I am reading in Chapter 8 of Agile Systems Engineering, while simultaneously reviewing the example model TWrecks1.rpy and have some questions.
in ibCommCoord there are three flowProperties called
cmdProximalJointAngle:JointRadian cmdMedialJointAngle:JointRadian cmdDistalJointAngle:JointRadian
These are combined into the message CommandedJointAngleMsg:CANMsg with the following mapping:
Data0:unsigned char = Low byte Proximal Angle Data1:unsigned char = High byte Proximal Angle Data2:unsigned char = Low byte Medial Angle Data3:unsigned char = High byte Medial Angle Data4:unsigned char = Low byte Distal Angle Data5:unsigned char = High byte Distal Angle
In paint it would look something like this:
Now to my questions:
- Why are there no explicit relation between the logical flowProperties and the physical data? Wouldn't that kind of traceability be beneficial to know how the logical data schema is refined into the physical? It feels unsatisfying on relying on the semantics of the text string to indicate traceability.
- If I where to add such a relation how would I do it in the best way?
To I have tried to use «allocate» and «dependency», but that can only be done between the interface specification and the flow property and not to the exact value (Data0, Data1, ...). See below:
Thanks in advance!