Podcast
Questions and Answers
What is one of the primary goals of refactoring a program?
What is one of the primary goals of refactoring a program?
Which factor is NOT typically associated with the cost of reengineering?
Which factor is NOT typically associated with the cost of reengineering?
What does data reengineering primarily involve?
What does data reengineering primarily involve?
Which option best describes the role of expert staff in the reengineering process?
Which option best describes the role of expert staff in the reengineering process?
Signup and view all the answers
Which of the following practices contributes to preventing future software degradation?
Which of the following practices contributes to preventing future software degradation?
Signup and view all the answers
What is the impact of separating maintenance and development teams on software maintainability?
What is the impact of separating maintenance and development teams on software maintainability?
Signup and view all the answers
Which of the following is NOT a reason why maintenance work has a poor image among software engineers?
Which of the following is NOT a reason why maintenance work has a poor image among software engineers?
Signup and view all the answers
What is primarily responsible for the increased difficulty in changing programs as they age?
What is primarily responsible for the increased difficulty in changing programs as they age?
Signup and view all the answers
Which approach is LEAST likely to reduce maintenance costs?
Which approach is LEAST likely to reduce maintenance costs?
Signup and view all the answers
Why is it often more expensive to add new features during maintenance compared to during development?
Why is it often more expensive to add new features during maintenance compared to during development?
Signup and view all the answers
Which statement best reflects a common issue faced by teams involved in software maintenance?
Which statement best reflects a common issue faced by teams involved in software maintenance?
Signup and view all the answers
What is a significant drawback of poor maintenance practices?
What is a significant drawback of poor maintenance practices?
Signup and view all the answers
Which technique is most effective in controlling maintenance costs?
Which technique is most effective in controlling maintenance costs?
Signup and view all the answers
What is a consequence of maintenance increasing program complexity?
What is a consequence of maintenance increasing program complexity?
Signup and view all the answers
Which statement accurately describes the Spiral model in software evolution?
Which statement accurately describes the Spiral model in software evolution?
Signup and view all the answers
What does the servicing stage in software evolution involve?
What does the servicing stage in software evolution involve?
Signup and view all the answers
What occurs during the phase-out stage of software evolution?
What occurs during the phase-out stage of software evolution?
Signup and view all the answers
When might a customer take over software support and evolution in-house?
When might a customer take over software support and evolution in-house?
Signup and view all the answers
What is the primary characteristic of software retirement?
What is the primary characteristic of software retirement?
Signup and view all the answers
What challenge is associated with using a separate company for servicing in software evolution?
What challenge is associated with using a separate company for servicing in software evolution?
Signup and view all the answers
In what scenario may a company consider a replacement for their software?
In what scenario may a company consider a replacement for their software?
Signup and view all the answers
What primary risk is associated with urgent change requests in software development?
What primary risk is associated with urgent change requests in software development?
Signup and view all the answers
What is a fundamental characteristic of agile methods regarding the evolution of software?
What is a fundamental characteristic of agile methods regarding the evolution of software?
Signup and view all the answers
What consequence may arise from making quick fixes in code without subsequent refactoring?
What consequence may arise from making quick fixes in code without subsequent refactoring?
Signup and view all the answers
What challenge can arise when a development team uses an agile approach but the evolution team prefers a plan-based approach?
What challenge can arise when a development team uses an agile approach but the evolution team prefers a plan-based approach?
Signup and view all the answers
What role do TDD and automated regression testing play in agile software evolution?
What role do TDD and automated regression testing play in agile software evolution?
Signup and view all the answers
Which statement best describes the relationship between development and evolution in agile methods?
Which statement best describes the relationship between development and evolution in agile methods?
Signup and view all the answers
What issue can arise from the evolution team's preference for agile methods if development was based on a plan-based approach?
What issue can arise from the evolution team's preference for agile methods if development was based on a plan-based approach?
