Exam Board:
OCR A-Level
2.3 - Software Development
Specification:
Computer Science H446
Watch on YouTube:
Waterfall Lifecycle
Extreme Programming
Spiral Model
Rapid Application Development
Software development models are step-by-step methods for creating and maintaining software. They are used to keep projects organised, reduce mistakes and make sure the finished program meets the user’s needs. Different models suit different types of projects.
Waterfall Lifecycle
The waterfall model is a linear and structured approach where each phase is completed one at a time in order.
It needs all requirements to be clearly defined at the start, with little to no changes allowed once a phase is finished.
This model is best suited for projects with fixed requirements and minimal risk of change.
Extreme Programming
Extreme Programming (XP) is a type of agile methodology that uses an iterative and flexible approach, progressing in small, usable chunks called iterations (or sprints).
It relies on frequent collaboration with stakeholders and user feedback to adapt to changing requirements.
​
This model is ideal for dynamic projects where quick delivery and frequent updates are important.
Spiral Model
The spiral model combines iterative development and risk management, progressing through repeated cycles of planning, risk assessment, engineering (development and testing) and evaluation.
​
Each loop focuses on identifying and addressing risks early in the project.
​
It is ideal for complex and high-risk projects where requirements may change over time.
Rapid Application Development
The rapid application development (RAD) model focuses on quickly building software through iterative development and frequent user feedback.
It uses reusable components, time-boxing and constant feedback to speed up the delivery of an effective final product.
RAD is best suited for projects that need to be completed quickly and where requirements can evolve during development.
Questo's Key Terms
Software Development: waterfall lifecycle, agile methodology, extreme programming (XP), spiral model, rapid application development (RAD)
Did You Know?
Agile development is named after the 'Agile Manifesto' - a set of principles for software development agreed by a group of developers at a ski resort in Utah, USA in 2001.
