12 - 1.2.3 a & b Programming Methodologies

• Computing
• Further Education (Key Stage 5)

12 - 1.2.3 a & b 

a) Programming Methodologies

b) Merits, drawbacks and uses of programming methodologies

Programming methodologies

Waterfall lifecycle

Agile methodologies

Extreme programming

Spiral model

Rapid application development

Waterfall

The Waterfall methodology is a traditional approach to software development where each phase must be completed before moving on to the next. 

(linear and sequential)

Waterfall - Stages

Analysis:

Gather and document all software requirements.

Establish clear objectives and specifications.

Feasibility Study

Design:

Design the architecture and components of the software.

Create detailed design documents.

Implementation (Coding):

Translate design into executable code.

Develop and integrate all system components.

Evaluation (Testing):

Verify that the software meets all requirements.

Identify and fix defects.

Maintenance:

Perform ongoing support and maintenance.

Address any issues that arise post-deployment.

Waterfall Pros and Cons

Waterfall - Pros and cons

Advantages:

Structured Approach: Clear, defined stages with specific deliverables.

Easy to Manage: Simple to track progress and milestones.

Documentation: Comprehensive documentation at each phase aids future maintenance.

Disadvantages:

Inflexibility: Difficult to accommodate changes once a phase is completed.

Late Testing: Issues may only be discovered in the testing phase, potentially causing significant delays.

Customer Feedback: Limited opportunities for customer feedback during development.

Best for Projects: Where requirements are well understood and unlikely to change.

Examples: Government projects, large-scale system implementations with fixed requirements.

Agile Methodologies

Agile methodologies focus on iterative development, where requirements and solutions evolve through collaboration between cross-functional teams.

Agile Key Principles:

Customer Collaboration:

Continuous customer involvement and feedback.

Regular updates and demonstrations of progress.

Responding to Change:

Flexibility to adapt to changing requirements.

Iterative cycles allow for regular reassessment and adjustment.

Working Software:

Frequent delivery of small, functional increments.

Emphasis on delivering a usable product at the end of each iteration.

Team Collaboration:

Close, daily cooperation among team members.

Self-organizing teams with shared responsibility.

Agile Methodologies Pros and Cons

Agile - Pros and cons

Advantages:

Flexibility: Easily accommodates changing requirements.

Customer Satisfaction: Regular feedback ensures the product meets user needs.

Risk Reduction: Early and frequent delivery of working software reduces risks.

Disadvantages:

Scope Creep: Continuous changes can lead to scope expansion.

Requires Discipline: Teams must be well-coordinated and self-motivated.

Documentation: May lack comprehensive documentation compared to traditional methods.

Best for Projects: Where requirements are expected to evolve or are not well understood initially.

Examples: Software startups, dynamic environments, projects requiring rapid iteration and feedback.

Extreme Programming

Focus on Technical Excellence: Extreme Programming (XP) is an Agile software development framework that emphasizes high-quality code and adaptive practices.

Extreme Programming

Pair Programming:

Two developers work together at one workstation.

One writes code, the other reviews and offers suggestions.

Test-Driven Development (TDD):

Write tests before writing the code they test.

Ensure all code is covered by tests to maintain quality.

Continuous Integration:

Integrate code changes frequently into a shared repository.

Automatically test and build the software to detect issues early.

Refactoring:

Continuously improve the codebase without changing its behavior.

Enhance code readability, maintainability, and performance.

On-Site Customer:

Have a customer representative available to provide immediate feedback.

Ensure the development team understands the customer's needs.

Extreme Programming Pros and Cons

Extreme Programming - Pros and cons

Advantages:

High Code Quality: Practices like TDD and refactoring ensure robust, maintainable code.

Rapid Feedback: Immediate feedback from tests and customers helps to quickly correct issues.

Strong Collaboration: Pair programming and close communication enhance teamwork and knowledge sharing.

Disadvantages:

Resource Intensive: Requires significant time and effort from all team members.

Demanding Discipline: High levels of discipline and commitment needed to maintain practices.

Initial Slowdown: Initial learning curve may slow down development at the start.

Best for Projects: That require high-quality, maintainable code and where requirements may evolve.

Examples: Critical software systems, projects where changes are frequent, and high-collaboration environments.

Spiral

 The Spiral Model combines iterative development with systematic aspects of the Waterfall model, emphasizing risk management.

Spiral

Analysis:

Determine objectives, alternatives, and constraints.

Establish project scope and gather requirements.

Risk Assessment:

Identify and assess risks associated with the project.

Develop strategies to mitigate identified risks.

Implementation:

Design, code, and test a prototype or a part of the system.

Implement solutions to resolve risks and gather user feedback.

Evaluation:

Review and evaluate the prototype with stakeholders.

Plan the next iteration based on feedback and performance.

Spiral Pros and Cons

Spiral

Advantages:

Risk Management: Focuses on identifying and mitigating risks early.

Flexibility: Iterative approach allows for changes and refinements at each stage.

Customer Feedback: Regularly incorporates user feedback through prototypes.

Disadvantages:

Complexity: Managing and tracking spirals can be complex.

Cost: Can be more expensive due to repeated prototyping and extensive risk analysis.

Expertise Required: Requires skilled project managers to assess and manage risks effectively.

Use Cases:

Best for Projects: With high risks and significant user interface components.

Examples: Large-scale systems, complex projects with evolving requirements, projects where risk management is crucial.

Rapid Application Development

RAD emphasizes quick development and iteration of prototypes over rigid planning and testing.

Rapid Application Development

Prototyping:

Develop functional prototypes to gather user feedback quickly.

Iterative refinement based on feedback.

User Involvement:

Continuous user participation throughout the development process.

Users provide feedback and validation at each iteration.

Iterative Development:

Break projects into smaller, manageable tasks.

Develop, review, and refine in short cycles.

Component-Based Construction:

Reuse pre-built components to speed up development.

Focus on assembling existing parts rather than coding from scratch.

Phases: 

Requirements Planning:

Conduct workshops to gather broad requirements.

Establish project scope and objectives.

User Design:

Collaborate with users to create prototypes.

Design and refine user interfaces through feedback.

Rapid Construction:

Develop prototypes into working models.

Use iterative cycles to build and refine functionality.

Cutover:

Finalize the system by testing and implementing.

Transition from development to production.

Rapid Application Development pros and cons

Rapid Application Development

Advantages:

Speed: Accelerates development process with iterative prototyping.

Flexibility: Easily accommodates changes and new requirements.

User Satisfaction: High user involvement ensures the final product meets user needs.

Disadvantages:

Scope Management: Risk of scope creep due to continuous changes.

Quality: May compromise on thorough testing and documentation.

Dependency on Skilled Developers: Requires experienced developers to manage rapid iterations.

Use Cases:

Best for Projects: Where time-to-market is critical and requirements are expected to evolve.

Examples: Web and mobile applications, user interface-focused systems, projects with a high need for user feedback.

Analysis

Design

Implementation

Evaluation

Maintenance

Scenario 1:  Government Project with Strict Requirements

Which software development methodology would be most suitable for a government project with strict, unchanging requirements and a need for thorough documentation? Why?

Scenario 1: Government Project with Strict Requirements
Which software development methodology would be most suitable for a government project with strict, unchanging requirements and a need for thorough documentation? Why?

Scenario 2: A mid-sized sales company is struggling with its current Customer Relationship Management (CRM) system. The system is outdated, not user-friendly, and lacks integration with other tools the sales team uses daily. The company wants a custom CRM solution that can be adapted quickly to their changing needs and can integrate seamlessly with their email, calendar, and communication platforms.