OMG Exam OMG-OCUP2-FOUND100 Topic 7 Question 18 Discussion

The execution starts from activity A (as there's no incoming transition).

From A, there's only one outgoing transition leading to activity E.

Following the transition from E, the flow reaches activity C.

There are no further outgoing transitions from C, signifying the end of the valid trace.

Explanation of Why Other Options are Incorrect:

A . E waits for an Event:The diagram doesn't show an explicit wait event associated with activity E. While an event might trigger the initial start of the activity A, the provided trace (A, E, C) focuses on the control flow between the activities themselves.

B . E is always executed faster than B:There's no basis to establish a timing relationship between E and B based solely on the structure of the diagram. The order of execution is A, E, C, but their relative speeds cannot be determined from this information.

D . C waits for tokens on both incoming edges:Activity C has two incoming transitions, but the concept of waiting for tokens on both edges simultaneously doesn't apply here. Since the flow reaches C from activity E, only the transition from E provides the token needed to enable C's execution.

Trace vs. Path

It's important to distinguish between trace and path in an activity diagram:

Trace:A specific sequence of activity executions along a feasible path.

Path:A possible route through the activity diagram, which may or may not be a valid trace depending on the presence of decisions or loops.

In this case, the answer focuses on the valid trace A, E, C, which represents a confirmed sequence of activity executions based on the transitions in the diagram.

Reference

UML 2.5.1 Specification (Superstructure): Sections on Activity Diagramshttps://www.omg.org/spec/UML/2.4/Superstructure/PDF