OMG-OCUP2-ADV300 OMG Certified UML Professional 2 (OCUP 2) - Advanced Level Questions and Answers

In UML, a template is a parameterizable element, and the parameters for a template are typically classes or other classifiers. According to the UML 2.x Superstructure Specification, all subclasses of Classifier can potentially be used as template parameters. This includes classes, components, datatypes, interfaces, signals, and more. The specification provides the flexibility to define template parameters that are specialized types, allowing for powerful and reusable designs. The ability to parameterize these elements is foundational to creating generic and reusable model elements, which is a core capability of the UML's templating mechanism.

In UML, the «bind» relationship is used to specify that a class is a template instantiation of a template class, where actual parameters are bound to the formal parameters of the template class1. However, in the case of the relationship between a concrete class like Vector and an abstract class like AbstractList, the correct relationship should be Generalization, not «bind».

Generalization is a taxonomic relationship between a more general classifier and a more specific classifier. Each instance of the specific classifier is also an instance of the general classifier1. Thus, Vector being a concrete implementation of AbstractList, should inherit from AbstractList, which is correctly represented by a Generalization relationship in UML.

The other options can be evaluated as follows:

• Option A: The upper limit for the size of PhontyQueue is a design decision that should be based on the requirements and use cases of the application. It is not inherently incorrect in UML to have a specific upper limit.
• Option C: The Generalization relationship is correctly used between PriorityQueue and AbstractQueue as it represents inheritance in UML.
• Option D: While it is true that template parameters are typically defined at the top of the hierarchy, the statement is too absolute. In UML, template parameters can be added to specialized classes, but it depends on the specific design and requirements. Therefore, without additional context, this statement cannot be deemed universally valid.

In conclusion, the most applicable and valid review comment is option B, which correctly identifies the misuse of the «bind» relationship in the context of the class diagram provided.

In UML, the keyword «isSubstitutable» is used to indicate that instances of one classifier may be used in place of instances of another classifier. This concept is commonly applied in the context of generalization, where a subclass can be substituted for its superclass. The substitutability is a fundamental principle of object-oriented design, particularly in the Liskov Substitution Principle, which states that objects of a superclass should be replaceable with objects of a subclass without affecting the correctness of the program. This principle is reflected in UML's support for polymorphism, which is implicit in the generalization relationships between classifiers.

The sequence diagram depicts interactions over time between different entities. To determine the order of events, one must follow the flow of messages from top to bottom, as this represents the chronological order in which these interactions occur.

In the given diagram, 'HH' is a lifeline that is eventually destroyed, indicated by the finalization (cross) symbol at the bottom of its lifeline. The reception of 'z' is an event that happens between the lifelines labeled 'xX' and 'yY', and the reception of 'w' is an event that happens between 'q:Q' and 'p:P'. Since sequence diagrams are read from top to bottom, the message 'w' is the last one before the destruction of 'q:Q', which isindicated by the destruction occurrence specification (cross) at the bottom of 'q:Q'. Therefore, the last event that occurs according to the diagram is the reception of 'w'.

References to UML 2 specifications include:

• UML 2.5 Specification (formal/2017-12-05), by Object Management Group, which describes the semantics of sequence diagrams, interactions, and the interpretation of message flows and lifeline termination.
• Sequence Diagrams in UML, which explain the order of interaction and message passing between lifelines.

In Option C, the propertiessuitable road surfaceandaverage speedhave been redefined in the subclassesRecumbent BikeandRacing Bike. The use of the{redefines}keyword in UML signifies that the subclass will provide its own specific values for these properties, overriding the general ones provided by the superclassBicycle. This is the correct way to enforce that each specialization ofBicyclehas a unique set of values for these attributes, as redefinition allows for the customization of inherited properties on a per-subclass basis. The use of{redefines}is specified in the UML 2.x Superstructure Specification, which describes how properties inherited from a superclass can be customized by subclasses.

Protocol Conformance in UML is a relationship between protocol state machines that ensures consistency in behavior inheritance:

• A.Incorrect as it describes a general-to-inherited relationship, which is not the focus of protocol conformance.
• B.Incorrect, as it describes a relationship the wrong way around (general to nested).
• C.Correct. Protocol Conformance ensures that a specific Protocol State Machine conforms to the rules and constraints specified by a redefined, more general Protocol State Machine.
• D.Incorrect, because it generally describes conformance but does not specifically focus on the relationship between specific and general state machines in the context of protocols.

References:

• UML Specification: Protocol State Machines section.
• Specifics of protocol conformance are detailed under state machine and classifier behaviors in the UML 2.5 Documentation.

A UML profile can define several different elements to extend the UML for a specific domain, platform, or purpose. Besides stereotypes, a profile can define DataTypes and Enumerations, which can be used within Stereotypes to type the tagged values. A profile can also define Classes, which can be used as base classes for stereotypes. However, a profile does not typically define instances of elements, such as Objects, nor does it define composite structures, such as Components. The intent of a profile is to adapt existing metamodel elements through the use of stereotypes, tag definitions, and constraints rather than to create instances or define system architectures. This definition and use of a profile are aligned with the guidelines in the UML 2.x Superstructure Specification, which outlines what elements a profile can define within the UML framework.

