Page 195 - Software and Systems Requirements Engineering in Practice

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C C h a p t e r 5 : Q u a l i t y A t t r i b u t e R e q u i r e m e n t s 161 161
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Refined Business Goal Quality Attribute Quality Attribute Scenario
Support hardware Modifiability Two developers are able to
devices from many integrate a new device into
different manufacturers the system in 320 person
hours.
Support conversions of Modifiability A system administrator
nonstandard units used configures the system to
by the different devices handle the units from a
newly plugged-in field device
in less than three hours.
Support international Modifiability A developer is able to
languages package a version of the
system with new language
support in 80 person hours.
Comply with regulations Performance A life-critical alarm
requiring life-critical should be reported to the
systems, such as fire concerned users within
alarms, to operate three seconds of the
within specific latency occurrence of the event
constraints that generated the alarm.
TABLE 5.6 Quality Attributes and Scenarios Derived from Business Goals
Architectural Drivers
From the features, quality attributes and factors enumerated in earlier
sections, we distill a list of significant architectural drivers. A
prioritized list of such drivers for the building automation system is
shown in Table 5.8.
Architectural drivers 1–5 relate to the quality attribute scenarios
enumerated in Table 5.6. In addition, architectural drivers 1 and 3
also correspond to dynamic reconfiguration, 2 corresponds to
personalization, 4 corresponds to event management, and 5, to alarm
management features respectively enumerated in Table 5.3. Most
architectural drivers relate to the factors identified in Table 5.7. For
instance, the organizational factor concerning new market segments
is reflected in architectural drivers 1–5. These drivers take into account
the flexibility needed to accommodate new field devices and their
calibration, language, and cultural aspects, as well as regulatory
concerns regarding the responsiveness of the system to safety-critical
events. The technological factor related to scalability and
responsiveness and the product factor related to performance and
scalability are addressed through architectural drivers 4, 5, and 6.