Chapter 2: عمليات البرمجيات

Chapter 2: Software Processes

• Software processes are a structured set of activities to develop a software system.
• Key activities include: specification, design and implementation (software development), validation, and evolution.
• Software process models provide abstract representations of a process, offering a particular perspective.
• Several software process models exist, including the waterfall model, incremental development, and integration and configuration.

Software Process Models

• Waterfall model: A plan-driven model with distinct phases (requirements definition, system and software design, implementation and unit testing, integration and system testing, operation and maintenance). It's inflexible and difficult to accommodate changes after the process begins. Best for projects with well-understood and stable requirements.
• Incremental development: Interleaves specification, development, and validation. Delivering functional increments iteratively. Easier to handle changing requirements. However, system structure can degrade with each increment without refactoring.
• Integration and configuration: Building systems from existing components (Commercial-off-the-shelf or COTS). Ideal for many business applications.

Key Process Stages

• Requirements specification: Establishes what services are required and constraints. Activities include elicitation and analysis, specification, and validation.
• Software design and implementation: Converts system specification into an executable system. Includes architectural design, interface design, component design, database design, and implementation.
• Software validation: Checks if the system conforms to its specification and meets users' needs. Involves testing: component testing, system testing, acceptance testing.
• Software evolution: The ongoing adaptation and improvement of a software system to align with changing needs and requirements.

Coping with Change

• Change is inevitable in large software projects.
• Changes may affect requirements, technologies, or platforms, necessitating adaptation.
• Techniques for adapting include anticipating change, tolerating it, through prototyping or incremental delivery, which allows for feedback and adjustments.

Software Prototyping

• Prototypes are initial versions of a software system. Used to demonstrate concepts and try out ideas.
• Evolutionary prototyping is an iterative model that builds upon prior prototypes.
• Throwaway prototyping prototypes are discarded after development, mainly due to its possible non-functional deficiencies. Benefits of prototyping include improved system usability, closer match to user needs, improved design quality, improved maintainability, and reduced development efforts.

Process Improvement

• Many companies utilize software process improvement to enhance software quality, reduce costs, and accelerate development.
• Process improvement involves identifying and executing changes to increase product quality and reduce development time.
• Key approaches to improvement include maturity models (e.g., SEI's capability maturity model), and agile methodologies.
• Effective process management emphasizes quantitative measurement to assess and refine procedures.

Incremental Delivery

• Focuses on delivering increments of functionalities to users.
• User feedback and prioritization of functionalities help to adapt to changing requests.
• The approach also helps to mitigate risk associated with complete system implementation by limiting the extent of any failure or malfunction.

Process Activities

• Real processes combine technical, collaborative, and managerial activities focused on defining, designing, implementing, and testing a software system.
• Specification, development, validation, and evolution activities are organized differently depending upon the chosen process model (e.g., waterfall vs. incremental).

تتناول هذه الوحدة الثانية عمليات البرمجيات كإطار منظم لتطوير أنظمة البرمجيات. تشمل الأنشطة الرئيسية: الت specification، التصميم والتنفيذ، التحقق، والتطور. كما تركز على نماذج عمليات البرمجيات المختلفة مثل نموذج الشلال والتطوير التكراري.