Phương pháp Phát triển

Overview

Các phương pháp phát triển phần mềm (development methodologies) là các frameworks và practices giúp teams tổ chức và thực hiện công việc một cách hiệu quả. Mỗi method có ưu điểm và phù hợp với các tình huống khác nhau.

Main Categories

1. Traditional/Plan-Based Methods

Waterfall

Requirements → Design → Implementation → Verification → Maintenance
     ↓              ↓            ↓                ↓              ↓
   1990s       1990s-2000s   2000s           2000s         present

Sequential, document-driven
Each phase complete before next begins
Good for: Fixed requirements, stable projects

// Waterfall in practice - comprehensive upfront design
public class ProjectPlan
{
    // Detailed specification before coding
    public RequirementsSpec Requirements { get; set; }
    public ArchitectureSpec Architecture { get; set; }
    public TestPlan TestPlan { get; set; }
    public DeploymentPlan DeploymentPlan { get; set; }
}

V-Model

Requirements ←────────────── Acceptance Testing
    ↓                              ↓
System Design ←─────────────── Integration Testing
    ↓                              ↓
Detailed Design ←─────────────── Unit Testing
    ↓
Coding

Extension of Waterfall
Testing integrated into each phase
Good for: Safety-critical systems

2. Agile Methods

Scrum

Sprint Planning → Daily Scrum → Sprint Review → Sprint Retrospective
       ↓              ↓              ↓                ↓
     2-4 weeks     15 min         1-4 hours       1-3 hours

// Scrum artifacts
public class ProductBacklog
{
    public List<ProductBacklogItem> Items { get; set; }
    public void Prioritize() { } // Ranks by business value
}

public class Sprint
{
    public List<SprintBacklogItem> Backlog { get; set; }
    public SprintGoal Goal { get; set; }
    public Timebox Duration { get; set; } // Usually 2-4 weeks
}

public class DailyScrum
{
    // 3 questions:
    // 1. What did I do yesterday?
    // 2. What will I do today?
    // 3. Are there any blockers?
}

Kanban

To Do → In Progress → Review → Done
  ↓        ↓          ↓        ↓
 limits   limits     limits   limits

// Kanban board in code
public class KanbanBoard
{
    public Column ToDo { get; set; }
    public Column InProgress { get; set; } // WIP limit: 3
    public Column Review { get; set; }     // WIP limit: 2
    public Column Done { get; set; }
    
    public void MoveToInProgress(WorkItem item)
    {
        if (InProgress.Count >= InProgress.WipLimit)
            throw new Exception("WIP limit exceeded");
            
        InProgress.Add(item);
    }
}

Extreme Programming (XP)

Core Practices:
- Pair Programming
- Test-Driven Development
- Continuous Integration
- Refactoring
- Simple Design
- Customer Collaboration

// XP practices
public class XPPractice
{
    // Pair Programming: Two developers at one workstation
    // Continuous Integration: Every commit triggers build + tests
    // TDD: Red → Green → Refactor
}

3. Lean Methods

Principles

Eliminate waste
Amplify learning
Decide as late as possible
Deliver as fast as possible
Build quality in
See the whole

public class LeanPractice
{
    // Waste elimination
    // - Partially done work
    // - Extra features
    // - Waiting
    // - Handoffs
}

4. Modern Approaches

DevOps

Plan → Code → Build → Test → Deploy → Operate → Monitor
    ↑__________________________________________|
           Continuous feedback loop

# DevOps pipeline example
name: CI/CD Pipeline
on: [push]
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Run tests
        run: dotnet test
      - name: Build
        run: dotnet publish
      - name: Deploy
        run: deploy.sh

Continuous Delivery/Deployment

// CI/CD Pipeline stages
public class PipelineStage
{
    public const string BUILD = "Build";
    public const string TEST = "Test";
    public const string STAGING = "Deploy to Staging";
    public const string PRODUCTION = "Deploy to Production";
}

Comparison

Method	Flexibility	Documentation	Speed	Team Size
Waterfall	Low	High	Low	Any
Scrum	High	Low	High	5-9
Kanban	High	Medium	High	Any
XP	High	Medium	High	Small
DevOps	High	Low	Very High	Any

Choosing Right Method

Project Type	Recommended Method
Fixed requirements, safety-critical	Waterfall, V-Model
Complex, changing requirements	Scrum, Kanban
Small team, fast iteration	XP, Scrum
Operations-focused	DevOps
Startup, MVP	Agile, Lean

Hybrid Approaches

// Many teams use hybrid approaches
public class HybridMethod
{
    // Scrumban - Scrum + Kanban
    // Water-Scrum-Fall - Waterfall for planning, Scrum for execution
    // SAFe - Scaled Agile Framework for large projects
}

Key Practices

1. Iteration

public class Iteration
{
    // Short, time-boxed cycles
    // Each iteration produces working software
    // Feedback drives next iteration
}

2. Incremental Delivery

public class IncrementalDelivery
{
    // Deliver small pieces frequently
    // Each increment adds functionality
    // Early value to customers
}

3. Empirical Process

public class EmpiricalProcess
{
    // Transparency: Visible progress
    // Inspection: Frequent checkpoints
    // Adaptation: Change based on feedback
}

Learning