Ancillary activities are undertaken to support principal and secondary productive activities of a unit by providing goods or services entirely or primarily for the use of that entity, such as bookkeeping, transportation, storage, purchasing, sales promotion, cleaning, repair and maintenance, security etc. The output is always intended for intermediate consumption within the same unit and is therefore usually not recorded separately. Although most ancillary activities produce services, some goods-producing activities may, by exception, be regarded as ancillary. The goods thus produced, however, may not become a physical part of the output of the main productive activities. Ancillary activities are usually fairly small-scale compared with the principal activity they support