How to Set Up a Job Costing System for Manufacturers

If you finish a job and can't say what it cost, you're quoting the next one on a guess. A job costing system fixes that. It doesn't have to be expensive, but it does have to be set up in the right order.

This is the setup guide: what to decide first, how to configure the books, how to build the overhead rate, and what the monthly routine looks like. I've included an illustrative job cost sheet and overhead rate with the math worked out.

What is job costing, and why does it matter for manufacturers?

Job costing means collecting every cost of a specific order in one place: material, labor, outside work and a share of overhead. When the job closes, you compare that cost to what you charged.

The P&L tells you whether the company made money. It doesn't tell you which jobs made it and which ones gave it back. Two jobs with the same price can have very different costs, and a blended margin hides that.

For a shop that quotes custom work, job costing is also how quoting gets better. Every closed job is a data point for the next quote. Without it, the estimator is working from memory.

What are the cost components every job costing system must track?

Four buckets. Most textbooks say three, but I'd split outside processing out because it's so easy to lose.

• Direct material. What actually went into the job, at actual cost. Not what was ordered, and not the estimate.
• Direct labor. Hours worked on the job, at the loaded labor rate (wage plus payroll taxes and benefits).
• Outside processing. Plating, heat treat, coating, testing and any other work you send out for that job.
• Applied overhead. A share of everything else it takes to run the shop: supervision, depreciation, maintenance, utilities, rent, quality, shop supplies.

The first three are traced. You know exactly which job they belong to. Overhead is applied, using a rate. Getting that rate right is most of the work, and there's a full walkthrough in calculating labor and overhead cost.

Should you use job order costing or process costing?

If each order has its own specs, quote and run time, use job order costing. That covers most machine shops, fabricators, finishers and build-to-print contract manufacturers.

If you run the same product continuously and every unit is the same, process costing is simpler and fits better. Some shops do both. The full comparison, with an example of each, is in job costing vs. process costing for manufacturers.

The rest of this guide assumes job order costing.

Step 1: Decide what counts as a job

Usually one job equals one customer order line, or one work order. Pick a rule and stick to it.

The rule matters because you'll be comparing jobs over time. If one blanket order is a single job this year and twelve releases next year, the history won't line up. For a blanket order, I'd usually make each release its own job and tie them together with the customer PO.

Every job gets a number before any cost is incurred. That number goes on the traveler, the time entries, the purchase orders and the vendor bills.

Step 2: Set up the chart of accounts and the software

You need a few balance sheet accounts that small shops often don't have:

• Raw materials inventory.
• Work in process (WIP): cost sitting on open jobs.
• Finished goods, if you build ahead of shipping.
• Applied overhead, a contra account that holds overhead charged to jobs until month-end.

Then the software has to tag each cost to a job. In QuickBooks that's customer:job or class tracking, usually with an add-on for inventory and work orders. Fishbowl and NetSuite have manufacturing modules that handle work orders, issues and labor directly. Which one fits depends on your volume and how many people touch the data. We compare them in QuickBooks vs NetSuite vs Fishbowl.

I'd rather have a simple system that everyone uses than a powerful one half the floor ignores. Either way, the setup questions below are the same.

Step 3: Build the BOM and routing for repeat work

For parts you make more than once, set up a bill of materials (what goes in) and a routing (which operations, on which work center, for how long).

These become your estimate. When the job runs, actual material and hours are compared against them. For one-off jobs, the quote plays the same role.

Keep the routing honest. If the routing says 20 minutes a part and the floor knows it takes 28, the variance report will flag every job and people will stop reading it.

Step 4: Calculate a predetermined overhead rate

You can't wait until year-end to know overhead per job. So you set a rate in advance: budgeted overhead divided by a budgeted activity measure, usually direct labor hours or machine hours.

Illustrative example. A shop budgets $1,080,000 of manufacturing overhead for the year and expects 24,000 direct labor hours.

$1,080,000 / 24,000 hours = $45 of overhead per direct labor hour.

Pick the base that drives your costs. If people drive the cost, use labor hours. If machines do, and one operator runs several, machine hours are better. Some shops use a separate rate per work center. The combined labor and overhead figure per hour is what many people call the shop rate.

Use the hours you expect in a normal year, not every hour you could possibly run. If you base the rate on full capacity, it comes out too low and every job looks better than it is.

Step 5: Capture material by job

Material reaches a job two ways. Job-specific purchases go straight to the job on the PO. Stock material gets issued from inventory to the job when it's pulled.

The weak spot is informal pulls. If someone grabs bar stock off the rack and nobody records it, the job is short and inventory is wrong. A pick ticket or a scan at the rack fixes this. It's a process change more than a software one.

Also decide how freight in, cutting charges and job-specific tooling get coded. My preference is to put them on the job whenever they belong to one.

Step 6: Capture labor by job

Labor needs hours by person, by job, and ideally by operation. Clock-in at the job level on a tablet or terminal works best. A paper traveler with start and stop times works if someone enters it daily.

Track setup separately from run time. It's the first thing estimators get wrong and you can't fix what you don't measure.

