We can derive the size of the enclosure from this ( Figure
2.9 ). These requirements already include technical aspects for a possible system
design. You will read further below how we handle this. For now, let ??™ s fi rst add
this customer wish as it is.
Pay attention to the direction of the arrowheads. In SysML/UML arrows are
often used in exactly the opposite way of what you would normally expect. As a
rule of thumb, the arrows can be read in the direction they point. The size for the
central unit is derived from the DIN radio compartment ( Figure 2.9 ). Another helpful
rule: arrows are also often dependencies. This means that the enclosure size
depends on the DIN radio compartment, and not vice-versa, which would hardly
make any sense.
There are other requirement relationships that produce a connection to the
design and test models. They answer questions like ??? What does which requirement
implement? ??? and ??? What checks whether or not a requirement is implemented
correctly or at all? ??? These relationships will be explained in the course of our
approach, or in the appropriate SysML chapter (Section 4.
Pages:
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125