Redefinitions, one of the three methods for handling secondary products, are made as part of the preparation of the supplementary I-O make and use tables. Redefinitions are made when an industry's production of a secondary product requires very different inputs than those for the production of its primary product. In such a case, the economic activity (employment, value added, and output) associated with the secondary product is moved (i.e., redefined) from the industry in which the output occurs to the industry in which the product is primary. For example, any construction work performed by employees of non-construction sectors is shifted from the non-construction sectors to the appropriate construction sector. This same process is used for several other types of activities as well, such as the transfer of food service activity from the lodging and other sectors to the food services and drinking places sector. Redefinitions do not affect the definition of the commodity or the measurement of commodity output, which consists of all of the output of that commodity wherever it is produced. However, redefinitions do affect industry output.