Iterative Development Model

Iterative Development Model

The practical software development project finds the classical waterfall method complicated. Practical software development projects use the Iterative waterfall model, which incorporates the necessary changes to make the classical waterfall model usable. The Iterative waterfall model is almost the same as the classical waterfall model, except it makes some changes to increase software development efficiency. The iterative waterfall model provides feedback paths from every phase to its preceding phases, which is the main difference from the classical waterfall model.

Real-life example:

The Iterative Waterfall Model could be building a new website for a small business. The process might look like this:

Requirements gathering:

This is the first stage, where the business owners and developers meet to discuss the goals and requirements of the website.


In this stage, the developers create a preliminary website design based on the requirements gathered in stage 1.
Implementation: In this stage, the developers build the website based on the design created in stage 2.


The development team builds the website and tests it to ensure it meets the requirements and functions correctly. The website is then deployed and made live to the public.

Review and improvement:

After the website has been live, the business owners and developers review its performance and make any necessary improvements.
This process is repeated until the website meets the needs and goals of the business. Each iteration builds upon the previous one, allowing for continuous improvement and iteration until the final product is complete.

Phase Containment of Errors:

Phase containment of errors is known as the principle of detecting errors as close to their points of commitment.


Throughout each stage of the process, there is collaboration between the business owners and developers. This ensures that the website meets the needs of the business and that any issues or concerns are addressed promptly.


The iterative waterfall model allows for flexibility in the development process. If changes or new requirements arise, they can be incorporated into the next iteration of the website.

Testing and feedback:

The testing stage of the process is essential for the identification of any issues or bugs that require addressing before deploying the website. Furthermore, gathering feedback from users or customers can help improve the website in subsequent iterations.


The iterative waterfall model scales and supports projects of various sizes and complexities. For instance, a larger business might necessitate more iterations or complex requirements, but the team can still follow the same process.


Once the website is live, ongoing maintenance is necessary to ensure it meets the business’s and its users’ needs. The iterative waterfall model can be used for maintenance and improvement cycles, allowing the website to evolve and stay up-to-date.

Advantages of the Iterative Waterfall Model :

Feedback Path:In the classical waterfall model, there are no feedback paths, so there is no mechanism for error correction. The iterative waterfall model allows for correcting the errors committed by having a feedback path from one phase to its preceding phase, which reflects in the later phases.

Simple : The iterative waterfall model is straightforward to understand and use. It is one of the most widely used software development models.

Cost-Effective: It is highly cost-effective to change the plan or requirements in the model. Moreover, it is best suited for agile organizations.

Well-organized :This model consumes less time on documents, and the team can spend more time developing and designing.

Risk Reduction: The iterative approach allows for early identification and mitigation of risks, reducing the likelihood of costly errors later in development.

Quality Assurance: The iterative approach promotes quality assurance by providing opportunities for testing and feedback throughout the development process. This results in a higher-quality end product.

Improved Customer Satisfaction: The iterative approach allows for customer involvement and feedback throughout the development process, resulting in a final product that better meets the needs and expectations of the customer.

Predictable Outcomes: The phased approach of the iterative waterfall model allows for more predictable outcomes and greater control over the development process, ensuring the project stays on track and within budget.

Faster Time to Market: The iterative approach allows for a shorter time to market as it makes small and incremental improvements over time, rather than waiting for a complete product to be developed.

Easy to Manage: The iterative waterfall model is easy to manage because it provides well-defined phases with a clear set of deliverables. This makes tracking progress, identifying issues, and managing resources easier.

Drawbacks of the Iterative Waterfall Model :

Challenging to incorporate change requests : The major drawback of the iterative waterfall model is that it is challenging to incorporate change requests. All the requirements must be clearly stated before starting the development phase. Customers may change requirements after some time, but the iterative waterfall model does not leave any scope to incorporate change requests made after the development phase starts.

Incremental delivery not supported: The development and testing team conducts the development and testing of the complete software before delivering it to the customer in the iterative waterfall model. There is no scope for any intermediate delivery. So, the customers have to wait a long time to get the software.

Overlapping of phases not supported : The iterative waterfall model assumes that one phase can start after completing the previous phase. Still, in real projects, phases may overlap to reduce the effort and time needed to complete the project.

Risk handling not supported: Projects may suffer from various types of risks. However, the Iterative waterfall model has no mechanism for risk handling.

Limited customer interactions: Customer interaction occurs at the start of the project, at the time of requirement gathering, and project completion at the time of software delivery. These fewer customer interactions may lead to problems as the finally developed software may differ from the customers’ requirements.


Examples of Iterative Development Model are:

Rapid Application Development(RAD)
Agile development