Northern Ireland Index of Production

The Northern Ireland Index of Production (IOP) is one of the earliest official indicators of the performance of Northern Ireland industry and, as such, represents an important short-term measure of change in a significant area of the economy. The IOP is a quarterly sample survey of around 1,000 companies designed to provide a general measure of changes in the output of the Manufacturing, Electricity, Gas, Water and Mining & Quarrying industries. It is based on up-to-date information about the output and sales of the production industry. The Index is published in March, June, September and December of each year.