Creating BOMs

The Bike Company is currently focused on producing a single bicycle model. This model requires specific quantities of each component. For example, it needs two wheels, two pedals, and one frame. The components should be assembled in a specific sequence and at specific steps in the production process.

In SAP Digital Manufacturing, a Bill of Materials (BOM) is a structured list that includes all the components and their quantities necessary for an assembly. For example, a BOM specifies the quantities of subassemblies, materials, raw materials, and intermediates needed to create a parent assembly. The BOM is divided into two levels: the header, which represents the semifinished or finished material to be produced, and the item level, which includes the components required to assemble the header material.

Bills of Materials are maintained in the Manage Bill of Materials application. The BOM type identifies the source of the BOM for an object. The following BOM types are supported:

• Master: This is the default BOM for an object.
• Order: Is usually created when specific BOMs are required for different production orders, for example during a prototyping phase.
• SFC: If a certain Shop Floor Control (SFC) requires the assembly of specific components that differ from the master or order BOMs.

When trying to identify which BOM to use, the SFC's BOM takes precedence over the order BOM. The order BOM takes precedence over the master BOM.

Each BOM when defined can have one of the following statuses:

• New: This BOM record is new and not ready for production. You cannot use this BOM to release SFCs, but you can change this BOM record.
• Releasable: You can use this BOM when releasing SFCs.
• Obsolete: This BOM is no longer used. You cannot use this BOM to release SFCs.
• Hold: This status is temporary. You cannot use this BOM to release SFCs. Once the hold issue has been resolved, you should change the status of this record.

In SAP Digital Manufacturing, BOMs can exist in several versions. If the current version of the BOM is changed at any time, the dependency between the BOM, material, and routing also changes. The change of the current version can affect the assembly process. 

At the component level of a Bill of Materials (BOM), you maintain the individual components, their assembly sequence, assembly quantity, and assembly operation. The item quantity represents the quantity in which this component will be assembled. For example, the bike consists of one frame, two wheels, and two pedals.

It is possible to add other settings for each BOM component.

During assembly, the system can enforce the recording of more data, such as the serial number of the used component. If this information is required for traceability purposes, the assembly data type must be specified. Note that it is also possible to define this setting on the material level. If a respective setting is available on the material and on the BOM component level, the BOM component setting takes precedence and overrides the settings on the material level.

Usually, the BOM component corresponds to the component that will be assembled. However, it is possible that this component is not available, for example, in the case the supplier cannot deliver the component. If so, it is possible to specify alternate components that can be used as a substitute. Similar to the previous setting, BOM component level settings take precedence over the settings on the material level.

Sometimes, the required component quantity cannot be preplanned (for example, lube, paint, and so on) and therefore the component quantity can differ from the BOM component quantity. For these components, the Assembly Quantity as Required flag can be set. If set, the production operator enters the consumed quantity of the respective component in the operation Production Operator Dashboard (POD). Components bearing this indicator have no value in the Assembly Quantity field in the POD.