Why Study Software Engineering?

Why Study Software Engineering?

• A solid foundation in software engineering is essential in today's digital age for those working on web applications, mobile apps, enterprise systems, or embedded systems
• Prepares one to develop high-quality software meeting business and user needs
• Enables effective collaboration in cross-functional teams
• Provides adaptability to evolving technologies and methodologies
• Allows contribution to innovative solutions for real-world problems

Systems Analysis and Design (SAD)

• SAD is a structured approach used to develop information systems that address an organization's needs
• Understanding the problem domain, analyzing requirements, designing solutions, and documenting the process are key activities.
• This process documentation allows for future reference

System Analysis and Design Definition

• SAD involves either creating an information system or changing it so that it supports the people who use it and are affected by it
• SAD integrates ideas from computer science, engineering, and business to create systems that work well and efficiently

Key System Analysis and Design Concepts

• Information System: This system collects, processes, stores, and sends out data to provide information that is meaningful
• System Development Life Cycle (SDLC): SDLC defines the steps to build an information system which involves planning, analysis, design, implementation, and maintenance
• Objectives:
  • Developed systems must fulfill user needs
  • Resources (time, cost, and effort) should be used effectively
  • Systems should be high-quality, scalable, and easy to maintain

Importance of System Analysis and Design

• SAD aligns business goals with IT solutions
• SAD reduces risks in system development
• SAD provides a roadmap for project execution
• SAD facilitates communication between technical and non-technical stakeholders

System Planning Defined

• System planning occurs as the first SDLC stage
• System planning defines the scope and objectives of a project and involves the need for a new system or improvements to an existing one

Key Activities in System Planning

• Feasibility Study:
  • Determines technical, economic, and operational feasibility
  • Recommends the best alternative
• Project Scope Definition:
  • System boundaries (what it will and will not do) are defined
  • Identifies key stakeholders and their roles
• Resource Allocation:
  • Estimates time, budget, and personnel
  • Develops a project plan with milestones and deliverables
• Risk Assessment:
  • Identifies potential risks and mitigation strategies
  • Prioritizes risks by impact and likelihood

Output of System Planning

• Project charter or proposal outlining the goals, scope, and expected outcomes
• Feasibility report summarizes the analysis and recommendations

Definition of System Analysis

• Analysis involves gathering and interpreting user needs
• Analysis also helps to have a better understanding of what the system will be used for and setting functional requirement specifications for the system being developed

System Analysis Key Activities

• Requirement Gathering:
  • Uses interviews, surveys, and workshops with stakeholders
  • Tools such as use cases, user stories, and scenarios are utilized to capture the requirements
• Data Modeling:
  • Data flow diagrams (DFDs) visualize how data moves
  • Entity-relationship diagrams (ERDs) represent data structures
• Process Modeling:
  • Business processes are analyzed using flowcharts, activity diagrams, or BPMN (Business Process Model and Notation)
  • Inefficiencies are identified as well as Improvements
• Requirement Validation:
  • Requirements must be complete, consistent, and unambiguous
  • Obtain stakeholder sign-off to confirm agreement

System Analysis Output

• Requirements specification document details functional and non-functional requirements
• Data models and process models describe system structure and behavior

System Design Defined

• System design is where solutions are conceptualized, involving creating a system architecture blueprint, database design, user interface, and other components

Key Activities in System Design

• Architectural Design:
  • Choose architecture (e.g., client-server, microservices, cloud-based)
  • Define modules and their interactions
• Database Design:
  • Normalize data for efficiency and to eliminate redundancy
  • Design tables, relationships, and indexes based on ERD
• User Interface Design:
  • Develop wireframes and mockups to visualize the user interface
  • Ensure usability and accessibility standards
• Algorithm Design:
  • Write pseudocode or flowcharts for critical algorithms
  • Optimize performance and resource usage
• Technology Selection:
  • Choose programming languages, frameworks, and tools based on project requirements
  • Consider scalability, security, and maintainability

System Design Output

• Detailed design documents include architectural diagrams, database schemas, and UI prototypes
• Technical specifications for developers guide system implementation

System Documentation Defined

• System documentation records all aspects of the system, including design, functionality, and usage. It serves as a reference for developers, testers, and end-users

Types of System Documentation

• Technical Documentation:
  • Design Documents: Describes the system architecture, database design, and algorithms
  • API Documentation: details interfaces and endpoints.
  • Code Comments: Explains code segments
• User Documentation:
  • User Manuals: Guides users on operations
  • Help Files: Quick access to troubleshooting
  • Training Materials: Supports user training sessions
• Operational Documentation:
  • Installation Guides: Outlines deployment steps
  • Maintenance Manuals: provides update and repair instructions

System Documentation Best Practices

• Use clear and concise language
• Organize content logically and include visuals (diagrams, screenshots)
• Keep documentation up-to-date throughout the system lifecycle

Importance of System Documentation

• Facilitates knowledge transfer
• Ensures consistency and standardization
• Supports system maintenance and future enhancements

