use to be connect with the Power coming from Grid or powerHouse ).
These bus bars are installed in the Transformers and Electrical panels which further is connected with Switches breakers (MCBs, GFCI) etc.

Now before the maintenance and work start at Panel or Transformer the area from the power is coming should be identified ,the team who is responsible for that area or a person who decide to allow the power to be supplied to that specific panel or transformer will shut off the supply Switch and will Install a lock and tag the switch (so that no other person can handle that switch even in his absence  as Lock and tag shows that maintenance is going on )on which all details are also mentioned.

The keys of the lock will be only with him and only he can remove the lock and tag once maintenance will be completed.

This person will be in touch with the maintenance team or person all the time until all work completed.

This all process will be documented when the process start who is the maintenance team who is person who have made locks and tag 
The time duration of Work , mobile numbers , wireless dialing numbers, shifts etc 

Same when in Pakistan a Team is working on High Transmission lines the Power from Grid is shut off this all process is called Lock Out Tag Out 

Please note it is not restricted or for Electric devices only also with Water Lines Hydrant Lines Fire pumps etc.

As per our latest DuPont audit . There are three keys for lock . One is with operation section . One is with Electrical section and one is for person who is performing job. Now please note that lock can only be open when three keys are applied simultanselouly. Or three locks to be installed. It will increase safety .