Page 71 - Software and Systems Requirements Engineering in Practice

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C h a p t e r 3 : E E l i c i t i n g R e q u i r e m e n t s 43 43
hex head screws.” Meetings to elicit requirements can be sometimes
chaotic, with customers rambling or not necessarily focusing on one
specific topic. While it is important to have stakeholders’ focus, it is
also important not to lose any worthwhile information. Therefore,
when stakeholder requests are captured, it is important to tag the
information recorded with one or more attributes describing the
level of the captured information, along with which stakeholder is
requesting it. For example,
“We want to have the safest car on the market. So we plan to have
an interlock system between the brake and the transmission. The
interlock will decouple the transmission when the brake is pressed.
We should use ½-inch stainless steel for the decoupling rod for safety
purposes, and to prevent corrosion in climates where salt is used on
the roads from eroding the coupling.”
In this example there are requirements at several levels, along
with some design decisions mixed in with the requirements. When
captured and placed in a requirements database, the tagging might
look as shown in Table 3.1.
Note that the selection of stainless steel was removed because it
was a proposed solution, not a requirement.
Failure to Accurately Identify Stakeholders
Imagine being at a meeting with ten or fifteen stakeholders
representing hospitals and health care networks. One stakeholder
suggests a product feature that would allow patients or doctors to
schedule appointments for medical services over the web. Another
stakeholder feels that it is a good idea, but not as urgent as having
doctors schedule appointments and services from their PDAs. During
prioritization meetings it is determined that both requests cannot be
satisfied in the first release of the hospital scheduling system. One of
the requests came from a ten-thousand-bed health care network, and
the other request came from a small, one-hundred-bed hospital.
Request Request Type (or Level) Stakeholder
Safest Car on the Business Goal Sales VP Smith
Highway
Interlock Between Customer Requirement Rental Car
Brake and VP Jones
Transmission
Corrosion- System Requirement Engineering
Resistant Coupling Mgr. Carlson
Mechanism
TABLE 3.1 Level of Requirements