CPSA-FL Questions and Answers

For a building block, the characteristics visible only in the whitebox view are:

• Code structure of the building block (D)
• Algorithms used in the building block (E)
• Implementation details for the security requirements of the building blocks (G)

The blackbox view suffices for:

• Public interfaces of the building block (A)
• Test coverage based on unit tests for sub building blocks contained in the building block (B)
• Test coverage based on integration tests ©
• Security requirements of the building blocks (F)

In software architecture, the whitebox view reveals the internal workings of a building block, including its code structure, algorithms, and specific implementation details1. This view is essential when the internal structure and behavior of the component need to be understood or modified.

On the other hand, the blackbox view treats the building block as an opaque entity, focusing on its exposed interfaces and observable behaviors without revealing its internal structure2. This view is sufficient for understanding what the building block does from an external perspective, such as its public interfaces and how well it performs its functions as determined by testing.

Here’s a breakdown of the characteristics:

• Whitebox View:
• Blackbox View:

References:

• arc42 Documentation on Building Block View1.
• Stack Overflow discussion on the difference between black box and white box in component diagrams2.
• Flylib Section on Black-Box and White-Box Component Views3.

As an architect, you can specify the following characteristics of a black-box building block:

• Compliance with functional requirements (A)
• Compliance with non-functional requirements (B)
• Purpose and/or responsibility (D)
• Method signature of public interfaces (E)
• Data formats of public interfaces (F)

In software architecture, a black-box building block is a component whose internal structure is not exposed to or understood by other components. It is defined only by its provided functionality and the services it offers. Here’s a detailed explanation of each characteristic:

• Compliance with Functional Requirements (A): This refers to the ability of the building block to perform the functions it was designed to do, which are often captured in a functional specification document.
• Compliance with Non-functional Requirements (B): These are criteria that can be used to judge the operation of a system, rather than specific behaviors. This includes requirements related to scalability, performance, security, and reliability.
• Purpose and/or Responsibility (D): This defines the role the building block plays in the overall system architecture, including its responsibilities and the services it provides.
• Method Signature of Public Interfaces (E): The method signature defines the interface that other components can use to interact with the building block. It includes the method name, parameters, and return type.
• Data Formats of Public Interfaces (F): This specifies the format and structure of the data that is accepted or returned by the building block’s public interfaces.

These characteristics are essential for ensuring that the building block can be effectively integrated into a larger system and interact with other components as expected.

References:

• Bass, L., Clements, P., & Kazman, R. (2012). Software Architecture in Practice (3rd ed.). Addison-Wesley Professional.
• Martin, R. C. (2003). Agile Software Development: Principles, Patterns, and Practices. Prentice Hall.
• Fowler, M. (2002). Patterns of Enterprise Application Architecture. Addison-Wesley.

A) FalseB) TrueC) TrueD) False

A) Architectural objectives and project objectives need to be identical.

• This is false. Architectural objectives are concerned with the technical goals and quality attributes of the system, while project objectives are broader and include timelines, budgets, and overall project deliverables12.

B) Most of the time, architectural objectives are of a more long-term nature than project objectives.

• This is true. Architectural objectives often focus on the sustainability and maintainability of the system, which are long-term considerations, whereas project objectives may be more immediate and focused on the project’s completion12.

C) Architectural objectives and project objectives need to be negotiated between the concerned parties.

• True. Both sets of objectives should align with the stakeholders’ needs and the project’s overall goals, and thus require negotiation to ensure that all parties’ interests are addressed3.

D) Architectural objectives are a subset of project objectives.

• This is false. Architectural objectives are not necessarily a subset but are related and should support the project objectives. They deal specifically with the architecture of the system, which is one aspect of the project

The correct statements about design patterns are:A. Design patterns are not invented but discovered. - Design patterns represent solutions to common design problems and are derived from repeated experiences and observations in software development rather than being invented.B. Design patterns should always be described alongside the problem they are supposed to solve. - A fundamental aspect of using design patterns is understanding the specific problem a pattern addresses, which helps in applying the pattern effectively in relevant scenarios.

The white-box view of a software building block provides an in-depth perspective on the internal structure and behavior of the building block.

• A: The dependencies of the internal building blocks of 'foo' are crucial for understanding how changes in one part affect others and for managing future modifications.
• C: The algorithms of the internal building blocks of 'foo' give insight into the logic and operations performed within the block, which is essential for performance analysis and optimization.
• D: The internal building blocks of 'foo' describe the finer-grained components or modules within 'foo', detailing their responsibilities and interactions, fundamental for detailed design and implementation.

A) TrueB) TrueC) TrueD) TrueE) TrueF) TrueG) True

When choosing a software-architecture modeling tool, several factors can play a role:

A) Multi-user capability is important for collaborative environments where multiple architects work on the same model simultaneously1.

B) Support of UML 2.x and SysML ensures that the tool can handle widely-used modeling languages for software and systems engineering1.

C) Document generation is a key feature that allows for the automatic creation of documentation from the model1.

D) Support of model transformations in preparation of the code generation indicates the tool’s ability to convert models into other forms or even into executable code1.

E) Support of code generation can significantly speed up the development process by generating code from the models1.

F) Compliance with standards ensures that the tool adheres to industry standards, which can be crucial for interoperability and future-proofing1.

G) Purchase and licensing costs are practical considerations that affect the total cost of ownership of the tool1.

These criteria are aligned with the iSAQB® SOFTWARE ARCHITECTURE – FOUNDATION LEVEL documents, which emphasize the importance of these factors in the selection of a software-architecture modeling tool1.

When designing external interfaces, several considerations must be taken into account:A. Volatility of neighbouring systems - Changes in neighboring systems can affect the stability and compatibility of interfaces, requiring interfaces to be adaptable to changes.C. Protocols enforced by neighbouring systems - It's crucial to align with the protocols used by neighboring systems to ensure seamless communication and interoperability.D. Expected amount of parallel calls - This affects the scalability and performance requirements of the interface, as it must be designed to handle the expected load efficiently.