CPSA-FL Sample Questions Answers

The performance of a system often competes with its:

• Flexibility (A) - True1
• Memory usage (B) - True1
• On-time completion of the project C - False
• Adaptability (D) - True1
• Usability (E) - True1
• Security (F) - True1
• Testability (G) - True

In system design, performance trade-offs are a critical consideration. Here’s an explanation of how each listed aspect competes with system performance:

• Flexibility (A): Systems designed for high performance may be less flexible because they are optimized for specific tasks or conditions1.
• Memory Usage (B): High-performance systems may require more memory to store data and instructions for rapid access, which can be at odds with limited memory resources1.
• On-time Completion of the Project ©: While performance considerations can impact project timelines, they do not inherently compete with the on-time completion of a project.
• Adaptability (D): Systems that need to perform well under varying conditions may sacrifice adaptability, as they are tightly coupled with their performance optimizations1.
• Usability (E): Sometimes, the pursuit of performance can lead to complex user interfaces or workflows, affecting usability negatively1.
• Security (F): Security measures can introduce additional processing and checks, potentially slowing down system performance1.
• Testability (G): High-performance systems may be harder to test due to their complexity and the need for specialized testing environments or tools1.

These trade-offs highlight the importance of balancing different system attributes to meet the overall goals and constraints of a project.

References:

• CodingDrills article on Trade-Offs in System Design1

The correct statements about data structures, specifically stacks, are:A. The push operation usually places a new element onto a stack. - This is the basic operation of a stack data structure, where elements are added to the top of the stack.D. A stack usually only provides access to one element at a time. - In stack terminology, this is known as LIFO (Last In, First Out) behavior, where only the top element is accessible at any time for operations like pop or peek.

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.

To evaluate the reliability of a software system effectively, two methods stand out:B. Measurement of ‘Mean-Time-between-Failure’ (MTBF) - This is a standard measure of system reliability and is crucial for determining the average time between failures, helping to predict system reliability over time.E. Conducting an ATAM evaluation - Architecture Tradeoff Analysis Method (ATAM) provides a structured approach for evaluating decisions involving high-stake tradeoffs in software architectures, particularly affecting reliability among other quality attributes.

A) TrueB) TrueC) FalseD) TrueE) TrueF) True

A) Top-down and bottom-up design may be employed in the same project.

• Top-down and bottom-up are two approaches to the design of software architecture. In top-down, the high-level design is created first, focusing on general functionalities and structure. In contrast, bottom-up starts with detailed designs focusing on a component or module level.

A) TrueB) FalseC) TrueD) True

A) The project plan from management is influenced by architectural decisions.

• True. Architectural decisions often have significant implications on the project plan, including timelines, resource allocation, and technical approaches1.

B) Cost estimates are primarily the responsibility of the architect.

• False. While architects may contribute to cost estimates, especially regarding design-related expenses, it is typically the management’s responsibility to oversee and finalize cost estimates for the entire project2.

C) Architects advise project management on the definition of work packages.

• True. Architects play a crucial role in defining work packages, particularly in ensuring that the technical aspects of the project are accurately captured and planned for1.

D) Management and architects cooperate on handling of technical risks.

• True. Both management and architects need to work closely to identify, assess, and manage technical risks throughout the project2.

The interpretations of Conway’s law that are true and false are as follows:

• True:
• False:

Conway’s law suggests that the structure of systems designed by an organization will mimic the communication structures of that organization1. This means that the way teams are organized and communicate will influence the design of the software they are developing. Here’s an explanation of each interpretation:

• True Statements:
• False Statements:

Conway’s law is a valuable consideration in software engineering, reminding us that organizational decisions can have a significant impact on the design and functionality of the software.

References:

• Wikipedia article on Conway’s law1.
• ThinkingLabs article on Shades of Conway’s Law2.
• Dovetail article on What Is Conway’s Law

Iterative and incremental design methods are fundamental in software development, allowing for flexibility, better risk management, and focused delivery of functional components.

• A: Iterations involve repeated cycles of design, development, and testing, which help manage and resolve uncertainties as more knowledge is gained throughout the project lifecycle.
• B: The iterative process facilitates early detection of design and integration issues, as feedback can be incorporated promptly to refine the system progressively.
• F: Incremental design focuses on delivering functional increments of the product, ensuring that key functionalities are developed and delivered in priority order, allowing for early testing and refinement.