Modular BOM

Modular Bill of Material (BOM) is a critical element in defining the product structure of an end-item.

Modular BOMs define the component materials, documents, parts and engineering drawings needed to complete a sub-assembly. While the term BOM and Modular BOM are most commonly used in association with physical products, the concept can be used in a variety of industries (software, medical records, etc.) Modular BOMs are used by modern information systems to serve a variety of purporses, they define the components needed to produce a subassembly, they provide cost information for each component and "rolled-up" cost for the overall subassembly,

For option-based, configurable products (think automobiles, PC's, etc.) companies needed to plan every combination and permutation of options to ensure they could fulfill customer demands. With a modular BOM structure, companies can plan the demand for each module independent of the end-item demand by estimating the popularity of the module sub-assembly.

Multi-Level BOM Explosion

Purpose

The setting BOM explosion: multi-level means that multiple levels of the BOM of a configurable material are exploded in the sales order, if the configuration profiles of the configurable assemblies also support BOM explosion. You can configure assemblies across multiple levels.

Variant product MULTIMEDIA_WORKSTATION supports multi-level BOM explosion. The BOM contains configurable material PC. This material supports single-level BOM explosion. The BOM of the PC contains another configurable material MONITOR.

Features

• All configurable items are configured in the sales order, not only sales-relevant items.

You can use filters in the configuration profile to restrict the scope of the BOM items (see Filters for BOM Explosion).

• Sales-relevant items are copied to the sales order as order items.

• The characteristic values assigned to each configured item are saved.

• In MRP, components and operations selected depend on the characteristic values assigned according to the principles of low-level configuration (see
Low-Level Configuration).

• If you define selection conditions for the BOM items of a subordinate configurable assembly, and these selection conditions refer to the characteristics of the assembly, you must use the object variable $PARENT to refer to the characteristics.

The selection conditions for BOM components of the PC must refer to the characteristics of the monitor with object variable $PARENT – for example, $PARENT.MANUFACTURER = 'Sony'.

• This type of order processing lets you use constraints to infer values for configurable materials on different levels.

Prerequisites

The configuration profile of the header material has the configuration parameter BOM explosion: multi-level.

The subordinate materials whose BOMs are to be exploded in the sales order must also have a BOM explosion parameter (single-level or, preferably, multi-level).

Process Flow

1. Create a sales order and enter the configurable material as an order item.
2. You see the configuration editor, where you assign values to the characteristics of the header material. You can then display the result of the BOM explosion by choosing Result.
3. If any of the selected BOM components are also configurable materials, you can assign values to the characteristics of these materials. Depending on the configuration parameters, the BOMs of these materials are exploded on the result screen.
4. The header material appears as a sales order item. If the BOM contains further sales-relevant items, these are included as sub-items. The characteristic values assigned to the header material and the subordinate configurable materials are saved.
5. In the planned order or production order, BOM components and operations for the configured materials are determined according to the characteristic values assigned.

Single-Level BOM Explosion

Purpose

The BOM is exploded on one level on the result screen in the sales order. Other configurable material can be contained in the BOM and these can be configured. However, the BOMs of these materials are not exploded in the sales order.

You can combine this setting with Process: Sales order when dealing with configurable material of the BOM that you want to assemble in a set structure.

See also: Process: Sales Order

Example

The materials PC and MONITOR are configurable. The monitor has its own configuration profile and characteristics. The configurable PC has the setting BOM explosion: single level in its configuration profile. On the result screen in the sales order, you see the selected components.

Configurable material MONITOR can also be configured in the sales order. However, the BOM of the PC is not exploded, because a single-level explosion only is defined for the header material. The configuration parameters for the material MONITOR are not important in this instance.

Features

• All configurable items are configured in the sales order, not only sales-relevant items. The BOMs of these materials are not exploded in the sales order.

You can use filters in the configuration profile to restrict the scope of the BOM items (see Filters for BOM Explosion).

• Sales-relevant items are copied to the sales order as order items.

• The characteristic values assigned to each configured item are saved.

• In MRP the required components are determined based on the characteristic value assignments for the head material and the subordinate items as well as the task list operations based on low-level configuration. (See also
Low Level Configuration).

• If you define selection conditions for the BOM items of a subordinate configurable assembly, and these selection conditions refer to the characteristics of the assembly, you must use the object variable $PARENT to refer to the characteristics.

The selection conditions for BOM components of the monitor must refer to the characteristics of the monitor with object variable $PARENT – for example, $PARENT.MANUFACTURER = 'Sony'.

• This type of order processing lets you use constraints to infer values for configurable materials.

Prerequisites

The configuration profile of the header material has the configuration parameter BOM explosion: single level.

Process Flow

1. Create a sales order and enter the configurable material as an order item.
2. You see the configuration editor, where you assign values to the characteristics of the material. You can then display the result of the BOM explosion by choosing Result.
3. If any of the selected BOM components are also configurable materials, you can assign values to the characteristics of these materials. However, the BOMs of these materials are not exploded.
4. The header material appears as a sales order item. If the BOM contains further sales-relevant items, these are included as sub-items. The characteristic values assigned to the header material and the subordinate configurable materials are saved.
5. In the planned order or production order, BOM components and operations for the configured materials are determined according to the characteristic values assigned.

Controlling the BOM Explosion in PP

The following factors determine how a BOM is exploded:

• BOM usage
• BOM application
• Filter defined in the configuration profile

BOM Usage

When you create a BOM, you must enter a usage. This usage defines which application areas (for example, sales and distribution, engineering/design, or production) a BOM can be exploded in. For example, the standard R/3 System supports usage 1 for BOM explosion in production. A BOM with usage 3 is relevant to sales and distribution, too.

The usage determines which indicators are active in the Item status dataset of BOM maintenance functions. This is where you specify whether BOM items are relevant to Sales or Production, for example.

Features

The BOM explosion is influenced by the application entered in the configuration profile. The application determines which usages of a BOM can be exploded and in which order of priority.

You enter the application for exploding the BOM in the configuration profile. However, please note that you can also enter an application for a sales order item category. This entry overwrites the setting in the configuration profile. Check the settings for the item category in Customizing for Sales and Distribution, by choosing Sales ® Sales Documents ® Sales Document Items ® Define item categories.

If you select the Sales order process in the configuration profile, ensure that the application supports explosion of sales-relevant BOMs and that sales-relevant BOMs have the highest priority.

You define an application that explodes first usage 1 and then usage 3. When you explode the BOM, the system first checks whether a BOM with usage 1 exists. If a BOM with usage 1 does exist, the BOM is exploded. If no BOM with usage 1 exists, the system checks whether a BOM of usage 3 exists.

Handling in the Sales Order

• If usage 1 is supported by the application, the BOM for the material is found but cannot be exploded, because usage 1 in the standard R/3 System is not relevant to sales and distribution.

• If usage 1 is not supported by the application, the system does not recognize in the sales order that a BOM exists for the material.

Filters in the Configuration Profile

In the configuration profile, you can define filters so that only certain items are displayed (see Filters for BOM Explosion).

The Configuration Profile

Purpose

You maintain configuration profiles for configurable objects to define central settings for configuring the object.

You can create several configuration profiles with different settings for an object. If an object has several configuration profiles, you must select a profile during configuration. You can only make changes to a configuration with the profile that you first used to configure the object.

Integration

You maintain configuration profiles for all configurable objects:

• Configurable materials
• Configurable standard networks
• Configurable general maintenance task lists
• Configurable model service specifications

Features

You define different settings in configuration profiles for materials than for other configurable objects.

• You use the configuration profile to assign the configurable object to one or more variant classes. This links the object to the characteristics of the class for configuration.

Note that the class is then assigned to the configurable object, not the profile. The profile only allows you to go to classification.

• You can define settings that affect the display options and scope of characteristics on the value assignment screen. You define these settings for each object, and they apply to the object wherever it is used. However, you can overwrite these settings for your user in the configuration editor.

• You can use an interface design to group characteristics together and define a sequence on the value assignment screen. You need to assign a name to an interface design to enable further maintenance in the configuration simulation.

• You can use the configuration profile to assign dependencies to a configurable object. You can only assign dependency nets to a configuration profile. If you assign actions and procedures to the configuration profile, you can manage them more easily because they are all in one place.

• For materials, you must also maintain configuration parameters for BOM explosion. Depending on the configuration parameters you set, other fields in the configuration profile are hidden or shown.
• You determine the status of the configurable object.

You can also define settings for the status in Customizing. In Customizing, choose Configuration Profile ® Configurable Objects ® Material ® Maintain Status.

Defining Classes as BOM Items

Purpose

You can use class items to control the selection of variant parts in a BOM. Variant parts are classified in a class, and the class is entered in the BOM as a class item. When you configure the material, the class is replaced by a suitable variant part.

Class items can help you to simplify maintenance of BOMs for configurable materials:

• You only enter one item for the class, instead of several items for the individual variant parts.
• You do not need to create and assign selection conditions.
• You can classify additional objects in the class at any time, without having to change the BOM.

When you configure the material, the class item is replaced by a specific component.

Prerequisites

You can only uses classes for classifying the following objects as BOM items:

• Materials
• Documents

The class type determines whether a class can be used as a class item in BOMs. In Customizing for the Classification System, the Class node indicator must be set for the class type. In the standard system, class types 200 and 300 are defined for materials, and class type 201 is defined for documents.

Configurable materials can be assigned to classes of class type 300. If a class item is replaced by a configurable material, this material is added to the configuration structure automatically.

Process Flow

1. Create characteristics that describe the objects.
2. Create your class using a class type for class items.

Maintain the additional data for the class (see the SAP Library CA - Cross-Application Components ® Classification (CA-CL) ® Classification (CA-CL) ®Additional Data).

3. Assign objects to the class and assign values to the characteristics of the class for each object.
4. Enter the class as a class item in the BOM of the configurable material – see the SAP Library Bills of Material (PP-BD-BOM).

• 
  
Detail Screens For A Class Item
• 
  
Entering Class Items

See also:

Selection from a Class Item

Variant Classes

In variant configuration, a class is used to hold the characteristics that describe a configurable material. By linking the class to the configurable material, you allow the material to be configured using the characteristics of the class.

You can only use a class in variant configuration if the class has a class type that supports variant configuration. In the standard R/3 System, the class type for variants is class type 300. However, in Customizing for Classification, you can define other class types for variant configuration. In the step Define class types, you can set the Variant class type indicator for a class type.

Once you have created a variant class, you can do the following, as for any other class:

• Classify materials in the class
  These materials do not have to be configurable materials.

• Set up a class hierarchy
  This allows you to use inherited characteristics and restrict characteristic values.

• Use the class to find objects

Class type 300 has 2 other special attributes, in addition to the Variant class indicator:

• In classes of this class type, you can classify objects of different object types. This means that all the objects linked to the configurable material are classified in one class.

For example, if you create a sales order for a configurable material, this order is automatically classified in the variant class.

• You can also use classes of class type 300 as BOM items. For more information, refer to
Classes as BOM Items.

You define these two settings in Customizing for Classification, step Define class types.

Finding Objects in a Class Item

Procedure

You can start the function for finding objects in a class item from the result screen, or in a multi-level, interactive configuration, you can select the class item from the Confign structure:

1. Select the class item and choose Find objects.

You see the characteristics of the class. You can enter characteristic values as search criteria.

2. Choose Find object again.

You see a list of objects that match your search criteria.

3. Select the object you want to copy and choose Copy objects.

However, this is only possible in the simulation, or in configuration processes Order BOM and Sales order (with the setting Manual changes allowed).

Result

On the result screen, the class item is replaced by the object you selected.

Selection from a Class Item: Example

1. Create characteristic REARLIGHT_TYPE, with values Dtoplight Plus, Toplight, and FER.
2. Create class REARLIGHT with class type 200.

Define the following additional data for the class:

· The class can be used in bills of material (BOMs).

· The base unit of measure is piece.

· The item category for the resulting material is L (stock item).

3. You have created 3 materials – R1220, R1221, and R1222.

You classify there 3 materials in class REARLIGHT as shown in the following table:

Material	Value
R1220	Dtoplight Plus
R1221	Toplight
R1222	FER

4. You enter the class as a BOM item in the BOM for configurable material BIKE.



When you enter the BOM item, enter item category K first. You see a dialog box in which you must enter the class name and class type.

The class name for the item is not shown on the material item overview.

5. Assign characteristic REARLIGHT_TYPE to the variant class of configurable material BIKE.

The characteristic is now assigned to both the class item and the configurable material.

