Various product structure types are available in literature.
Their definitions often differ greatly. This section discusses some of the most
commonly used product structuring models that can be used to control diversity
in an organization. (See Figure z)
Product Structure Models by SCHUH
Construction Kits or Baukasten
system makes it possible to create different products from a pre-defined number
of building blocks. Typical of these systems is the use of one or a few basic
bodies or basic structures on the basis of which different products can be
configured. In contrast to modular design, the interfaces exist in the first
place between the add-on parts and the base body. This type of product
structuring is often used in plant construction.
Package building combines add-on parts for various functions
or equipment in one package. This limits the configuration options of a product.
Package formation is often used in the automotive industry, example. for
special sports or equipment packages.
Series have the same type of attachments. These models are
offered in different sizes. This type of product structuring is found
predominantly in structurally complex products like turbines and engines.
Modules are independent function blocks that can be combined
in many ways due to standardized interfaces. They make it possible to produce a
large number of end variants with a small number of modules.
A clear demarcation of the aforementioned product structure
types is not clearly possible due to their different origin and history. Thus,
in practical applications, the different types often overlap.
The process or activity of structuring a product in modules
is called modularization. Modularity represents the characteristics of a
product structure. A modular system, which is composed of modules, is a result
of the modularization process and possesses an attribute called modularity. It
can be considered as a technique to balance the opposing forces of
standardization and customization.
3.4.1 The Concept
The concept of modular design revolves around the development of products
through modules which are building blocks with specifications of functionality
and interface. Replacing a module with another module leads to a new product
variant. The traditional definition of a building block does not take
functionality into consideration. But a module should possess some kind of
functionality with respect to the final product. Therefore, a module is
directly linked to a specific function of the finished product and can be
considered as physical realization of a function. Figure a depicts function and module types in a modular and
Figure a Function and Module Types
Considering the example of standardizing the design process of
a robotic end-of-arm tool for different composite handling applications, we can
use functionality as a means to divide an EOAT into modules. For example, the gripping
function of a tool is realized through its end-effectors. Therefore, we can define
end-effector modules which are directly linked to the tools gripping function. Similarly,
other functions can also be identified and their physical representations can be
grouped into modules. Chapter 5 explains the complete modular design structure of
our standardization process.
Another important feature of a module is the presence of a standard
interface for higher flexibility and adaptation.