Iterative Model

Iterative model is considered as an incremental model, where the software or a project is broken down into many large iterations and where every single iteration is a complete development loop which results in a release of executable product of software. Rapid application model is an example of iterative model. The development of the iterative model in SDLC is a manner of breaking down the software huge application into shorter segments.

In iterative model, the development begins by specifying and also by implementing the part of software which can be then again viewed in order to identify further requirements. This process is will be repeated by producing a new version of the software for each cycle of the model.

Advantages:

In this model, we will create a high level design of the application before we actually begin to build the product and define the design solution for the entire product.
Here we build and improve the product step by step by which we can track the defects at early stages.
In this model, we can get the reliable user feedback.
In this model less time is spent on documenting and also more time is given for implementation of software.

Disadvantages:

In each step of iteration, it is rigid with no overlaps.
It has expensive system of architecture or design issues may arise because all requirements are not gathered up front for the entire cycle.

We have to use the iterative model when requirements of the system will be completely defined and understood. Whenever the project is big. Many requirements must be defined.

AGILE:

Agile has the capability to create and respond to change. It is a way of proceeding with, and ultimately succeeding in an uncertain and turbulent environment. “Agile”, the word means the adaptiveness and response to change which is so important to their approach.

Agile software development is team with a group of frameworks and practices based on values and principles as expressed in the manifesto for agile software development. When anyone approaches software development in a particular manner, its generally good to live by these values and also by principles and use them to help figure out the right things to do given your particular context.

Agile methodologies:

Agile methodologies are conventions which a team chooses to follow in a style that follows agile values and principles. There are some methodologies like scrum and XP which are agile methodologies, these were considered as framework by Alistair. They were born from a single team’s methodology and they were considered as frameworks when they will be generalised to be used by other teams.

Why to choose agile?

When we ask any developer about their shifting from waterfall model to agile we will get to hear an earful of many benefits about the agile. Agile is a process at the team level. It is effective and achieve desired market and business goals. It is always essential to get the team’s daily work with coordination with an organisations strategic objectives. Agile helps organisations in many industries to improve product quality, time to market and employee satisfaction.

AGILE SCRUM:

Scrum is a framework which helps the software team work together. It encourages the team to learn by its experiences, self-organize while working on a problem and always highlights their wins and losses to continuously improve. Scrum is used by software development teams, its principles and lessons can be applied to all kinds of teamwork. This is reason scrum is very popular. Scrum explains a set of meetings, tools and roles that work in concert to help teams structure and manage their work.

A scrum procedure is differentiated from agile by a particular concepts and practices which are divided into three categories of roles, Artifacts and Time boxes. Scrum is often used to manage difficult software and product development. Scrum procedure benefits the organisation by helping as mentioned below: