Subtractive Configuration

There are three fundamental methods for creating a product variant in variant management: additive configuration Additive Configuration (ˈa-di-tiv kən-ˌfi-gyə-ˈrā-shən) n. Additive configuration is a method for creating product variants by combining modules via standardized interfaces. Learn its role in variant management. , subtractive configuration, and parametric configuration Parametric Configuration (ˌper-ə-ˈme-trik kən-ˌfi-gyə-ˈrā-shən) n. Parametric configuration defines product variants through adjustable parameters like dimensions and geometry, rather than selecting from a fixed set of discrete options. .

Subtractive configuration is a method for creating product variants that begins with a maximum product structure — a 150% BOM 150% BOM (ˌwən-ˌfif-tē pər-ˈsent ˌbil əv mə-ˈtir-ē-əlz) n. A 150% BOM lists all possible components across all product variants, serving as the master structure for subtractive configuration in variant management. — containing all possible components and options for a product family, then derives specific variants by removing the components that are not required.

How subtractive configuration works

The starting point is the 150% BOM (also called the superset configuration or maximum parts list): a single product structure that contains every component across every variant, including options that are mutually exclusive in practice. This master structure is defined once and maintained centrally.

A specific product variant is created by applying configuration rules — expressed in Boolean algebra Boolean Algebra (ˈbü-lē-ən ˈal-ji-brə) n. Boolean algebra provides the logical operators (AND, OR, NOT) used to define valid product configurations and constraints in variant management and CPQ. — that determine which components from the 150% BOM are included in the variant and which are excluded. The result is a 100% BOM: the exact list of components for that specific product.

Under certain circumstances, the 150% BOM itself cannot be physically built, because it contains mutually exclusive options — for example, a diesel engine and an electric drivetrain for the same vehicle platform. This is by design: the 150% BOM is a logical structure, not a production order.

Examples

• Cars — A 150% BOM for a vehicle model contains all engine options (diesel, petrol, hybrid, electric), all trim levels (leather/Alcantara/fabric), and all optional features (sunroof, sport brakes, parking sensors). For each customer order, the configuration rules produce a 100% BOM with exactly the components selected.
• Office desks — All tabletop finishes (white, grey, wood effect), all structural options (height-adjustable/fixed), and all accessories (cable tray, monitor arm bracket, drawer unit) are listed in the 150% BOM. The specific desk configured by a customer subtracts everything not ordered.

When subtractive configuration is appropriate

Subtractive configuration works best when:

• The product family has high variant diversity driven by a stable set of selectable options
• The differences between variants can be expressed as rules (which components to include or exclude)
• Variants share a large proportion of their components
• The configuration logic needs to be maintained centrally (e.g., in an ERP system like SAP LO-VC)

It becomes cumbersome when variants differ fundamentally in their architecture — in those cases, branching Branching (ˈbran-chiŋ) n. Branching creates parallel product variants as independent development paths, without a shared 150% BOM master structure. Learn its benefits and trade-offs. or product line approaches may be more appropriate.

Note: Some products can be modeled with different configuration approaches. A PC, for example, could be configured using either subtractive configuration (starting from a 150% BOM of all processor, memory, and storage options) or additive configuration Additive Configuration (ˈa-di-tiv kən-ˌfi-gyə-ˈrā-shən) n. Additive configuration is a method for creating product variants by combining modules via standardized interfaces. Learn its role in variant management. (assembling selected components from scratch). The right choice depends on the existing product data model and tooling.

Frequently asked questions