Häufig gestellte Fragen
What is the difference between Configure-to-Order (CTO), Make-to-Order (MTO) and Engineer-to-Order (ETO)?
With Configure-to-Order – the typical model of variant manufacturing – the customer selects characteristics from a fixed, predefined option space, from which the system automatically derives a concrete bill of materials and a routing without any new engineering. Make-to-Order refers more generally to production to order after an order is received, often from stocked standard components, but not necessarily with configurator logic. Engineer-to-Order, by contrast, stands for a considerably higher degree of configuration freedom, where substantial new engineering is required per order and sometimes new components or rules have to be created. In practice the boundaries blur, and one goal of good ERP concepts is to convert as much ETO business as possible into manageable CTO business through standardisation.
How does the maximum or 150 percent bill of materials work in variant manufacturing?
The maximum bill of materials – often also called a 150 percent BOM or super BOM – contains all theoretically possible components and characteristics of a configurable product in a single maintainable structure. With the common subtractive configuration approach, the concrete 100 percent BOM of the chosen variant is created from this 150 percent structure by removing items that are not needed. Which parts are actually included for which combination of characteristics is controlled by stored variant rules, conditions and exclusions. This approach avoids having to create a separate item for every combination and reduces maintenance effort considerably, because only the base model and its rule set need to be kept up to date.
Which configuration methods exist in variant manufacturing?
In practice, three methods are commonly distinguished: subtractive, additive and rule-based or parametric configuration. In subtractive configuration, the finished variant is created from a maximum or 150 percent bill of materials by deleting items that are not required; it is considered the most widespread form. Additive configuration, conversely, assembles the product modularly from individual building blocks via defined interfaces, for example along a BOM or installation logic. Rule-based or parametric configuration, sometimes referred to as design automation, controls dimensions, components and in some cases even 3D geometries via formulas and rules and is considered the most powerful but also the most demanding variant; which method fits depends heavily on the product range and engineering depth.
How does a CPQ system differ from an ERP variant configurator?
An ERP variant configurator is built primarily for manufacturing and generates stable, versioned, production-ready bills of materials and routings that flow directly into materials planning and the production order. CPQ – the abbreviation stands for Configure, Price, Quote – starts in sales instead, is often intertwined with the CRM and is intended to help staff quickly create error-free quotations for complex products without immediately generating new material numbers or bills of materials in the ERP. Ideally the two work together in a complementary way: CPQ delivers validated, sales-ready configurations and protects the ERP from incomplete input, while the ERP logic handles the technical derivation. Whether both components are needed separately or an integrated configurator is sufficient depends on the business model and quotation complexity.
For which industries and companies is variant manufacturing typical?
Variant manufacturing is common wherever customers expect many individual versions of a base product, for example in mechanical and plant engineering, the furniture and wood industry, gates and windows, or technical components. Industry observations on mechanical and plant engineering often cite rough orders of magnitude according to which a substantial share of products is manufactured as variants and only a smaller share is pure standard production; such shares vary considerably depending on the source, segment and survey. It is characteristic that even a few standard components in combination lead to a very large number of possible variants. For companies facing this so-called variant diversity, a configurator-based approach in the ERP is usually more economical than maintaining thousands of individual items.
What requirements should an ERP system meet for variant manufacturing?
A powerful rule logic is central, one that can cleanly map dependencies, conditions and exclusions between characteristics so that only permissible combinations can be configured. It is equally important that bills of materials and routings can be variantised together and that a variant configured in the quotation is carried over identically all the way into the production order and costing. For engineering-intensive variants, a connection to CAD or PLM systems also makes sense, and commercially, configuration and price should flow cleanly into quotation and order. Since the greatest challenge of variant manufacturing is the complexity and maintenance effort of master data, disciplined upkeep of the rule set is ultimately crucial, because errors in the model affect all derived variants.