Signup and view all the answers
What might be a potential drawback of frequent system releases in agile methods?
What might be a potential drawback of frequent system releases in agile methods?
Signup and view all the answers
What can be a consequence of not realigning system documentation and code during evolution?
What can be a consequence of not realigning system documentation and code during evolution?
Signup and view all the answers
What is one of the reasons maintenance costs can be significantly higher than development costs?
What is one of the reasons maintenance costs can be significantly higher than development costs?
Signup and view all the answers
Which of the following describes a potential consequence of continuous software maintenance?
Which of the following describes a potential consequence of continuous software maintenance?
Signup and view all the answers
What is a core aspect of software reengineering?
What is a core aspect of software reengineering?
Signup and view all the answers
Which of the following strategies can help mitigate high maintenance costs of aging software?
Which of the following strategies can help mitigate high maintenance costs of aging software?
Signup and view all the answers
Which of the following is not part of the software reengineering process?
Which of the following is not part of the software reengineering process?
Signup and view all the answers
Why should maintenance be given as high a status as new software development?
Why should maintenance be given as high a status as new software development?
Signup and view all the answers
What is a crucial aspect to consider when integrating development and maintenance?
What is a crucial aspect to consider when integrating development and maintenance?
Signup and view all the answers
What is a possible drawback of choosing to avoid major changes in system architecture?
What is a possible drawback of choosing to avoid major changes in system architecture?
Signup and view all the answers
What can be a long-term solution for managing maintenance challenges in software?
What can be a long-term solution for managing maintenance challenges in software?
Signup and view all the answers
What is an important factor contributing to maintenance difficulties of older legacy systems?
What is an important factor contributing to maintenance difficulties of older legacy systems?
Signup and view all the answers
Study Notes
Software Evolution
- Software systems have long lifecycles, requiring continuous adaptation and evolution.
- Change is inherent due to new requirements, changing business environments, error correction, and hardware/software upgrades.
- Software systems must adapt throughout their lifetime, from deployment to retirement.
- A major challenge for organizations is effectively managing these changes to existing software systems.
Importance of Evolution
- Organizations heavily invest in software systems, viewing them as critical business assets.
- Maintaining the value of these assets necessitates updates and modifications.
- A significant portion of the software budget, often 60-90%, is devoted to modifying existing software rather than developing new systems.
- Approximately 75% of the development workforce in the US is involved in software evolution.
A Spiral Model of Development and Evolution
- Illustrates an iterative approach to development and evolution.
- The model incorporates stages like specification, implementation, validation, and operation, repeating in a spiral pattern to progressively refine the system.
- Represents a cyclical process to manage change and evolution.
- Progresses from release 1 through 3, iteratively.
Software Evolution Models
- Spiral model is appropriate when the same company handles the software's entire lifetime. This facilitates seamless transitions from development to evolution.
- Custom software often follows different models where the customer may directly support or contract another company.
- Discontinuities in evolution processes may occur due to factors like requirements and design document issues.
- Companies merging or reorganizing may inherit software from other companies.
Software Evolution Life Cycle for Business
- Evolution: The operational phase of continuous software development where new requirements are incorporated, and the software adapts.
- Servicing: Software modification with only essential bug fixes, without adding new features. No further development in this phase.
- Retirement: Removal of software from ongoing use. Significant cost associated for system replacement and data migration.
Evolution Processes
- No single, standardized evolution process exists.
- The evolution process depends on various factors: the specific software, development methodologies, and personnel expertise.
- Proposals for change (new requirements, bug reports, improvements) trigger evolution.
- Changes are linked to affected components for cost and impact assessment.
- Change identification, evaluation, and evolution continue throughout the system's lifecycle. An iterative process.
Change Identification and Evolution Processes
- Iterative process where system revisions are meticulously planned, implemented, and rigorously tested.
- Program understanding is crucial, especially when original developers are not involved in the change implementation.
- Updated specifications and design documents are essential to reflect the changes.