To orchestrate multiple actions within UML, a modeler should use StructuredActivityNodes:

• A.Extending Behavior and adding desired Actions is not specifically about coordinating multiple actions; it's about defining new behaviors.
• B.Correct. StructuredActivityNodes are a part of UML that provides a mechanism to group a set of actions together and manage the data flows between them, thus coordinating the actions.
• C.Using the standard Action and adding desired tag values does not inherently coordinate actions.
• D.Extending Action and specifying constraints to be relaxed or removed does not directly relate to coordinating other actions.

References:

• UML Specification: Activities section, which describes the use of StructuredActivityNodes.
• The use of StructuredActivityNodes for coordinating actions is elaborated in the UML 2.5 Documentation under Activity Diagrams.

In UML, a simple State can indeed be redefined, but the specifics of how it is redefined matter:

• Ais incorrect as redefinition of States, including simple States, is permitted.
• Bis correct. A simple State can be effectively removed or altered through redefinition in a derived StateMachine, which could include changing its type or characteristics.
• Csuggests that a simple State can be turned into a composite State. While theoretically possible in the context of redefinition, this option might be considered a significant alteration that could be misleading without additional context.
• Dis incorrect; UML does support State Redefinition.

References:

• UML Specification, particularly the sections on Redefinition and StateMachines.
• Detailed rules on state redefinition are outlined in the UML 2.5 Documentation, specifically under StateMachine specializations.

In the given UML activity diagram, "action 1" is an action that executes the classifier behavior (intrinsic behavior) of an instance. The correct UML action that represents this behavior is:

• A. CallBehaviorActionis used to call a behavior directly, but not necessarily the classifier behavior of the input object.
• B. CallOperationActionis used to call an operation, which is not the intrinsic behavior of an instance.
• C. StartObjectBehaviorActionis the correct answer. This action starts the execution of the classifier behavior of an object.
• D. CallClassifierBehaviorActionis not a standard UML action.

References:

• UML Specification: Actions section, which explains the various types of actions including the StartObjectBehaviorAction.
• Further details about actions that initiate behaviors of objects can be found in the UML 2.5 Documentation, specifically in the chapters discussing Actions in Activity diagrams.

The Model-Driven Architecture (MDA) approach is a design methodology that covers the entire software development lifecycle, from requirements to technology implementation. It emphasizes the use of models as the primary artifacts in the development process, allowing for a more abstract and high-level approach to software design. MDA supports the transformation of models from platform-independent models (PIMs) to platform-specific models (PSMs) and ultimately to code, ensuring that the initial requirements are accurately reflected in the final technology implementation.

MDA is not limited to Meta Data Aspects (A) or Design and Architectural Models (B) alone, nor is it primarily about deriving models from Artificial Intelligence Systems (D). Instead, it provides a comprehensive framework that facilitates the creation of software systems by bridging the gap between business requirements and technology solutions.

References:

• An MDA Approach Based on UML and ODM Standards to Support Big Data Analytics1
• Improving Automatic UML2 Profile Generation for MDA Industrial Development2
• Applying 4+1 View Architecture with UML 2

In UML, a stereotype is a mechanism that extends the vocabulary of the UML in order to create new model elements. The given profile fragment defines a stereotype «architecture decision» that extends the metaclassClass. This stereotype includes three properties: Complexity, Risk, and Status, each typed by specific enumerations: Rank and Status. When a stereotype is applied to a UML element, it does not create physical attributes on the element; instead, it enables the element to carry additional information as specified by the stereotype — in this case, as Stereotype Properties. These properties are effectively tagged values that are associated with the stereotyped element. Hence, when a class is stereotyped as an «architecture decision», it will have the ability to hold values for Complexity, Risk, and Status according to the types defined bythe enumerations in the profile. This is consistent with the rules defined in the UML 2.x Superstructure Specification for profiles and stereotypes.

Given that the system is inStateA1, the sequence of triggers that will move the system toStateCmust take into account the transitions and their associated triggers as defined in the UML state diagram. Starting fromStateA1, the triggera5will cause a transition withinStateA, followed bya6, which moves toStateA2. The triggera5is not relevant as it is an internal transition inStateA1. Then,a3(the exit action forStateA) anda2would be followed to leaveStateAaltogether. Once out ofStateA,a1is used to transition toStateB, wherea10is an entry action, not a trigger. Finally, to get fromStateBtoStateC, the triggersa11followed bya12are needed. This sequence of triggers reflects the correct usage of exit, entry, and transition triggers as defined by UML state machine semantics.

The answer is B, "The transmitted object may be copied and the object identity may be changed." When an object is sent from one action to another, it is not always guaranteed that the identity of the object will be preserved. It depends on the semantics of the transmission, which may allow for object copying, and hence the object identity may change during the process.

References:

• UML 2.5 Specification: The section on send actions within activity diagrams describes the behavior of object flows, including transmission semantics regarding object identity and copying.

The value of Essential MOF (EMOF) lies in its ability to provide a straightforward framework for mapping MOF models to implementations such as XML Metadata Interchange (XMI) for simple metamodels2. This allows for easier integration and manipulation of MOF models in various platforms and tools.

