What a mock drill is and how to conduct it? How many types of mock drills do we have in safety?

Dear sir, Pls tell me - what a mock drill is and how to conduct it? How many types of mock drills do we have in safety, and whether every mock drill should be conducted once a year, or how many times should we conduct it? For this mock drill, should we get permission from government

There will be safety rules given by every Government.
Where large number of people are employed in any industry,office an evacuation plan should be in place and practised t least once a year.
Obviously the type of product the factory makes will be important.
If there are hazardous processes,specific plans for fire,explosions will be needed.
Check with the government department which controls your industry.
Hospitals,nearby police station,fire station will need to be kept in the loop for exercise of mock evacuation.
Detailed plan for various contingencies-fire,explosion,terror attack will have to be drawn up,how the guards have to react,where staff will assemble after evacuating the main building.Plans broken down to small steps need to be made and desimated to HODs etc.
Subject is vast but veruy important in case any eventuality takes place.