6. When you configure the BIKE, you can assign a value to characteristic REARLIGHT_TYPE.

Depending on the value you assign to the characteristic, the relevant material is selected from the class item.

For example, if you assign value ‘Toplight’ to characteristic REARLIGHT_TYPE, the class item is automatically replaced by material R1221.

Selection from a Class Item

Use

You have various options for selecting a specific material or document from a class item (sometimes called "specializing" a class item).

• The class item is automatically replaced according to the characteristic values assigned when the material is configured.

• This means that object dependencies for the class item must make values for the characteristics of the class known.

If the system finds no values for the characteristics in the class item, first it looks for the values in the superior assembly, then if it finds none there, it checks the header material.

• In a multilevel, interactive configuration, the class item can be replaced manually by searching for an object.

However, this is only possible in the simulation, or in configuration processes Order BOM and Sales order (with the setting Manual changes allowed).

Components that are automatically selected from a class item cannot be changed manually in order BOM processing or set processing.

Required Component

If you define in the class or the BOM item data that a component must be selected (Required component), the class item is marked as inconsistent until it is replaced by a material or document.

See also:

Defining Classes as BOM Items

Classification as a Selection Condition

Use

You can classify the materials or documents that you enter as components in a BOM in the Classification System. The bolts that are selected for different variants can be classified in class BOLTS and entered as BOM items. You can use the classification data in variant configuration as a selection condition.

In BOM maintenance, you just define in the BOM item that the item’s classification controls whether it is selected – there is no need to enter a selection condition You can use the classification in any class type.

Prerequisites

The characteristics of the class in which the material or document is classified must all be assigned to the configurable material. The value assigned in configuration must be identical to the classification value before the material or document is selected.

Class BOLTS in class type 001 has characteristics LENGTH and HEAD_SHAPE. To use the classification of bolts as a selection condition, you must assign both characteristics to the variant class. Before a bolt can be selected, both characteristics must have both classification values assigned in configuration.

Activities

On the detail screen of the BOM item in BOM maintenance, enter the class type of the class in which the material is classified, and select Selection condition.

Selecting BOM Items

Use

There are three ways of selecting variant parts in the BOM of a configurable material:

• You enter the variant part as a BOM item and assign selection conditions to it
• You classify the variant part in a class and enter the class as a class item in the BOM.
• You use the classification data of a material or document as a selection condition.

A bike has different rear lights:

§ Dtoplight Plus

§ Toplight

§ FER

You have the following options for controlling which rear light is selected:

a You can create BOM items for the individual rear lights, and use selection conditions to define when each item is selected.

b You can create a class of class type 200 or 300 and classify the three rear lights in the class. You enter the class as a BOM item in the BOM.

When you configure the material, the class is replaced by one rear light.

c The rear lights were classified in the classification system (in a class of class type 001, for example). Characteristic REAR_LIGHT_TYPE has been defined for the rear lights. You assign this characteristic to the variant class.

You enter three items in the BOM for the rear lights. For each item, you define that its classification is used as a selection condition. If you set a value for characteristic REAR_LIGHT_TYPE when you configure the bike, the system looks for a rear light that has this value, and selects a rear light on this basis.

Super BOM

Use

The bill of material (BOM) of a configurable material contains all the components that are required to manufacture the material. The BOM contains components that are only used in specific variants (variant parts), as well as components that are used in all variants (non-variable parts).

This is why BOMs for configurable materials are known as super BOMs.

Features

When you maintain BOMs for configurable materials, there are additional functions:

• You can assign object dependencies to the BOM items for a configurable material.

You can assign the following dependency types to BOM items:

• Selection conditions

To ensure that variant parts are selected when they are needed in a variant, you assign selection conditions to the variant parts.

See Selection Conditions and Selection Conditions for a BOM Item and Operation

• Procedures (actions)

You can use procedures and actions to change field values in a BOM item, such as the component quantity.

See Reference Characteristics in Dependencies and Master Data References in Bills of Material

• You can use classes as BOM items for configurable materials, as well as the other types of component. When you configure the material, the characteristic values you assign can trigger the replacement of the class by a material or a document that is classified in the class. You can use a class item instead of using several BOM items with selection conditions.

• You can use the classification data of a material or document as a selection condition.
• The BOM can contain components that are configurable materials. These configurable materials have item category N (non-stock material).