SYSMLR — Flow properties and activity paramters

The SysML flow properties specify elementary flows (nature and direction) that can cross the boundary of a block through a port.

According to the functional approaches of systems engineering, an entering flow when getting over the boundary of a block is handled as an input by at least one function of the block. An outgoing flow getting out the boundary of the same block is produced as an output by at least one function.

Activity diagrams are used for carrying out functional graphs with SysML. Inputs and outputs of SysML activities are specified by parameters. Nevertheless SysML does not seem to provide any mean to relate activity input / output parameters to the flow properties. This entails that the unfortunate SysML developers, after having made careful and strenuous efforts for specifying the block interfaces with flow properties and ports, have no other solution than to redo exactly the same work for specifying the inputs / outputs of the functional architecture as activity parameters (or vice-versa). Moreover, there is no mean to ensure consistency in the SysML model between the flow properties and the activity parameters and neither between the ports and the activity pins.

A solution would be to enable to use flow properties like parameters as activity inputs / outputs.

Defer

Postponed to the next RTF