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 |
General Hardware Description |
|
General Software Description |
|
Additional Application Information |
|
Additional Design Documentation |
|
Additional specifications |
| |
General Test Specification |
|
Architecture |
Block / Schematic Diagrams |
|
|
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) |
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:
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
