Iterative Model (Software Engineering) | SDLC - Iterative Model

The iterative model is a software development life cycle (SDLC) approach in which the initial development is started based on the initial requirements that are clearly defined and subsequent features are added to the base software product through iterations until the final system is completed. At each iteration, design modifications are made and new functional capabilities are added. The basic idea behind this method is to develop a system through repeated cycles (iterative) and in smaller portions at a time (incremental).

Unlike the more traditional waterfall model, which focuses on a step-by-step process of development stages, the iterative model is best thought of as a cyclical process.

An iterative life cycle model does not attempt to start with a full specification of requirements. Instead, development begins by specifying and implementing just part of the software, which is then reviewed to identify further requirements. This process is then repeated, producing a new version of the software at the end of each iteration of the model. It is specifically designed to start with the bare minimum requirements and only construct a portion of the program iteratively.

In this model, we can start with some of the software specifications and develop the first version of the software. After the first version if there is a need to change the software, then a new version of the software is created with a new iteration. It will repeat until deployment of the software. 

The various phases of Iterative Model are as follows:

Requirement gathering & analysis: In this phase, requirements are gathered from customers and check by an analyst whether requirements will fulfill or not.

Design: In the design phase, team design the software by the different diagrams like Data Flow diagram, activity diagram, class diagram, state transition diagram, etc.

Coding: The actual construction of the system begins at this point in the project. All planning, specification, and design docs up to this point are coded and implemented into this initial iteration of the project.

Testing: After completing the coding phase, software testing starts using different test methods to identify and locate any potential bugs or issues that have have cropped up. There are many test methods, but the most common are white box, black box, and grey box test methods.

Review: The review phase is where the software is estimated and checked as per the current requirement. Then, further requirements are reviewed discussed and reviewed to propose for an update in the next iteration.

Deployment: After completing all the phases, software is deployed to its work environment.

Maintenance: In the maintenance phase, after deployment of the software in the working environment there may be some bugs, some errors or new updates are required. Maintenance involves debugging and new addition options.