Cost the hours at the loaded rate: wage plus employer payroll taxes, workers' comp and benefits. Our post on the fully loaded cost of a manufacturing employee shows how to build it.

One more thing. Total hours charged to jobs plus indirect hours should equal total hours paid. If they don't tie, hours are leaking somewhere.

Step 7: Build the job cost sheet

The job cost sheet is where it all comes together. Estimate in one column, actual in the next, difference in the third.

Here's an illustrative job priced at $7,800. Labor is costed at a $34 loaded rate and overhead at the $45 rate from Step 4.

Cost line	Detail	Actual
Direct material	Issued to the job	$2,350
Direct labor	42 hours at $34	$1,428
Applied overhead	42 hours at $45	$1,890
Outside processing	Heat treat	$300
Total job cost		$5,968
Gross profit	$7,800 less $5,968	$1,832 (23.5%)

Put the estimate next to each line and you can see right away where a job went off. That comparison is the whole point. How to read it is covered in when job costs go over budget.

Step 8: Close the month and true up overhead

At month-end, two things need to happen.

First, WIP has to tie. The total of all open job balances should equal the WIP account on the balance sheet. If it doesn't, something was posted without a job, or a closed job didn't get relieved. Chase it down before you report.

Second, compare overhead you applied to jobs with what you actually spent. Illustrative example: the shop above logged 1,850 direct labor hours in March, so it applied 1,850 x $45 = $83,250. Actual overhead for March was $93,000. That's $9,750 underapplied.

Small differences can go to cost of goods sold. If it's underapplied month after month, the rate is too low or volume is below plan. Either way, the jobs you quoted were costed too cheap. That's a pricing question, not just an accounting entry.

Our month-end close checklist for job shops lists these steps in order.

Step 9: Close out each job and review it

When a job ships, close it within a week or so. Late vendor bills will still trickle in, so set a cutoff and accrue anything known but not billed.

Then look at estimate against actual. Where was it off, and why? Write one line in a log. After a few months that log is the best estimating tool you have. The next post in this series, how to use job cost reports to sharpen bidding accuracy, picks up from there.

What mistakes should you avoid when setting it up?

• Costing labor at the bare wage. Use the loaded rate or every job is understated.
• No overhead on jobs. Material plus labor is not the cost of a job.
• Posting the estimate as the actual. Some systems backflush the standard and never record real usage. Then you never see variances.
• Letting WIP drift. If open jobs don't tie to the balance sheet, nobody trusts the reports.
• Too much detail on day one. Twenty labor codes nobody uses are worse than four that everyone does.

More of these are covered in hidden job costing mistakes manufacturing owners make.

Who owns each part of the system?

Job costing breaks down when everyone assumes someone else is checking. I'd write down an owner for each piece, even in a small shop.

Piece	Usual owner	What they check
Job numbers and travelers	Scheduler or production manager	Every order has a job before work starts
Time entry	Shop lead	Hours are entered daily and charged to the right job
Material issues and POs	Purchasing or inventory lead	Job-specific buys carry a job number; pulls are recorded
Vendor bills	AP	No bill for job material or outside work is entered without a job
Rates, WIP tie-out and close	Controller or outside accounting team	Overhead rate, applied vs actual, WIP ties to the balance sheet
Job review	Owner, estimator and shop lead together	Estimate vs actual on closed jobs, and what changes in the next quote

The last row matters most. If the estimator never sees the closed job, the system is just recordkeeping. A 30-minute review each month with the three people who quote, run and pay for the work is usually enough.

If you don't have a controller, this is the piece that tends to slip. Someone needs to own the rates and the tie-out every month, not just at year-end.

How long does it take to set up?

It depends on where you start. If the software already supports jobs, the accounting side can be set up in a few weeks. The floor habits, timekeeping and material issues, take longer.

I'd plan on running it in parallel for a couple of months and fixing what breaks. The first month's job costs will be rough. That's normal. By the third month you should be able to trust the numbers on most jobs.

How we help

We set up and run job costing as part of our manufacturing accounting and outsourced controller work: the chart of accounts, overhead rates, WIP tie-out and the monthly job review. Once the numbers are solid, our pricing and margin analysis uses them to look at margin by job type and customer.

We work most often with CNC and precision machining and metal fabrication shops. If you want help getting job costing set up, happy to jump on a call.

Frequently Asked Questions

What software do I need for job costing?

You can start in QuickBooks with job or class tracking. As volume grows, a manufacturing system like Fishbowl or an ERP like NetSuite handles work orders, material issues and labor better, but the setup steps are the same.

Should overhead be applied by labor hours or machine hours?

Use whichever drives your costs. If one operator runs several machines, machine hours usually give a truer cost; if the work is people-heavy, labor hours are fine.

What is underapplied overhead?

It's actual overhead that is higher than what you charged to jobs through the rate. If it keeps happening, your rate is too low and your jobs have been costed too cheap.

Can I use job costing if I also run repeat production?

Yes. Use BOMs and routings for repeat parts so each work order is compared to a standard, and use the quote as the budget for one-off jobs.

How often should I review job costs?

Review each job when it closes and look at the whole month at month-end. Big open jobs deserve a weekly look so you can act before they finish.