Maximize Profits with MKS Inventory and Job Costing Software When did you last run a job costing report? If it’s been awhile because getting accurate data is a challenge, there is an easier way. Inventory is one of the biggest operating costs you’ll face, so you better get it right. If you don’t know the answer to some basic business questions, don’t expect accurate job costing: How can I account for missing/stolen inventory? How much on-hand inventory do you have? How much do you need to order? How much of each part is on the trucks? How much of your investment is sitting on the warehouse shelves?