When to Use System Documentation

• Maintenance and Updates:
  • If a different team needs to maintain or update the system
• Long-Lived Solutions:
  • If the system is expected to last over a year
• Complex Systems:
  • If the system uses multiple components or integrations

How to Use System Documentation

• Identify the Audience:
  • Know who will use the documentation (developers, users, etc.)
• Understand Their Needs:
  • Engage stakeholders to know their information needs
• Plan Creation and Maintenance:
  • Decide when and how documentation will be created
• Choose a Repository:
  • Select a central, accessible location
• Keep It Up-to-Date:
  • Regularly review and update documentation

Caveats and Considerations for System Documentation

• Balance Effort and Value:
  • Avoid over-documenting, focus on what adds value
• Differentiate Between Project and System Documentation:
  • Project documentation is temporary, system documentation is permanent
• Adopt Lightweight Approaches:
  • Employ concise formats like "Given-When-Then" scenarios
• Leverage Tools:
  • Use tools like Confluence, Notion, or Git-based documentation systems
  • Automate generation of API documentation using Swagger

Software and System Testing Defined

• Testing ensures the software meets requirements, functions as intended, and is free from defects
• It involves evaluating system behavior under conditions to identify bugs, verify functionality, and validate performance.

Testing Methodologies Defined

• Structured approaches define testing activity planning, execution, and evaluation to ensure testing is systematic, repeatable, and aligned with project goals

Key Testing Methodologies

• Waterfall Model Testing:
  • Testing happens after each development phase (requirements, design, implementation)
  • Suitable for projects with clear needs, has changes that are difficult, and has limited flexibility
• Agile Testing:
  • Testing is integrated with feedback loops between developers, testers, and stakeholders
  • Focuses on continuous testing, improvement, collaboration, and adaptability
• V-Model Testing:
  • A Waterfall variation maps testing activities to development phases
  • Emphasizes early defect detection
• DevOps Testing:
  • Combines development, operations, and testing into a continuous cycle via automation
  • Focuses on Continuous Integration/Continuous Deployment (CI/CD) and automated testing
• Incremental Testing:
  • System is tested incrementally as modules are developed and integrated
  • Reduces risk by identifying early issues and being useful for modular architectures
• Spiral Testing:
  • Combines Waterfall and Agile, focusing on risk analysis at iterations
  • Suitable for complex, high-risk projects

Testing Techniques Defined

• Testing techniques are specific methods used to design and execute test cases to help make sure the system is fully tested and to improve how well the testing works

Types of Testing Techniques

• Black Box Testing:
  • Tests system functionality without knowledge of its internal code
  • Validates inputs, outputs, and functionality against requirements
  • Involves: Equivalence Partitioning which reduces test cases and Boundary Value Analysis that tests values at input ranges
• White Box Testing:
  • Tests internal logic and code structure with a focus on ensuring code correctness and identifying errors
  • Uses techniques such as statement coverage that every line of code is executed, branch coverage for all decision points, and path testing for all possible execution paths
• Gray Box Testing:
  • Combines elements of Black Box and White Box testing with partial knowledge of the system internals
  • Checks functionality while having some awareness of the system's internal workings
• Exploratory Testing:
  • Testers explore the system without predefined test cases for unexpected issues and usability
• Regression Testing:
  • Verifies recent changes have not introduced new defects while also ensuring existing functionality remains intact
• Performance Testing:
  • Evaluates the system's performance under certain conditions
  • Includes Load Testing which tests under expected conditions, Stress Testing that tests severe conditions, and Scalability Testing that tests the scale of the system
• Security Testing:
  • Identifies vulnerabilities and ensures data protection
  • Focuses on protection against threats such as SQL injection, cross-site scripting (XSS), and unauthorized access
• Usability Testing:
  • Evaluates the system's ease of use and user experience
  • Focuses on if the system is intuitive and meets user expectations

Testing Documentation Defined

• Testing documentation records the testing process and includes test plans, test cases, results, and reports to ensure that the testing process is thorough, keeps track of changes, and is reliable

Key Components of Testing Documentation

• Test Plan:
  • Outlines overall testing strategy, objectives, scope, and resources.
  • Details testing scope, objectives, milestones, schedules, roles/responsibilities, and risk analysis
• Test Cases:
  • Defines testing steps
  • Contains a Test Case ID, all preconditions, step instructions, the outcomes of what's expected, and the actual results
• Test Scripts:
  • Automates test cases using scripts or tools like Selenium, JUnit, and TestNG
• Test Logs:
  • Records the results for test cases and the details of issues encountered
• Defect Reports:
  • Documents what defects were found, how severe they are, and how to reproduce them, such as defect ID, related steps, severity,and the resolution status
• Test Summary Report:
  • Summarizes the complete conclusion summarizing the testing effort, results, and key findings

System Deployment and Integration Defined

• Critical phases in the Software Development Life Cycle (SDLC) are Deployment and integration
• SDLC ensures the transition of a system from development as seamless as possible
• These phases include the integration of diverse system components, deployment into operational environments, and documentation for future reference

System Integration

• System integration combines individual software pieces into a completed unified system that interacts correctly and meets overall system requirements

