OMG OMG Certified UML Professional 2 (OCUP 2) - Foundation Level OMG-OCUP2-FOUND100 Exam Dumps: Updated Questions & Answers (October 2025)

Activity precondition and postcondition constraints are essential for specifying conditions that apply to an activity. Let’s break down the concepts:

Precondition:

A precondition represents a condition that must be true before the activity can start or be invoked.

It ensures that the necessary prerequisites are met before executing the activity.

For example, a precondition for an activity related to booking a flight might be that the user has already logged in to the system.

In UML, preconditions are typically expressed using natural language or constraints.

These constraints can be associated with the entire activity or specific actions within it.

Postcondition:

A postcondition specifies a condition that must be true after the activity completes.

It captures the expected state or outcome resulting from the activity’s execution.

For instance, a postcondition for the flight booking activity might be that the reservation has been successfully confirmed.

Similar to preconditions, postconditions can apply to the entire activity or individual actions within it.

Application Scope:

B is the correct answer because preconditions and postconditions apply only to specific invocations of the activity.

They do not universally apply to all invocations of the same activity.

Different invocations of the same activity may have distinct preconditions and postconditions based on context or input parameters.

Constraining Actions vs. Flow of Objects:

Option C is incorrect because preconditions and postconditions are not primarily used to constrain specific actions within the activity.

Option D is also incorrect because they are not limited to constraining only the flow of objects within the activity.

Instead, preconditions and postconditions focus on the overall conditions for invoking and completing the activity.

In summary, preconditions and postconditions are essential for ensuring the correctness and validity of an activity, but they are context-specific and apply to specific invocations12.

References:

Sparx Systems. “Use Case Diagram - UML 2 Tutorial.” 2

Stack Overflow. “What is the difference between precondition, postcondition, and invariant constraints?” 1

Stack Overflow. “UML Use-case diagram postcondition implementation (with diagram).” 3

The provided image depicts a block diagram with a signal, decisions, and actions. Here's a breakdown of the elements and why answer choice A is the most accurate:

Signal: Represented by a vertical arrow labeled "Signal", indicating an external stimulus that triggers the process.

Decision Diamond labeled "x>0": This diamond represents a decision point based on the condition "x greater than 0". The flow splits into two paths based on whether the condition is True (Yes) or False (No).

Paths from the Decision:

The True (Yes) path leads to an action labeled "a".

The False (No) path leads to an action labeled "b".

Action c: This action is positioned below the decision diamond.

Analysis of Action c's Execution:

Upon receiving a Signal, the decision point is evaluated.

Depending on the value of x:

If x is greater than 0 (True path), action "a" is executed.

If x is not greater than 0 (False path), action "b" is executed.

In either case (True or False), after the corresponding action (a or b) finishes, action "c" is then executed once.

Other Answer Choices Analysis:

B. Two or more Signals must be received... The diagram suggests execution upon receiving one Signal.

C. Action c will get executed twice... The diagram indicates c executes only once after either a or b.

D. Nothing can be said... The diagram conveys a clear sequence of actions based on the signal and the decision.

Having all the UML diagrams of a model maintain the same level of detail is typically required by tools that automatically transform the model into other forms, such as code or other types of models. Consistency in the level of detail across different diagrams ensures that automated tools can reliably interpret and convert the UML diagrams without encountering discrepancies that could lead to errors or misrepresentations in the generated outputs. This consistency is crucial for maintaining the integrity of the transformations and for ensuring that the resultant products accurately reflect the intended design and specifications.

In UML, a filled diamond represents a composite aggregation, also known as a composition. It indicates a whole-part relationship with strong ownership and coincident lifetime of the parts with the whole. Here's what it means in relation to the options provided:

A. This is partially correct. A filled diamond indeed indicates that the Ship instance is responsible for the existence of the associated Person instances, but it is not complete as it does not explicitly state that the Person instances will be deleted when the Ship instance is deleted.

B. This option is the most accurate. A filled diamond represents a composite aggregation, which means that the existence of the Person instances (parts) isdependent on the Ship instance (whole). When the Ship instance is deleted, so are the Person instances it contains.

C. The filled diamond is not a placebo; it has a well-defined meaning in UML, indicating strong ownership and lifecycle dependency between the whole and the part.

D. While the filled diamond does indicate ownership, it specifies more than just an attribute relationship; it indicates that the Ship class has a composition relationship with the Person class. This means that the Ship object contains Person objects as parts of itself, not just as an attribute reference.

E. The filled diamond is connected to the Ship class, not the Person class, so this statement is incorrect. The composition relationship is from Ship to Person, not the other way around.

Based on the UML specification for composite aggregation, the most accurate statement isB: Class Person's existence depends on the ship. It will get deleted when the ship gets deleted. This aligns with the definition of composite aggregation, where the part's lifecycle is dependent on the whole's lifecycle.

