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7.1 Object-oriented design using the UML 181

Report
Weather
Report
Weather Status
Information
System
Restart

Shutdown

Reconfigure

Control
System Powersave

Remote
Figure 7.2 Weather Control
station use cases

so on. This is shown in Figure 7.3, which describes the Report weather use case from
Figure 7.2. Examples of some other use cases are on the Web.

7.1.2 Architectural design

Once the interactions between the software system and the system’s environment
have been defined, you use this information as a basis for designing the system
Figure 7.3 Use case architecture. Of course, you need to combine this with your general knowledge of
description—Report
weather the principles of architectural design and with more detailed domain knowledge.

System Weather station
Use case Report weather
Actors Weather information system, Weather station
Dat The weather station sends a summary of the weather data that has been collected from
the instruments in the collection period to the weather information system. The data sent
are the maximum, minimum, and average ground and air temperatures; the maximum,
minimum, and average air pressures; the maximum, minimum, and average wind speeds;
the total rainfall; and the wind direction as sampled at five-minute intervals.
Stimulus The weather information system establishes a satellite communication link with the
weather station and requests transmission of the data.
Response The summarized data are sent to the weather information system.
Comments Weather stations are usually asked to report once per hour but this frequency may differ
from one station to another and may be modified in the future.