UMLR — No ReadParameterAction or WriteParameterAction

One difference between UML activity and BPEL process is that all
data flows in UML must be explicit through connections between
activity parameter nodes, pins, central buffer nodes, and/or data
store nodes. UML activities can also have structural features and
variables which allow data to be passed between actions without
object flows, corresponding more like BPEL variable references.

However, input and output parameters have no such indirect access.
All actions that need information from parameters have to be
connected through object flows. This is inconsistent and can lead to
complex activity models because of the need for a large number of
ForkNodes and ObjectFlows in order to access Activity parameters.

UML2 should support actions to read and write parameters similar to
reading and writing variables. The ActinInputPins can be used to
simplify parameters in activities.