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Component Structure

The requirements and the product specifications for a system are described either in separate views within one document instance or in separate instances containing only one view. For example, a system can be an ABS system, cruise control, a control unit or even just a sensor. A system can be assigned a part number (not mandatory).

A system is described as a part type. The specifications for a part type roughly encompass the following areas:
General Product Data
Key Data
Operating Environment
Useful Life
Reliability
General Hardware Description
General Software Description
Additional Application Information
Adjustment
Maintenance
Failure Management
General Conditions
Additional Design Documentation
Additional specifications
General Test Specification
Behaviour
Architecture
Block / Schematic Diagrams
Interfaces
Signals
Connection Components
Connections
Networks
Electrical Characteristics
Environmental Characteristics
Other Physical Characteristics
Construction
Human Machine Interface

The structure of a system (hierarchical component structure) is described indirectly. To understand this better, there are three terms with which one should be familiar:
Part Type 

A part type is a library element which can be used ("instantiated") in a system or higher ranking part type through mounting. A part type has no description of use-related information.

Examples: a control unit, a sensor, an actuator

Part 

A part is a mounted part type or a part type in use. It is mounted or employed in a higher ranking system or part type. A part inherits all characteristics of the respective part type. The part itself has a description of use-related information.

Examples: the control unit in an ABS system, the sensor on the left front wheel in the ABS system, the sensor on the right rear wheel in the ABS system

Part Definition 

A part definition is a part type with all accessory parts (instances).

Example:

ABS system (part type)
Control unit (part)
Actuator (part)
Sensor front left in ABS system (part)
Sensor front right in ABS system (part)
Sensor rear left in ABS system (part)
Sensor rear right in ABS system (part)

In this way, a hierarchical component structure is created through successive mounting of part types in the higher ranking system or in higher ranking part types.

The following areas for use-related description are provided for each part of a component. All parameters deviating from the part type (naturally lower requirements than for the part type) can be defined here:
General Product Data
Operating Environment
Useful Life
Reliability
Electrical Characteristics
Environmental Characteristics
Other Physical Characteristics

An ABS system consisting of a control unit, a sensor and an actuator (which itself consists of a cylinder and a valve) would be described by means of a part type ABS, possibly with use-related requirements for the sensor and actuator. Additionally, the sensor and actuator are also specified as part types. This example is illustrated in the following figure:
Figure 3: An example of a component structure

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