The Industrial Output data is captured and monitored, primarily, through two statistical activities (i) Annual Survey of Industries (ASI) on an annual basis and (ii) Index of Industrial Production (IIP) on a monthly basis. The ASI is conducted under the Collection of Statistics Act, since 1959, to obtain comprehensive and detailed statistics of industrial sector with the objective of estimating the contribution of registered manufacturing industries as a whole to the national income. The IIP is compiled on the basis of data sourced from 16 ministries/ administrative departments. Data for IIP are collected by various source agencies under different Acts/statutes. Data received then undergo scrutiny and validation before finalisation.

The output figures for compilation of IIP are authenticated by respective line Ministries/ departments and the ASI data is based on actual book of accounts and other documents maintained by registered factories. Government is not contemplating any changes in the process for obtaining this data. The improvement in statistics pertaining to industrial output is a dynamic process and quality of data is reviewed from time to time by expert groups/ standing committees to note the change in structure of industrial sector of the country, and improvements are made on the basis of recommendations of these committees/ expert groups.

This information was given by the Minister of State (Independent Charge) in the Ministry of Commerce & Industry Smt. Nirmala Sitharaman in a written reply in Rajya Sabha.

Statutory basis for industrial statistics: survey and administrative data combined, validated and authenticated before finalisation. Industrial output measurement relies on two mechanisms: the Annual Survey of Industries, conducted on a statutory basis using factory books of account to estimate manufacturing contribution to national income, and the Index of Industrial Production, compiled monthly from administrative data supplied by multiple ministries; both data streams undergo scrutiny, validation and authentication by source agencies and line ministries before finalisation, with quality and methodology reviewed periodically by expert groups and committees.