Job Shop Quoting

Job Costing in Manufacturing: A Practical Guide

Job costing tracks actual material, labor, and overhead to each specific job. Here is how to build a job cost system, apply overhead correctly, and use variances to control cost.

Job costing assigns actual cost to a specific work order or production lot. Job cost equals direct material plus direct labor plus applied overhead. Applied overhead is usually actual direct labor hours on the job x predetermined overhead rate. For a job with $840 material, 12 hours of direct labor at $28 per hour, and an overhead rate of $42 per direct labor hour, total job cost is $1,680. If the job ships 120 parts, cost per part is $14.00, which is the number you compare to the quoted sell price.

Direct material includes raw stock, purchased components, and consumables that can be clearly traced to the job. Direct labor requires accurate time reporting against the job number at each operation. Overhead is applied using the plant's chosen base, often direct labor hours or machine hours. Material prices should come from actual purchase cost for the lot where possible, not just from outdated standard cost. The job cost sheet should also capture outside processing, freight-in, and special tooling if they are unique to the order.

The biggest job costing mistake is weak labor reporting. If operators guess their hours at the end of the week instead of clocking in and out by job, labor variance becomes noise. Another common miss is treating indirect material or shop supplies as direct job cost for one order and overhead for another. Plants also fail to separate material price variance from material usage variance, so they cannot tell whether the cost overrun came from purchasing or from production. Bad coding discipline turns the job cost system into a spreadsheet exercise instead of a control tool.

Use job cost data to compare actual job performance against the estimate and to find where money was lost. Job variance equals standard or quoted job cost minus actual job cost. Break the variance into material quantity, material price, labor efficiency, and overhead to see which function owns the problem. This makes the data actionable for purchasing, production, and estimating. It also helps account managers explain why one customer or part family is consistently weak.

The real value of job costing is feedback into future quotes. If actual cost is consistently 15% above estimate on a part family, the standard routing, burden rate, or material assumption needs revision. Use 6 to 12 months of history to recalibrate standards and refine future pricing. Related metrics such as shop rate, RFQ hit rate, and gross margin by job family help show whether the estimating process is improving. Good job costing closes the loop between what the shop promised and what the shop actually spent.

Published 2026-05-28.