UNIVERSITY OF WEST ATTICA
SCHOOL OF ENGINEERING
DEPARTMENT OF COMPUTER ENGINEERING AND INFORMATICS
Software Quality and Reliability
Vasileios Evangelos Athanasiou
Student ID: 19390005
Georgios Theocharis
Student ID: 19390283
Omar Alhaz Omar
Student ID: 19390010
Supervisor: Christos Troussas, Assistant Professor
Co-Supervisor: Akrivi Krouska, Assistant Professor
Athens, February 2024
This document provides a theoretical overview of various Software Development Life Cycle (SDLC) models and methodologies, ranging from traditional sequential models to modern agile and collaborative approaches. It was prepared by students at the University of West Attica, Department of Informatics and Computer Engineering.
| Section | Folder/File | Description |
|---|---|---|
| 1 | docs/ |
Documentation on software life cycle models and methodologies |
| 1.1 | docs/Software-Life-Cycle-Models-and-Methodologies.pdf |
Documentation (English) |
| 1.2 | docs/Μοντέλα-και-Μεθοδολογίες-Κύκλου-Ζωής-Λογισμικού.pdf |
Documentation (Greek) |
| 2 | models/ |
Software development models illustrations |
| 2.1 | models/EN/ |
Model diagrams (English) |
| 2.1.1 | models/EN/agile.png |
Agile model diagram |
| 2.1.2 | models/EN/DevOps.png |
DevOps model diagram |
| 2.1.3 | models/EN/Extreme-programming.png |
Extreme Programming model diagram |
| 2.1.4 | models/EN/functional.png |
Functional model diagram |
| 2.1.5 | models/EN/Prototype.png |
Prototype model diagram |
| 2.1.6 | models/EN/scrum.png |
Scrum model diagram |
| 2.1.7 | models/EN/Spiral.png |
Spiral model diagram |
| 2.1.8 | models/EN/test-driven.png |
Test-Driven Development diagram |
| 2.1.9 | models/EN/unified_process.png |
Unified Process diagram |
| 2.1.10 | models/EN/V-Model.png |
V-Model diagram |
| 2.1.11 | models/EN/waterfall.png |
Waterfall model diagram |
| 2.2 | models/GR/ |
Model diagrams (Greek) |
| 2.2.1 | models/GR/agile.png |
Agile model diagram (Greek) |
| 2.2.2 | models/GR/DevOps.jpg |
DevOps model diagram (Greek) |
| 2.2.3 | models/GR/Extreme.png |
Extreme Programming diagram (Greek) |
| 2.2.4 | models/GR/Functional.png |
Functional model diagram (Greek) |
| 2.2.5 | models/GR/model V.jpg |
V-Model diagram (Greek) |
| 2.2.6 | models/GR/Prototype.png |
Prototype model diagram (Greek) |
| 2.2.7 | models/GR/Scrum.png |
Scrum model diagram (Greek) |
| 2.2.8 | models/GR/Spiral-Model.png |
Spiral model diagram (Greek) |
| 2.2.9 | models/GR/Test-driven.png |
Test-Driven Development diagram (Greek) |
| 2.2.10 | models/GR/Unified-process.jpg |
Unified Process diagram (Greek) |
| 2.3 | models/Intro3.jpg |
Introductory slide/image |
| 2.4 | models/questions.jpg |
Questions / summary slide |
| 3 | presentation/ |
Course presentation slides |
| 3.1 | presentation/#GR_Software-Methodologies_Present.pptx |
Presentation slides (Greek version) |
| 3.2 | presentation/Μοντέλα-και-Μεθοδολογίες-Κύκλου-Ζωής-Λογισμικού.pptx |
Presentation slides (Greek) |
| 4 | README.md |
Repository overview and usage instructions |
The Software Life Cycle (SDLC) is a structured framework guiding a project from inception to completion, defining stages such as requirements analysis, design, development, delivery, and maintenance.
- SDLC Model: Defines the stages of a software project.
- Methodology: A set of practices, techniques, and procedures used to organize and control development activities within those stages.
- Goal: To provide structured guidelines that improve efficiency and help achieve project objectives.
The Waterfall model is a linear and sequential development approach where each phase must be completed before moving to the next.
Typical Phases
- Requirements Analysis
- Architectural Design
- Detailed Design
- Coding and Testing
- System Testing
- Maintenance
Advantages
- Simple and easy to understand
- Well-structured and easy to manage
- Suitable for projects with stable and clearly defined requirements
Disadvantages
- Very rigid and inflexible
- Errors are often discovered late in development
- Returning to previous phases is difficult and costly
The V-Model extends the waterfall approach by associating each development phase with a corresponding testing phase.
Structure
Left Side (Development Phases)
- Requirements analysis
- System design
- Architectural design
- Detailed design
Right Side (Testing Phases)
- Unit testing
- Integration testing
- System testing
- Acceptance testing
Key Focus
- Verification and validation at each stage
- Frequently used in safety-critical or high-reliability systems
The document also introduces additional development models:
- Prototyping Model: Early software versions are built to clarify requirements and improve communication with stakeholders.
- Functional Augmentation Model: Features are added incrementally over time.
- Spiral Model: Combines iterative development with risk analysis and systematic planning.
Modern methodologies focus on flexibility, collaboration, and rapid delivery.
Key approaches include:
- Unified Process (UP): Iterative and incremental development framework.
- Agile Development: Emphasizes flexibility, customer collaboration, and continuous improvement.
- DevOps: Integrates development and operations to enable continuous integration and delivery.
- Scrum & Extreme Programming (XP): Agile frameworks emphasizing teamwork, feedback, and iterative progress.
- Test-Driven Development (TDD): Tests are written before implementation to guide development.
The final section of the report discusses how to select an appropriate development methodology based on:
- Project size and complexity
- Requirement stability
- Risk levels
- Team expertise
- Organizational environment
Selecting the correct methodology ensures better resource utilization, smoother development, and higher-quality results.
Understanding both classical and modern SDLC models helps organizations choose suitable development approaches. Proper selection and application of methodologies significantly improve project success and software quality.