In job order costing,  the Work  in  Process  Inventory  control  and  subsidiary ledger accounts  for Ecoland Marine’s product costing system. The usual production costs of direct material, direct labor, and overhead are accumulated for each contract. 
Actual direct material and direct labor costs are combined with an overhead cost that is computed as a predetermined overhead rate multiplied by some actual cost driver (such as direct labor hours, cost or quantity of materials used, or number of material  requisitions). 
Normal cost valuation  is used because, although actual direct material and direct  labor costs are  fairly easy  to  identify and associate with a particular job, overhead costs are usually not traceable to specific jobs and must be allocated  to production. 
For example, Ecoland Marine’s March utility costs are related to all jobs worked on during that month. Accurately determining which jobs created  the need  for a given amount of water, heat, or electricity would be almost  impossible.
To ensure the proper recording of costs, the amounts appearing in the subsidiary ledger accounts are periodically compared with and reconciled to the Work in Process Inventory control account in the general ledger. This reconciliation is indicated by the equality of the assumed ending balances of the subsidiary ledger accounts with the WIP Inventory control account.
To ensure the proper recording of costs, the amounts appearing in the subsidiary ledger accounts are periodically compared with and reconciled to the Work in Process Inventory control account in the general ledger. This reconciliation is indicated by the equality of the assumed ending balances of the subsidiary ledger accounts with the WIP Inventory control account.


