SAP Routing

A routing lists the operations to produce a material in order, each assigned to a work center (where it happens) with standard times (setup, machine, labour). It is the process counterpart to the BOM’s materials, and drives scheduling, capacity and costing.

• Operations & sequence: the manufacturing steps.
• Work centers: where each operation runs.
• Standard times: for scheduling and costing.
• Components assignment (which BOM items are used at which operation).

CA01 creates a routing, CA02 changes it and CA03 displays it. The work centres it points at are maintained with CR01, and CR05 lists which routings use a given work centre, which is the report to run before changing one.

A routing is a group of operations against a material and plant. Each operation names a work centre, a control key that says what the operation does, and standard values: setup time, machine time and labour time. Those values are not decoration. They drive scheduling, they drive capacity, and through activity rates they drive cost.

The tables are PLKO for the routing header, PLPO for its operations and PLAS for the sequence that links them. MAPL connects a routing to the materials that use it, which is why one routing can serve several similar products.

Half an hour, and it demonstrates why routing accuracy is not a detail.

1. Display a routing with CA03 and note the standard values on one operation.
2. Create a production order for that material with CO01. Look at the scheduled start and finish dates, and at the operations copied from the routing.
3. Run a cost estimate for the material, or read the planned costs on the order. Labour and machine cost came from those standard values multiplied by the work centre's activity rates.
4. Now change the machine time on that operation with CA02 and create a second order. The dates move, the capacity requirement moves, and the planned cost moves.
5. Confirm the first order with a very different actual time in CO11N. The variance that appears is the gap between what the routing promised and what happened.

One field, three consequences. That is the argument for keeping routings current, and it is also why an out of date routing quietly distorts both the schedule and the product cost.

The routing drives production scheduling (using operation times and work-center capacity), capacity planning, and the labour/machine cost in product costing. With the BOM, it forms the basis of the production order. Inaccurate routings cause bad scheduling and wrong costs.

It also decides what the shop floor is asked to do. Operations become the confirmation steps operators see, so a routing with ten operations produces ten confirmations and a routing with two produces two. That is a real trade-off between visibility and the effort of recording it. See SAP PP for where routings sit in the wider module.

• How finely to break up operations. More operations give better scheduling and costing detail and more confirmations to enter. Fewer are easier to run and blunter to report on.
• Where standard values come from. Time studies are accurate and expensive. Estimates are quick and drift. Whichever you choose, somebody has to own reviewing them.
• Reference operation sets or standalone routings. Shared sets keep common sequences in one place and mean a change reaches everything that uses them, which is the point and also the risk.
• Which control keys. They decide whether an operation is scheduled, costed, confirmed and printed, and a wrong one produces an operation that quietly does nothing.

A routing is only as meaningful as the work centres it points at, and those carry the data that turns times into schedules and money.

A work centre is where an operation happens: a machine, a line, a team. It holds the formulas that convert the routing's standard values into scheduled duration and into cost, the capacity available per day, and the cost centre and activity types that price the time.

Capacity is the part most often left at defaults and then quietly ignored. Available capacity is defined per day, and scheduling can either respect it or not depending on how the order type is configured. A plant that schedules infinitely will happily plan three days of work into one, and the shop floor discovers it rather than the planner.

Activity types connect production to controlling. Machine time and labour time are priced at rates held against the cost centre, so the cost of an operation is standard value times rate. If the rate is stale, every product cost using that work centre is wrong by the same proportion, and nothing in PP will flag it.

Formulas decide how the standard values are used. A setup time that should be charged once per order and is instead charged per unit produces costs that scale absurdly with order size, and that specific error is common enough to be worth checking first when a cost looks wrong.

Changing a work centre affects every routing that uses it, so the where-used list comes before the change. See SAP PP configuration for the order types and scheduling settings that decide how all of this is applied, and production orders for what consumes it.

Two variations worth knowing, because they solve problems a plain routing does not.

A reference operation set is a sequence of operations maintained once and referenced by many routings. Where a dozen products share the same finishing steps, the steps live in one place, and a change to them reaches everything that references them. That is the benefit and the risk in one sentence, so the where-used list matters more here than anywhere else.

A rate routing is used in repetitive manufacturing, where production runs continuously rather than in discrete orders. Instead of times per operation it carries a production rate, quantity per unit of time, which is how a line producing thousands of units an hour is modelled sensibly.

Reference rate routings combine the two ideas for the same reason.

Choosing between them follows the plant rather than preference. Discrete assembly with distinct orders takes ordinary routings. A line running a product continuously takes a rate routing, and forcing one into the other produces schedules nobody trusts.

• Inaccurate times, bad scheduling/costing.
• Wrong work-center assignment.
• Components not assigned to operations.

• Changing a routing without checking what uses it. Run CR05 or the where-used list first.
• Standard values copied from an old machine. The schedule then promises dates the plant cannot meet, and nobody suspects the routing.
• Forgetting the validity date. Routings are date-effective, so a change applies from a date, and orders created before it keep the old operations.

• Assuming the routing is right because production is running. A plant can run perfectly well against wrong standard values; the symptom is a schedule nobody believes and a product cost finance queries, not a stopped line.

Reading a routing is straightforward, and setting standard values, control keys and work centre rates so scheduling and costing both come out right is the part you do in the course.

The check worth doing on any routing you inherit is whether the standard values were ever reviewed. They drive the schedule and the cost, they are usually set once at go-live, and a plant that has changed its machines since then is being planned against times that no longer exist.