The image depicts a state machine with the following states:
S1
S2
The state machine transitions are labeled as follows:
gxSH - This triggers the transition from the initial state to S1.
E - This event triggers the transition from S11 to S21.
exS1 - This signifies exiting state S1.
exS11 - This signifies exiting state S11.
entS2 - This signifies entering state S2.
entS21 - This signifies entering state S21.
actnE - This indicates an action associated with the E event.
Given the state machine is currently in state S11 and an event of type E occurs, here's the sequence of behavior executions:
actnE: The action associated with event E is executed.
exS11: The state machine exits state S11.
exS1: Since S11 is nested within S1, exiting S11 also implicitly triggers exiting S1.
entS2: The state machine enters state S2.
entS21: The state machine enters the nested state S21.
Justification for excluding other options:
Option A (actnE; exS1; exS11: entS21; entS2) has the order of entering S2 and S21 reversed.
Option C (exS11; actnE; entS2) omits the execution of the action associated with event E.
Option D (gxSH; exS1; actnE; entS2) includes the irrelevant initial transition trigger (gxSH).
Option E (exS11; exS1; actnE; entS2; entS21) has an extra exiting of state S1, which is not part of the valid transition path.
Following the state transitions and action triggers depicted in the state machine diagram, option B accurately reflects the sequence of behaviors that occur when event E triggers a transition from state S11.
Questions 5
Choose the correct answer:
Which statement is true about the following diagram?
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.
References
UML 2.5.1 Specification (Superstructure): Sections on Activity Diagrams https://www.omg.org/spec/UML/2.4/Superstructure/PDF
Questions 6
Choose the correct answer:
Which statement is correct about a FlowFmalNode in an Activity?
Options:
A.
FlowFinalNodes do not appear in activities: they are used in State Machines.
B.
FlowFinalNodes do not appear in activities; the proper element for this use is NoneEndEvent.
C.
A token that reaches a FlowFinalNode causes all execution within the activity to cease.
D.
A token that reaches a FlowFmalNode signifies the conclusion of execution along that flow although execution elsewhere within the activity may continue.
Here's a breakdown of why option D is correct and why the other options aren't:
FlowFinalNode Purpose:In UML activity diagrams, a FlowFinalNode represents a termination point for a specific control flow within an activity. It does not end the activity itself but rather the path along which it is placed.
Analysis of Other Options:
References
UML 2.5.1 Specification (Superstructure): Sections on Activity Diagrams, FlowFinalNode. https://www.omg.org/spec/UML/2.5.1/
UML 2 Foundation concepts for activity diagrams, there are three valid action notations shown. Here's a breakdown of the elements and why answer D is the most accurate:
The diagram displays an activity diagram with a main flow and a fork followed by a join.
Main Flow: This starts with an action labeled "Fill Order".
Fork: The path splits into two branches after "Fill Order".
Branch 1: This branch leads to an action labeled "Print Paycheck".
Branch 2: This branch leads to an action labeled "Send Invoice".
Join: The two branches converge into a join element.
Following the Join: An action labeled "End" is present after the join.
Explanation for Valid Actions:
Fill Order: This clearly represents an action within the activity diagram.
Print Paycheck: This is another valid action on a separate branch.
Send Invoice: Similarly, this is an action on the other branch.
Explanation for Why Other Options are Incorrect:
A. 0: There are clearly multiple actions depicted in the diagram.
B. 1: There are more than one valid action shown.
C. 2: While there are actions before the fork, there's also a valid action ("End") after the join.
E. 4: Counting the join element as an action results in an overcount. Joins represent control flow elements to synchronize multiple paths, not actions themselves.
References
UML 2.5.1 Specification (Superstructure): Sections on Activity Diagrams and Actions https://www.omg.org/spec/UML/2.5.1/