CPSA-FL ISAQB Certified Professional for Software Architecture -Foundation Level Questions and Answers

The purpose of defining the system context includes:

• To illustrate the system’s interfaces with external systems (B) - True
• To clarify the area of responsibility of the software architect C - True
• To represent the external systems (D) - True
• To distinguish between infrastructure and application (E) - True
• To distinguish between the hardware and software of a solution (F) - True

Defining the system context is a crucial step in software architecture as it helps to establish the boundaries and interactions of a system within its environment. Here’s a detailed explanation of the purposes:

• To Illustrate the System’s Interfaces with External Systems (B): It is essential to understand how the system interacts with other systems, which can influence requirements and design1.
• To Clarify the Area of Responsibility of the Software Architect ©: By defining the system context, the architect’s responsibilities regarding the system’s interactions and boundaries are made clear1.
• To Represent the External Systems (D): The system context helps identify and represent all external entities that interact with the system, which is important for comprehensive design and analysis1.
• To Distinguish Between Infrastructure and Application (E): Understanding the system context allows for a clear distinction between the infrastructure (the environment in which the application operates) and the application itself1.
• To Distinguish Between the Hardware and Software of a Solution (F): The system context helps to differentiate between the hardware components and the software components of a system, which is vital for system integration and deployment1.

These aspects of the system context are fundamental for ensuring that the system is designed and developed to meet its intended goals and operate effectively within its designated environment.

References:

• Smartpedia article on System Context1.
• Visual Paradigm Blog on System Context Diagrams2.
• microTOOL article on System Context3.

In template-based architecture documentation, the most important fields are:A. To describe module structures (white boxes) - This involves detailing the internal structure of modules, which is crucial for understanding how software components are implemented and how they interact internally.B. To describe individual architectural modules and their external interfaces (black boxes) - This focuses on the interfaces and interactions of modules with external components, essential for understanding system integrations and dependencies.D. To use a standardized document structure - Standardization in documentation facilitates consistency, readability, and maintainability of documents, which is critical for long-term project management and new team member onboarding.

A) FalseB) FalseC) TrueD) TrueE) TrueF) True

A) Agile approaches make written documentation unnecessary. In such cases, verbal communication can substitute for documentation.

• False. Even in agile approaches, written documentation is important for maintaining a clear and consistent understanding of the architecture among team members and stakeholders1.

B) Written documentation makes verbal reiteration unnecessary.

• False. Verbal communication is essential for clarifying and reinforcing the content of written documentation, especially when addressing complex or nuanced architectural issues2.

C) Despite written documentation, verbal communication of architectural interrelationships is important.

• True. Verbal communication plays a crucial role in explaining the rationale behind architectural decisions and interrelationships that may not be fully captured in documentation2.

D) Documentation and communication should use identical terms and rationale.

• True. Consistency in terminology and rationale between documentation and verbal communication helps prevent misunderstandings and ensures that all parties have a common understanding of the architecture2.

E) Documentation should be created primarily for project participants who either cannot or do not want to read the system’s source code.

• True. Documentation serves as a guide for those who may not be directly involved in coding but need to understand the architecture, such as managers, new team members, or external stakeholders2.

F) Communication and documentation complement each other: verbal communication helps architects determine what must be recorded in writing.

• True. Verbal communication often reveals what aspects of the architecture are most important or confusing to team members, guiding what should be emphasized in written documentation

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.

Designing effective interfaces is critical in software architecture, ensuring that they are both usable and robust. The characteristics that generally make interfaces more desirable include:

• A: Easy to extend - An interface should be designed such that it can be extended without breaking existing implementations. This characteristic is important for maintaining backward compatibility while allowing for future growth and changes in requirements.
• C: Clear descriptions of assertions and prerequisites - Interfaces should clearly specify what is required of the caller (prerequisites) and what the interface guarantees in return (assertions). This clarity is vital for ensuring that the interface is used correctly.
• G: Hard to misuse - An interface should be designed in such a way that there is little room for incorrect usage by the client. This involves making the interface intuitive and minimizing the potential for errors, which improves the robustness and reliability of the software system.

These characteristics help in creating interfaces that are not only functional but also robust, maintainable, and adaptable to future needs, aligning with best practices in software architecture.

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.

The techniques best suited to illustrate the interaction of runtime building blocks are:A. Activity diagrams - Useful for showing the flow of control among various activities and decisions in the system.B. Sequence diagrams - Ideal for depicting the order of messages exchanged between components or objects in a specific scenario.C. State diagram - Shows how a component or an object changes its state in response to events, highlighting dynamic behavior.G. Depiction of screen flows (sequence of user interactions) - Useful for visualizing the sequence of user interactions with the system, which is critical for user-centric design and runtime behavior analysis.

A) FalseB) FalseC) FalseD) TrueE) TrueF) False

Postel’s law, also known as the robustness principle, is a guideline in software engineering that advises to "be conservative in what you do, be liberal in what you accept from others"1. This principle has implications for system design and interaction with external interfaces:

A) Response time of the system is reduced: This is false. Postel’s law does not directly relate to the response time of a system1.

B) Implementation effort increases: This is false. Being liberal in what is accepted can actually simplify implementation because the system is designed to handle a wider range of inputs without failure1.

C) Usability of the system is reduced: This is false. Postel’s law aims to increase robustness and interoperability, which can enhance usability by making the system more resilient and accommodating1.

D) Robustness of the system is increased: This is true. By being conservative in outputs and liberal in inputs, the system becomes more robust, handling a variety of inputs without error1.

E) The integrity of the data transferred via interfaces is increased: This is true. Accepting a wide range of inputs and adhering strictly to output specifications helps maintain data integrity across different systems1.

F) Availability of the system is reduced due to potentially bad quality of input data: This is false. Postel’s law suggests that the system should be designed to handle poor quality input data gracefully, thus maintaining availability1.

Applying Postel’s law helps create systems that are more tolerant of input variations and strict in their outputs, contributing to overall system robustness and reliability1.

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.