What Is a Routing in Manufacturing? Job Shop Examples

Most explanations of routing in manufacturing come from ERP vendors and use a generic assembly: cut, assemble, test, ship. That is fine for a definition, but it does not help an estimator or planner in a fab shop or machine shop write one. This post defines a routing, then walks through two job-shop routings with real work centers, setup and run times, and shows how each one becomes a cost at 10 and at 100 pieces.

What is a routing in manufacturing?

A routing is the ordered list of operations needed to make a part, giving for each operation the work center, the setup time and the run time per part. It is also called a process routing, a router or an operation sequence. In a job shop, the routing is the bridge between the drawing and the price: it says how the part will be made, and the times on it are what you multiply by your rates.

A typical routing line holds:

• Operation number: usually in steps of 10 (10, 20, 30) so operations can be inserted later.
• Operation description: laser cut, press brake, mill op 1, anodize.
• Work center: the machine or cell, or the outside vendor for subcontracted steps.
• Setup time: time to get the work center ready for this job, charged once per order or batch.
• Run time: time per part once the setup is done.
• Notes: tooling, program number, bend count, inspection points, hardware.

What is the difference between a routing and a bill of materials?

The bill of materials (BOM) lists what goes into a product; the routing lists the work done to make it. You need both to cost a part: the BOM gives material and purchased-part cost, the routing gives labor, machine and outside-processing cost.

What does a sheet metal routing look like? Bracket example

The part: a 14 ga (0.075 in, 1.9 mm) mild steel mounting bracket with four bends and four PEM nuts, powder coated black. The work-center rates and times below are example figures; use your own. Setup and run costs are simply time multiplied by the work-center rate.

The press brake setup reflects the bend count: four bends with one tool setup and a test bend. A part with eight bends across two tool stations would carry more setup and more run time, which is why counting bends from the drawing matters (see our guide on bend counting from 2D drawings). Powder coat is an outside process, so it is costed from the vendor's price, $4.00 per part with a $150 lot minimum, not from your shop rate.

Bracket cost at 10 vs 100 pieces

Routing cost per part = (Total setup cost / Quantity) + Run cost per part + Outside processing per part
Total cost per part = Routing cost per part + Material per part (from the BOM)

At 10 pieces, setup and the powder coat minimum make up $27.00 of the $39.40, about 69%. At 100 pieces they are $5.20 of $17.60, under 30%. Run cost does not change at all. That is the whole story of quantity breaks, and it comes straight from the routing.

What does a CNC machining routing look like? Machined part example

The part: a 6061-T6 aluminum housing, about 3 x 2 x 1 in (76 x 51 x 25 mm), machined on two sides on a vertical machining center, black Type II anodize. Again, example figures; use your own.

The machined part behaves differently from the bracket. Run time is much larger (21.5 minutes against 5.1), so even at 100 pieces run cost is three quarters of the price. For machined parts, cutting cycle time with better toolpaths or more parts per fixture moves the price more than setup does. For short-run sheet metal, setup reduction matters most. The routing tells you which lever to pull.

How do you write a routing for a new part?

You can write a routing from a 2D drawing in a few minutes once you have a method. Work through the drawing in the order the part will physically move through the shop:

1. 1

   Start from the raw material

   Read material, gauge or stock size from the title block and pick the first operation that creates the blank: laser, punch, shear or saw.

2. 2

   Add forming or machining

   Count bends, flanges and tool changes for sheet metal; count setups (sides or faces) and features for machined parts. Each setup on a machine is usually its own operation.

3. 3

   Add secondary operations

   Scan the notes and views for deburr, countersinks, tapped holes, hardware callouts, welds and grinding. These are the lines most often missed.

4. 4

   Add outside processes

   Finish, plating, heat treat and passivation go in sequence where they happen, with the vendor as the work center and their lot minimum noted.

5. 5

   Close with inspection and pack

   Include first article and final inspection, plus any certification paperwork, then packing.

6. 6

   Set the times

   Apply your standard setup and run rules per work center, then sanity-check against a similar part you have already run.

How do routings drive quoting?

Every labor dollar on a quote should trace to a routing line: a work center, a time and a rate. When a quote looks wrong, the routing is where you check it. Missing an operation (deburr, hardware, masking) is the most common reason a job loses money, and an inflated setup on a high-volume part is a common reason a quote loses. Accurate rates per work center matter as much as the times; our shop rate calculator shows how to build them, and the job shop quoting process shows where routing sits in the full RFQ-to-quote flow.

Consistency is the other half. If one estimator routes a bracket with a 30-minute brake setup and another uses 15, the shop sends different prices for the same work. A process library, a shared list of operations with standard setup and run rules per work center, keeps routings consistent. This is also what AI quoting tools build on: Customiser routes each part through the shop's own processes and costs it with the shop's own labor standards and rate cards, showing the working for every line so the estimator can check and approve it.

How do routings drive scheduling and capacity planning?

Once a job is won, the same routing becomes the traveler on the shop floor and the input to the schedule. Each operation's setup plus run time, times quantity, is the load on that work center. For the 100-piece bracket order, the in-house load is 70 minutes of setup plus 5.1 minutes x 100 parts = 510 minutes of run, about 9.7 hours in total, of which 2.5 hours sit on the press brake (30 minutes setup plus 120 minutes run).

• Scheduling: operation order sets the sequence, and outside processes add vendor lead time between ops.
• Capacity: summing routing hours by work center across open orders shows where the bottleneck is this week.
• Lead time: quoting a lead time without checking routing load on the bottleneck work center is guessing.
• Job costing: comparing actual hours against routing hours after the job tells you whether your standards are right.

What are common routing mistakes?

• Leaving out small operations: deburr, masking, hardware insertion, tapping and cleaning are easy to forget and add up.
• One blended rate: a laser hour and a bench hour do not cost the same. Rate each work center separately.
• Setup charged per part: setup belongs once per order or batch, then divided by quantity, not multiplied by it.
• Ignoring lot minimums: outside processes like plating, anodize, powder coat and heat treat often have minimum charges that dominate small orders.
• Not updating from actuals: if the brake setup is always 45 minutes, a 30-minute standard will keep losing you money.
• Routing to the wrong revision: an added bend or a new finish on Rev D changes the routing, so tie each routing to a revision.

If you want to see routings built from your drawings with your own processes and rates, and every line linked back to the drawing, see how Customiser works.