How and when IIP computed?

How and when IIP computed?
The IIP estimate for a given month is always released within six weeks from that month.

The data for the IIP estimate is supplied by 15 source agencies which include Department of Industrial Policy and Promotion, Indian Bureau of Mines, Central Statistical Organisation and Central Electricity Authority, among others.

However, given the fact that all the data regarding production may not be available at the time the index for a particular month is being created, a provisional index is first created and released, which is then updated twice in the subsequent months.