Working with Material BOMs in the Design Phase

If you manufacture your forklift at some point, you need a list of the components to be produced in addition to the work instructions. To do this, you now use a material BOM.

A bill of material (BOM) is a complete, formally structured list of the components that make up a product or assembly. The list contains a description and object number for each component, together with the quantity and unit of measure.

The BOM contains essential basic data, or master data, for integrated materials management and shop floor control. A BOM describes which components are needed to construct an assembly. A BOM always contains one level (single level) in the SAP system. Only if extra BOMs are created for its components does a BOM become multilevel.

BOMs are used in their various forms wherever finished products or semifinished products are assembled from various components or substances. Depending on the industry sector in which they are used, they are also known as recipes or lists of ingredients.

Material BOMs usually show the structure of products that are manufactured in a company. Product descriptions can consist of programs, technical drawings, documents, or photographs. The related document info records are collected in document structures.

Equipment BOMs are used to describe engineering structures for equipment, or to assign spare parts to equipment for maintenance purposes. BOMs for functional locations group together the elements of a technical structure, such as the functional unit of a plant.

If you want to control the use of the material BOM in Logistics, you need the appropriate usage.

The wide range of BOM data that you must enter is managed in a structured manner. Here, we differentiate between data that is valid for the entire BOM and data that applies to the individual BOM items only.

Data for the entire BOM is stored in the BOM header. It can be the BOM status, the BOM text, or general administrative data.

The general data for the BOM item is stored in the item detail screen. It can be general administrative data, or the item status for controlling the use of the individual items.

When you enter new BOM items, you must assign an item category to each item. The item category defines the properties and functions of an item. It specifies which item data is processed and controls subsequent system activities.

The item category answers the following questions:

• Is a material number required?
• Is quantity-based inventory management supported for the item?
• Can there be negative quantities of the item?
• Are subitems supported?
• Which screens are selected and which fields appear on the item detail screens?
• Is it a preliminary or a reference item?

Only working with a preliminary item, you are able to change the item category. In all other cases, you have to delete the item and enter a new one with the right item category.

For example, if you want to include a document in a BOM, choose item category D. Then, enter a document info record that was created in document management. The originals can be displayed directly from the BOM.

The BOM status controls the entire BOM in the various downstream application areas. For example, the status allows or forbids the use of the BOM in MRP.

The item status controls how the individual BOM items are used inside the logistic chain.

For example, one item might be relevant to engineering only, whereas another is relevant to engineering and production. When creating a production order, only these components show a production relevant indicator, are copied inside the material BOM.

In general, BOM usage is just information on how the item status can be defined. Only the item status defined for every component is relevant inside the logistic chain.

BOM Engineer Marc has now the task to create a component list for the new forklift prototype. As no plant specific data are available, he decide to create a group BOM based on a template.

He works with the BOM, he checks the individual components and header status. He also adds a document.

At the end Development Manager Thomas checks and adopts the data inside Engineering Control Center (ECTR).

BOM Engineer Marc creates a group BOM for the new forklift prototype. He uses a template BOM and checks component and header status.

BOM Engineer Marc processes the new created group BOM. He add documents and adjusts the BOM layout for different purposes. He explores different components and item categories.

As the header material is still available inside ECTR, Development Manager Thomas checks and updates the material BOM. At the end he searches for newly created materials and adds them to the design phase.

Now you should have an impression of "Working with material BOMs in design phase" could look like.