Key System Integration Methodologies

• Big Bang Integration:
  • All components are implemented at once
  • Is high risk and suitable for small systems with minimum dependencies
• Incremental Integration:
  • Integrated with one other component of smaller groups with tests after
  • Reduces risks, and is continuously improved on, while providing continual feedback
• Top-Down Integration:
  • Progressively integrates highest-level modules with lower-level ones
  • Useful with systems where high-level function is prioritized
• Bottom-Up Integration:
  • Progressively integrates lowest-level modules with higher-level ones and ensures the foundational components are stable.
• Sandwich Integration (Hybrid Approach):
  • Integrates top-down and bottom-up
  • Balances the advantages of both methodologies and reduces dependency on stubs and drivers
• Continuous Integration (CI):
  • Developers integrate code into a shared repository, triggering automated builds and tests, supporting collaboration and early detection of integration issues

System Integration Processes

• Requirement Analysis:
  • Understand the interfaces, interactions, and dependencies between components
• Design Integration Strategy:
  • methodology choice is based on the complexity as well as the risks
• Develop Integration Tests:
  • Test cases are created to validate component interaction
• Execute Integration:
  • Combine components and compatibility tests are done
• Resolve Issues:
  • Known defects are identified
• Validate End-to-End Functionality: -System-wide testing to ensure all components work properly

System Deployment Defined

• Deployment is the release of the system for end users and involves planning, preparation, execution, and monitoring to ensure a smooth transition

Key System Deployment Methodologies

• Big Bang Deployment:
  • A quick complete deployment of a new systems, however, it holds a large risk
• Phased Deployment:
  • A gradual deployment of features or modules that allows for feedback
• Parallel Deployment:
  • Both new and legacy system runs at the same time.
• Blue-Green Deployment:
  • Only 1 active environment at a time, the inactive environment is always updated
• Canary Deployment:
  • A deployment using only a handful a users for testing
• Rolling Deployment:
  • Incremental deployment across server to ensure availability

System Deployment Processes

• Preparation:
  • The deployment strategy is planned
• Build and Package:
  • Preparing to Deploy
• Deploy to Staging:
  • testing in a state like environment
• Execute Deployment:
  • Deployment to a production environment
• Post-Deployment Testing:
  • Testing and reviewing environment
• Monitor and Optimize:
  • Continuously checking performance

System Deployment and Integration Documentation Defined

• Documentation provides a historical record and accountability and traceability to keep track of the work that is being done

Key Components of Documentation

• Integration Plan:
  • How to strategically integrate the components
• Deployment Plan:
  • Defines strategy, schedule, and implementation
• Configuration Management:
  • Configuration settings
• Tools:
  • Configuration of software
• Test Report:
  • Results of integration
• Runbooks:
  • Step by step process of operation and maintenance
• Change Logs:
  • Track changes the were made during deployment

REST Defined

• REpresentational State Transfer is a design for networked applications that allows communication to be done between client and server apps using HTTP methods

REST Key Characteristics

• Stateless: Each request contains the servers needs
• Resource based: Data is organized with URLs
• Lightweight: Simple formats like JSON or XML

SIMPLE OBJECT ACCESS PROTOCOL Defined

• SOAP is an exchange between online services. Unlike REST, it is more strict

SOAP Key Characteristics

• Protocol Based: Strict rules can be followed
• Language Independent: Can be used in just about every language that supports XML

Why CRM?

• Stands for: Customer Relationship Management
• CRM: Improving customer relationships
• Key features: Analytics, customer information
• Salesforce : Software and other Examples

System Management Defined

• Encompasses activities and the best practices that involve monitoring performance, addressing issues, updating software in system lifecycle

Corrective Maintenance: Key Factors

• Purpose: The point of this maintenance is to fix errors in systems
• Process:
  • Identify through logs or user reports
  • Debug and analyze the root cause
  • apply patches to resolve problems

Adaptive Maintenance: Key Factors

• Purpose: Adapts system to evolve conditions
• Process:
  • Assess the impact of environment
  • Plan and implement
  • Testing

Perfective Maintenance: Key Factors

• Purpose: Enhances the system
• Process:
  • gather feedback
  • Impact and feasibility
  • Develop and test to deploy

Preventive Maintenance:Key Factors

• Purpose: Extend system Lifespan
• Process:
  • Monitor system
  • Backup Implementations
  • Audit Vulnerabilities

Documentation for System Maintenance

• Monitoring, identifying, troubleshooting etc are factors of System Maintenance

Challenges for System Maintenance

• Technical Debt (legacy systems make outdated code)
• Resource Constraints (Hinders Efforts)
• Changing Requirements
• Security risks

Monitoring Tools -

• Track system metrics.

Configuration Management Tools-

• Helps infrastructure.

Version Control Tools -

• Manage change.

Backup and Recovery-

• Ensuring data.

Security Tools -

• Protect.

Log Management Tools-

• Collect analysis.

Automation Tools-

• Streamline repetitive task.

Performance -

• identify and resolve performance