In the given UML package diagram fragment, various elements are listed with stereotypes indicating their nature («class», «interface»). Stereotypes are used in UML to extend the vocabulary of UML in order to create new kinds of building blocks. They are typically enclosed in guillemets (« »).

The last element, 'six', does not have a stereotype indicating whether it's a class, interface, or some other kind of element. This lack of a stereotype leads to ambiguity about the nature of 'six'. Therefore, the fragment is considered invalid due to this omission.

All the other options do not constitute an error in the UML fragment: A) A list of elements is allowed in a package body. B) Visibility is not required for every element, especially within package diagrams. C) Interfaces are allowed in packages. D) Private elements are allowed in a package. E) Protected elements are also allowed in a package.

Therefore, the correct answer is:

F. Element six is missing its stereotype.

The diagram shows a UML Sequence Diagram where two messages are being exchanged between lifelines representing instances of objects:m(C)is being sent fromv1tov2, andm(D)is being sent back fromv2tov1.

In a sequence diagram, the vertical order of message arrows shows the sequence of interactions, with time proceeding down the page. Since the messagem(C)is shown abovem(D), this means thatm(C)occurs beforem(D). The receipt ofm(C)byv2[B]must therefore occur beforev2[B]can sendm(D)back tov1[B].

Therefore, the statement "Receivingm(C)must come before sendingm(D)" is always true in this diagram.

B, C, and D are not necessarily true based on the diagram alone: B) "Sending m(D) is the first occurrence of this scenario" is not depicted. C) "Receiving m(D) is the last occurrence of this scenario" is also not depicted. D) "All occurrences of v[1] will happen before all occurrences of v[3]" is not something we can infer from this diagram since v[3] is not involved in the interactions shown.

Therefore, the correct answer is:

A. Receiving m(C) must come before sending m(D).

The provided diagram depicts aDataTypenamed Route with operations, attributes, and associations to aClassnamed City. In UML, aDataTypeis a type of classifier that specifiesthe values that do not have identity (i.e., are not distinguishable from other objects).DataTypesmay contain Attributes and Operations, so options B and C are incorrect.

However,DataTypesshould not have associations toClassesbecauseDataTypesare meant to be value types without identity, and associations typically imply a relationship between instances (which have identity). Thus, the presence of associations from Route to City is not consistent with the definition of aDataType.

References:

UML 2.x Superstructure Specification: Sections on Classifiers and DataTypes provide definitions of what constitutes aDataTypeand what features they can have. They specifically mention thatDataTypesare kinds of classifiers that do not have identity and are often used to type attributes.

UML 2.x Infrastructure Specification: This foundational document gives additional context on the semantics of different types of classifiers, includingDataTypes, and how they relate to other elements in a UML model.

Abstraction in UML and software modeling often incorporates the technique of information hiding. Information hiding is a principle that supports abstraction by ensuring that unnecessary details about software components are not exposed to other parts of the system. This encapsulation strengthens modularity and keeps various parts of the program independent of one another, which simplifies complexity in large systems. Abstraction and information hiding are closely related; abstraction focuses on the high-level structure of the system, while information hiding protects the internal states and functionality of components, allowing changes without extensive impact on other system parts.

In the context of UML Use Case diagrams, the "owner" of a use case is the system or unit that provides the services of the use case. The use case "Book a car" is contained within the "Rental system" boundary, which is represented as a rectangle in the diagram. This indicates that "Book a car" is a function or service provided by the "Rental system."

The "Call-Center Agent" is an actor that interacts with the use case, but it does not own it. The "Car Rental" seems to be a higher-level packaging element (like a system name), but it is not the immediate container of the use case. The "Booking unit" is a part of the "Rental system" that is specifically responsible for the "Book a car" functionality, but in terms of UML semantics, the use case is owned by the system that contains it, which in this case is the "Rental system."

Therefore, the correct answer is:

C. Rental system

Start Node: Represented by a black circle, indicating the starting point of the activity.

Action a: Represented by a rounded rectangle, signifying an action or step within the activity.

Action READY: Another rounded rectangle representing an action.

End Node: A circle with a black dot inside, marking the end point of the activity.

Based on the common elements in both Act1 and Act2:

The activity starts at the designated start node.

It proceeds to action "a".

Then it moves to action "READY".

Finally, it reaches the end node, signifying completion.

There are no additional branches or loops that would allow for re-starting the activity or re-executing action "a" multiple times.

Analysis of Other Options:

B. Initial and final nodes are optional... While it's true that initial and final nodes can be implicit in some cases, well-formed activity diagrams typically include them for clarity. Here, both diagrams have them explicitly.

C. In diagram Act1. action a can get executed once... There's no basis to claim a difference in the number of executions of action "a" between the two diagrams.

D. Diagram Act2 is incomplete... Both diagrams seem complete as they have proper start and end nodes, and the flow goes from start to finish without any ambiguity.

Therefore, considering the structure and execution flow, both Act1 and Act2 will end after the "READY" action, and no further signals will be accepted, making answer A the most accurate description.