Legacy Issue Number: 18709
Source: NASA ( Nicolas Rouquette)
SysML 1.3 section 18.104.22.168 Block says:
SysML establishes four basic classifications of properties belonging to a SysML Block or ValueType.
A property typed by a SysML ValueType is classified as a value property, and always has composite aggregation.
In SysML, we also have Signals.
In UML, Signals can have properties.
How does SysML then classify properties defined in a Signal?
A very strict reading of the SysML spec would suggest that a Signal cannot have any kind of SysML property because a Signal is neither a SysML Block nor a SysML ValueType.
However, this is clearly too restrictive in practice.
I propose expanding SysML's classification of properties to include SysML Blocks, ValueTypes and Signals.
This leads to another question:
What are the legal types of a property belonging to a Signal?
I propose restricting such properties to be typed by SysML ValueTypes only. This corresponds to the practical situation where a Signal carries a data payload I.e., it is a message with some data content.
Allowing a property belonging to a Signal to be typed by a SysML Block or Signal leads to semantic problems what would it mean to send / receive such signals?
Reported: SysML 1.4 — Mon, 13 May 2013 04:00 GMT
Disposition: Deferred — SysML 1.6
Postponed to the next RTF
Updated: Mon, 1 Apr 2019 18:16 GMT