In UML, operations can have preconditions defined, which are constraints that must be true before the operation is invoked. When an operation is redefined in a subclass, it is possible to add new preconditions or alter existing ones. Redefining an operation does not typically allow for changes to its scope or the addition of templates, but the preconditions may be expanded to reflect the semantics of the subclass. This is in line with the behavioral specification of operations in UML, where preconditions are part of the behavioral contract of an operation, as described in the UML 2.x Superstructure Specification.

In UML, a Dependency is a relationship that signifies that one NamedElement, the client, depends on another NamedElement, the supplier, meaning that a change in the supplier could affect the client. If NamedElement A is the supplier and NamedElement B is the client in a Dependency relationship, and there is a Comment indicating that both participate in a transformation, the interpretation is that B (the client) depends on A (the supplier) for that transformation. The comment does not necessarily change the nature of the Dependency relationship; it simply adds additional information about the nature of their interaction. A transformation could mean that B transforms A's supplied element in some way, but in terms of UML Dependency relationships,it would still be interpreted as "A depends on B" or "B requires A for its transformation". This interpretation aligns with the UML 2.x Infrastructure and Superstructure specifications, which explain Dependencies and their meanings within the UML metamodel.

For question number 50, the correct answer is C: Control tokens are offered on the outgoing Control Flows of the ExceptionHandler. According to the UML 2.5 specification, when an Exception Handler completes its execution, it does not halt the execution of the thread or retain control tokens internally; instead, it passes control tokens along the outgoing Control Flows. This behavior allows the activity to continue processing other behaviors or activities, based on the exception handling outcome.

References:

• UML 2.5 Specification: Provides a detailed description of the behavior of Exception Handlers within activity diagrams, including how control tokens are managed upon the completion of an exception handling sequence.

In UML, an InformationItem represents an abstraction of all those elements in a UML model that have an information-bearing feature. It is depicted as a classifier with the keyword «informationItem». An InformationItem does not have direct instances and serves as a mechanism to handle unspecified, untyped information in a model. In the context of a commercial transaction model, currencies such as euros, pesos, and dollars can be abstractly represented as InformationItems to signify that they are used as a form of data exchange but without specifying the concrete structure or data type. Figure 2 correctly uses InformationItem notation, with the «informationItem» keyword and the directed association pointing from the Currency InformationItem to the Euro, Peso, and Dollar, which are likely representations or manifestations of the Currency. This complies with the UML specification for representing abstract entities in models that are involved in the exchange or flow of information.

A minimal reflexive metamodel is a metamodel that is expressed using itself, meaning it can be used to describe its own structure and semantics. This concept is akin to a self-describing system. In the domain of metamodeling, this allows for a consistent and coherent definition of the metamodel that is both the subject and the tool of its own description2. This reflexivity is a key property that enables the metamodel to be used in a variety of contexts, ensuring that it remains consistent with its own definitions.

In UML, the{subsets}keyword is used to indicate that one property is a subset of another property. In the provided diagram fragment, the association end-b {subsets part}indicates that the propertybon classAis a subset of the propertyparton classB. This means that the elements associated withAthroughbare contained within the larger set associated withBthroughpart. This kind of relationship is typically used in more complex class models where a part-whole hierarchy is represented, and it allows the model to show that certain associations are more specific subsets of a more general association. This usage is explained in the UML 2.x Superstructure Specification, where the semantics of association subsets are defined.

The diagram depictsElectronic Device Kindas a class that requires a set of Certifications (required : Certification[1..*]). This implies that any subclass ofElectronic Device Kindmust provide a set of required Certifications because the multiplicity[1..*]indicates that at least one Certification is mandatory for each instance ofElectronic Device Kindor its subclasses. Therefore, when a subclass is created, it inherits the requirement to specify what Certifications are needed. This is a standard UML generalization, where the subclass inherits the attributes and constraints of its superclass. This interpretation is consistent with the rules defined in the UML 2.x Superstructure Specification, which includes the semantics of class generalization and attribute inheritance.

The reason for fUML to be compact is to facilitate the definition of clear semantics. A smaller, more focused subset of UML allows for a more precise and unambiguous specification of the execution semantics. This clarity is essential for ensuring that models are executed consistently and as intended across different tools and platforms2. The compact nature of fUML helps inachieving this goal by limiting the scope to the essential elements necessary for execution, thereby reducing complexity and potential for misinterpretation.

In UML, profiles are applied to specific model elements to adapt the UML metamodel to different domains or platforms. The provided diagram shows a UML package diagram within which the «Versioning» profile is applied to the "Business Logic" package, and the «DBProfile» is applied to the "Data" package. This is a correct use of profiles in UML as they allow the customization of parts of a model by applying additional constraints and stereotypes to specific packages or classes. There is no restriction in UML that a profile cannot be applied to multiple packages in the model simultaneously, and profiles do not necessarily need to be members of the namespace of the model they are applied to; they can be defined externally. Therefore, the scenario presented is a correct application of two different profiles to two distinct packages within the same model, conforming to the UML 2.x Superstructure Specification.