Overview of Structures

Structures, also known as Bills of Material (BOM), are used to store lists of items that are associated with a parent item and information about how each item is related to its parent.

Supported structures are standard, model, option class, and planning. The type of structure that you can define for an item depends on the value specified against the item's item structure type attribute.

Primary and Alternate Structures

A primary structure is a list of the components you most frequently use to build a product. A structure, other than primary, is another list of components for the same basic assembly.

The primary structure is the default for rolling up costs, defining a job, and calculating cumulative item lead times.

Scheduling programs use the primary structure to plan materials. Order management programs use the primary structure for model and option class products to list available options.

When you build an item, roll up costs, and perform other functions that use structures, you can specify whether to use the primary structure (the default) or an alternate structure. You can also use change orders to control changes to primary and other structures.

Use alternate structures to account for manufacturing variations that produce the same assembly, by specifying the parent item number and an alternate name when you create a structure.

You can use an alternate to define an engineering structure or routing. The alternate is used as a prototype variation from the primary manufacturing structure that produces essentially the same assembly.

Common Structures

Common structures are referenced structures that share a component hierarchy, including the substitute components and reference designators defined for the components.