Change Implementation
- Iterative process of implementing changes within the development lifecycle. This is critical due to the fact that the first stage can entail understanding the original system's functionality, especially when developers were not involved in the change implementation.
- Specifications and design documents are updated to align with the changes.
Urgent Change Requests
- Urgent changes necessitate deviations from the regular software engineering process.
- These changes may arise in response to system faults, environmental updates, or critical business demands.
- Addressing urgent changes may require bypassing standard processes to ensure timely resolution.
Agile Methods and Evolution
- Agile development inherently aligns well with evolutionary development.
- Evolution is seamlessly integrated into the ongoing development process.
- Changes are often expressed as new user stories, which drive incremental adjustments.
- Test-driven development (TDD) and automated regression tests are valuable for managing evolving systems.
Handover Problems
- Challenges arise when development and evolution teams use different methodologies.
- Difficulties arise when evolution teams are unfamiliar with agile methodologies, and vice-versa.
- Lack of documentation may cause challenges when expected.
- Difficulties arise in transitioning from planned or process-driven approaches to agile or iterative approaches.
Software Maintenance
- Modifying software after deployment, often custom software.
- Evolution differs slightly from maintenance, which focuses on continuous updates without a formal new release.
- Maintaining existing systems typically does not mandate extensive architectural changes or significant overhaul.
Types of Maintenance
- Fault repairs: Addressing defects and fixing bugs.
- Environmental adaptations: Tailoring the software to new operating environments.
- Function addition/modification: Enhancing existing functionality to meet changed requirements.
Maintenance Effort Distribution
- Diagram illustrating the relative contribution of different maintenance tasks, categorized into fault repair, environmental adaptation, and functionality modifications. (Diagram not available).
Maintenance Costs
- Maintenance costs often exceed development costs, typically 2-100 times higher depending on the application.
- Significant increases as software age, due to increasing difficulty in making changes to existing codebases, and increasing complexity of the system, due to adding additional features and code over time.
- Costs influenced by technical and non-technical factors.
Software Reengineering
- Method for improving legacy systems' structure and comprehension.
- Minimizes changes to functionality while modernizing system architecture.
Reengineering Process Activities
- Source code translation: Converting source code to a modern language.
- Reverse engineering: Analyzing existing code for documentation and design understanding.
- Program structure improvements: Reorganizing code to enhance clarity.
- Program modularization: Grouping related code into independent modules.
- Data reengineering: Restructuring data to improve efficiency and organization.
Reengineering Cost
- Reengineering expenses correlate to the modification scope.
- Source code translation is the most economical option.
- Architectural refactoring proves the most expensive option.
Refactoring
- Continuous process to enhance code readability and maintainability.
- Focused on enhancing existing code without introducing new functionality.
- Aims to address structural complexity without compromising program logic.
'Bad Smells' in Program Code
- Common code design flaws ('bad smells') that indicate opportunities for improvement.
- Duplicate code: Identical code blocks, indicating potential for consolidation.
- Long methods: Excessive method length, often suggesting modularization.
- Switch statements: Extensive use of switches, indicative of potential polymorphism improvement.
- Data clumping: Tight coupling of related data areas, suggesting refactoring into independent entities.
- Speculative generality: Overly general code anticipating future requirements, potentially unnecessary complications.
Key Points
- Software development and evolution can be treated as an integrated cycle.
- Custom software maintenance costs tend to far exceed initial development costs.
- Software evolution typically responds to change requests and includes stages like change impact analysis and implementation.
- Software reengineering targets system restructuring, addressing challenges in older systems, aiming to enhance readability and maintainability.
- Refactoring is a vital technique to improve code structure without altering system functionality.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Explore the challenges and strategies involved in the evolution of software systems. This quiz covers the lifecycle of software, the importance of continuous adaptation, and the allocation of resources towards software modifications. Understand how organizations manage change in their critical software assets.
