SAP CS03 — Display Bill of Material
A bill of material, universally shortened to BOM, is the recipe. It says that to make this product you need these components in these quantities. It is one of the two master records production planning is built on; the other is the routing, which says which operations to carry out.
A BOM is not identified by the material alone. It is identified by four things together: the material, the plant, the usage, and the alternative. Usage separates the engineering view from the production view from the costing view, because the same product legitimately has different component lists for different purposes. Alternative separates several valid ways of making the same thing.
BOMs are also date-effective. A BOM you display on today’s date may show different components from the same BOM displayed on a date next quarter, because a change was scheduled through an engineering change number. The valid-from date on the initial screen is not decoration.
The last idea to hold onto is the base quantity. Component quantities are stated relative to it. If the base quantity is 100 and a component quantity is 5, one finished unit needs 0.05, not 5. Misreading this is the classic BOM mistake.
When you would actually use CS03
- Checking which components a product needs before raising a production order.
- Investigating why a production order picked up an unexpected component.
- Confirming a quantity or a unit before a costing run.
- Seeing what a BOM looked like, or will look like, on a particular date.
What the screen looks like
BOM key
Effectivity
| Item | ICt | Component | Description | Quantity | Un | Valid from |
|---|---|---|---|---|---|---|
| 0010 | L | R-2001 | Steel casing, machined | 1.000 | PC | 01.01.2026 |
| 0020 | L | R-2044 | Ball bearing 6204 | 2.000 | PC | 01.01.2026 |
| 0030 | L | R-2110 | Lubricant, food grade | 0.050 | L | 01.01.2026 |
| 0040 | T | Torque to 40 Nm on assembly | 01.01.2026 |
The fields, in plain English
MAST-MATNRThe product the BOM describes — the parent, not the components. A component that is itself manufactured will have its own BOM, which is what makes multi-level explosion possible.
MAST-WERKSThe manufacturing location. The same product made in two plants can have two different BOMs, because the plants may buy different sub-assemblies or use different processes.
Watch out: A BOM that "does not exist" very often exists in a different plant. Check the plant before concluding anything.
MAST-STLANWhich business function the BOM is for. Usage 1 is conventionally production, and other usages cover engineering, costing, plant maintenance and sales. The exact list is configurable, so confirm it in your own system rather than assuming.
Watch out: Usage also controls which item fields are relevant. A component that is not relevant to production will still appear in an engineering BOM and not be consumed by a production order.
MAST-STLALOne of several valid ways to make the same product — a different mix, a different supplier’s component. Which alternative a production order picks depends on the production version and on lot size ranges.
STKO-BMENGThe quantity of the parent product that the component quantities refer to. A base quantity of 100 with a component quantity of 5 means 0.05 per unit. Setting a base quantity above 1 is how small per-unit quantities avoid rounding problems.
Watch out: This is the single most misread figure on a BOM. Read the base quantity before you read any component quantity.
STPO-POSTPWhat kind of line the item is. L is a stock item, consumed from inventory. N is a non-stock item, procured directly for the order. T is a text item carrying instructions and consuming nothing.
Watch out: Text items are counted by people scanning a BOM and reading the row count as a component count. They are not components.
STPO-MENGEHow much of the component is needed per base quantity of the parent, in the component’s own unit of measure.
Step by step
- 1Enter material, plant and BOM usage.
- 2Leave Alternative BOM blank if you are not sure which one you want — SAP will list them.
- 3Set the Valid From date if you need the BOM as at a particular date rather than today.
- 4Read the base quantity in the header before reading any component quantity.
- 5Work down the item overview, noting the item category on each line.
- 6Double-click an item for its detail — validity, scrap, and whether it is relevant to costing.
- 7Use the multi-level explosion transactions when you need the full structure below this level.
Errors you will hit, and what they mean
The BOM does not exist for material R-1001, plant 1000, usage 1
Why: Wrong plant, wrong usage, or the material genuinely has no BOM — which is normal for a purchased part.
Fix: Try the other usages, then the other plants. If nothing exists anywhere, the material is not manufactured and is not supposed to have one.
No valid BOM exists on the key date
Why: The BOM exists but its validity period does not cover the date you entered.
Fix: Change the valid-from date. A BOM created with a future engineering change number will not show on today’s date until that date arrives.
The production order shows different components from the BOM
Why: The order copied the BOM at creation and froze it. The BOM has been changed since.
Fix: This is correct behaviour. Compare against the BOM as at the order’s creation date, and if the order really needs the new components, re-read master data into the order in CO02.
Common questions
What is the difference between CS01, CS02 and CS03?
CS01 creates a BOM, CS02 changes one, CS03 displays one and cannot change anything. CS03 is the right transaction for anyone investigating rather than maintaining, and it is the safer authorisation to hold.
What is the difference between CS03 and the multi-level BOM transactions?
CS03 shows one level: the components directly under this product. The multi-level explosion transactions walk down the whole tree, expanding any component that has a BOM of its own. Use CS03 for a single recipe, multi-level explosion for the full structure of a finished assembly.
Why does the same material have several BOMs?
Two different reasons. Different usages mean different business functions — the engineering list and the production list are not the same document. Different alternatives mean genuinely different ways of building the same product, and which one is used is decided by the production version.
Transactions that go with CS03
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