# 1.2.2b Product Structure, Bill of Material, Product Family, Product Variant, Commonality: Product-Related Objects

### Intended learning outcomes: Explain the product structure and the bill of material. Differentiate between a convergent and a divergent product structure. Describe the concepts of product family, product variant, and commonality.

Continuation from previous subsection (1.2.2).

Product structure is the structured list of components to be used in order to manufacture a product, understood as a whole-part hierarchy.
A structure level, or simply level, is assigned to every part or assembly in a product structure. It signifies the relative level in which that part or assembly is used within the product structure ([ASCM22]).

The (structure) level stands in inverse relation to the relative depth of the components in the product structure. End products generally have the level 0. The direct components of an end product have the level 1. A component in an assembly has a level code one unit higher than the assembly.

A design structure level is a structure level from the point of view of product design.

Bill of material and nomenclature are other terms for a convergent product structure (in contrast to divergent product structure, where we usually speak of recipes; see also the definition of these concepts in Section 4.4.2).

The quantity required or quantity per or usage quantity is the number of components per unit of measure of the next higher level product into which the component is built. The cumulative quantity per of each component in the end product is thus the product of quantities required along the product structure.

The example in Figure 1.2.2.2 shows a bill of material, that is, a convergent product structure with two (structure) levels.

Fig. 1.2.2.2        A product structure (bill of material) with two (structure) levels.

Item 107421 is the end product composed of the two assemblies 208921 and 218743. Each assembly, in turn, has two components. The quantity required is given in parentheses. As an example of cumulative quantity per, in 107421 there are 2 · 3 = 6 components 390716.

The following exercise shows a bill of material, that is, a convergent product structure with two (structure) levels.
Item 107421 is the end product composed of the two assemblies 208921 and 218743. Each assembly, in turn, has two components. The quantity required is given in parentheses. As an example of cumulative quantity per, in 107421 there are 2 * 3 = 6 components 390716.
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`The low-level code is a number that identifies the lowest level in any bill of material at which a particular component appears ([ASCM22]).`

The low-level code is generally calculated by a computer program.

A product family, or product line, is a group of products having similar features (such as form or material) or similar functions, similar product structure with a high percentage of the same components or components from the same family, and a high percentage of the same processes in the process plan. Cf. [ASCM22].

A product variant, or — simply — a variant, is a specific product in a product family.
An option is a choice — often mandatory and from a limited selection — that must be made by the customer or company when customizing the end product. Cf. [ASCM22].

Commonality is a condition where a given component is used in multiple products. Cf. [ASCM22].

A product family is designed as such as early as the product design phase. Throughout its life cycle, it will be expanded where desired. The product structure of each variant is different, but according to its definition, it is based on a high degree of commonality.

Quiz on Chapter 1.2.2.: not yet available

Product Structure and Product Family[kml_flashembed movie="https://opess.ethz.ch/wp-content/uploads/elements/Q_122.swf" height="75%" width="100%" /]

## Course section 1.2: Subsections and their intended learning outcomes

• ##### 1.2 Business Objects

Intended learning outcomes: Present business-partner, and order-related business objects in detail. Explain product-related, process-related, and resource-related business objects. Produce an overview on rough-cut business objects.

• ##### 1.2.1 Customer, Supplier: Business-Partner Objects; Order, Customer Order, Procurement Order, Production Order, Overhead Order: Order-Related Business Objects

Intended learning outcomes: Present in detail the order as a business object. Produce an overview on terms such as customer, supplier, business partner, due date, customer order, procurement order, production order, overhead order.

• ##### 1.2.1b Order Promising, Order Confirmation, Order Status, Order Header, Order Main Section, Order Footer: Order-Related Business Objects

Intended learning outcomes: Produce an overview on terms such as order promising, order confirmation, order status. Differentiate between order positions for items (to be) delivered and labor (to be) performed.

• ##### 1.2.2 Item, Component, End Product, Assembly, Raw Material, Spare Part, Item Family: Product-Related Objects

Intended learning outcomes: Produce an overview on business objects such as item, specializations thereof (particularly part and component), spare part and item family.

• ##### 1.2.2b Product Structure, Bill of Material, Product Family, Product Variant, Commonality: Product-Related Objects

Intended learning outcomes: Explain the product structure and the bill of material. Differentiate between a convergent and a divergent product structure. Describe the concepts of product family, product variant, and commonality.

• ##### 1.2.3 Operation, Operation Time, Setup, Run Time, Routing Sheet, Critical Path, Interoperation Time, Production Lead Time: Process-Related Business Objects

Intended learning outcomes: Present in detail business objects such as operation, setup and run time. Explain the routing sheet, the critical path, interoperation time and the production lead time.

• ##### 1.2.3b Production Structure, Product Module, Cumulative Lead Time, Process Plan, Lead-Time Offset: Process-Related Business Objects

Intended learning outcomes: Describe the production structure, the product module, and the cumulative lead time. Disclose the process plan. and the lead-time offset.

• ##### 1.2.4 Employees, Facilities, Workstation, Production Equipment, Work Center, Capacity, Load, Standard Load, Actual Load: Resource-Related Business Objects

Intended learning outcomes: Produce an overview on terms such as employees, facilities, workstations, production equipment, work center, capacity, load, work-center load. Differentiate between standard load and actual load

• ##### 1.2.4b Work Center Load, Load Profile, Capacity Utilization, Work Center Efficiency, Rated Capacity: Resource-Related Business Objects

Explain the work-center load and the load profile of a work center. Disclose capacity utilization and work center efficiency. Differentiate between rated capacity and theoretical capacity.

• ##### 1.2.5 Rough-Cut Product Structure, Rough-Cut Work Center, Rough-Cut Operation, Rough-Cut Process Plan: Rough-Cut Business Objects

Intended learning outcomes: Identify reasons and principles for defining rough-cut business objects. Disclose the rough-cut product structure, the rough-cut work center, the rough-cut operation, and the rough-cut process plan. Explain a way to derive a rough-cut process plan from a detailed process plan.

• ##### 1.2.5b Bill of Resources, Product Load Profile: Rough-Cut Business Objects

Intended learning outcomes: Describe the bill of resources. Explain a way to establish a product load profile from a rough-cut process plan.