Stocks of work in progress refers to the value of all materials that have been partially processed by the establishment but that are not usually sold, shipped or turned over to other establishments without further processing. Generally, it should include all work in progress for the account of others, irrespective of the arrangements for financing the work. However, that part of the work in progress on long-term contracts for which progress payments have been included under shipments should be excluded. Work in progress on own-account production of machinery and equipment should be included, but partially completed construction work should be excluded. The latter should be treated as part of fixed capital formation.