Lecture 02 – SDLC MODELS
SDLC MODELS
Software Development Lifecycle Models
Since the time software development started, various software models have been curated which implement SDLC. Each of these models solve problems that existed before these models were invented.
1. Waterfall Model
The Waterfall model is a classical model used in system development life cycle to create a system with a linear and sequential approach. It is termed as waterfall because the model develops systematically from one phase to another in a downward fashion, that means, until first stage is completed before moving to the next stage.
Waterfall model was among the first development models which is followed by SDLC.
Advantages of Waterfall Model
Disadvantages of Waterfall Model
2. Agile Model
Agile process model” refers to a software development approach based on iterative development. Agile methods break tasks into smaller iterations, or parts do not directly involve long term planning.
Advantages of Agile Model
Disadvantages of Agile Model
3. Lean Model
The Lean Development Methodology: Decrease Costs, Effort, and Waste. Lean software development is a set of principles that can be applied to software development to decrease programming effort, budgeting, and defect rates by one third.
Advantages of Lean Model
Disadvantages of Lean Model
Waterfall vs Agile vs Lean
Summarizing
The problem with WATERFALL MODEL was that the development lifecycle took lots of time to complete, therefore, by the time finished product was delivered, the product owner requirements were no longer the same.
This problem was fixed by Agile and Lean methodologies. These methodologies strictly focused on customers feedback and improving the software quality in a shorter development lifecycle.
