43 ), which are commonly used in systems engineering.
4.5 Block Diagrams
FIGURE 4-42
Example for association blocks.
ibd [block] Hose
bdd [package] Pump system
?«block?»
Pump system
?«block?»
Container
?«block?»
Pump
source 1 destination 1
pump
0..2
tank
0..1
?«block?»
Hose values
isOn:Boolean
?«block?»
Valve v
1
p 1
?«participant?»
{endtank}
tankInLink:Container
?«participant?»
{endpump}
pumpInLink:Pump
v:Valve
254 CHAPTER 4 SysML??”The Systems Modeling Language
4.6 The Parametric Diagram
SysML allows you to define parametric relationships between properties of blocks.
For example, Newton ??™ s physical law says that force equals mass times acceleration
( f m * a ). The mass results from the sum of the masses of the single blocks.
Acceleration is calculated from the properties of the drive of a system (e.g., a flying
object). Now force can also be computed with Newton ??™ s law.
We can model such relationships to integrate performance or reliability models
in the system model. This allows us, for example, to check alternative design
studies with regard to response times, costs, and weight of the system.
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