In the context of Agile and Scrum, there are two major software development models: iterative and incremental. While the terms ‘incremental’ and ‘iterative ’ are used interchangeably, there are certain differences that set them apart. Factors like product specifications and client requests should be considered by teams when choosing an appropriate development strategy. To help you understand which is the right approach for your Agile team, we’ll explore the basics of each approach and find out how they differ from each other.

What is Iterative Development?

The ever-changing needs of customers are compelling businesses to choose a development model that can cope with frequent customer feedback, adapt to changes at different stages or phases of product development, and help to develop products of the highest quality.

Here, the role of iterative development comes into the picture. The iterative development approach relies on repeated cycles known as iterations. IT professionals use this approach to develop, test, and then make necessary changes in the product as per the feedback received from customers. The new and enhanced features or functionalities are included in the latest software version which has to be released. This process is followed repetitively until the delivery of the final product. Learn more about how iterative development works in the CSM certification.

The iterative development process encourages feedback and improves the testing process to improve the product’s quality. The task of identifying defects or fixing any problems becomes easy when the product is tested and developed in small chunks. This ensures the product delivered is of high quality and aligns with the user expectations.

Understanding Incremental Development

In the case of incremental development, a product is developed in small parts or pieces known as increment. Every part undergoes cycles like testing, designing, execution, and functioning. The team develops functionalities step-by-step until the final product is built. The final product is visible to the client only after it has been developed completely. The team is familiar with the project’s final objectives.

The incremental development model focuses on the completion of the project in sections or increments that complement each other. The project team continues to add sections or increments until the project is complete.

This model is useful when a new technology is required during the project’s development,and the goals and needs are known. Besides, it’s suitable for industries that are more prone to risks. You can use incremental development if a specific product is in high demand as it guarantees quick delivery to the market.

Iterative Development vs Incremental Development

1. Errors

As each iteration is separate in iterative development, the task of identifying errors in the case of iterative development becomes easy. Teams can review the developed part to identify errors that should be eliminated in the upcoming iteration.

In the case of incremental development, each stage of the project is completed properly, however these parts cannot function solely. This signifies the project team won’t be able to detect errors until the project is completed or each part of the project is combined together to develop the final product.

2. Approach

In the context of the development process, the iterative model divides the project into fully functional and independent cycles or sprints. It allows team members to create better iterations by presenting a product prior to making adjustments.

Whereas, the final product can be developed in incomplete segments or small increments in the case of the incremental model. The functional product is presented only after the incomplete parts have been integrated together for the final delivery.

3. Costs

The iterative method involves many hidden costs as the project manager is unable to predict the number of iterations that will be required to complete the entire project. Each iteration of the project requires funding, which makes the iterative process extremely expensive. While it can seem easy to manage the costs in the beginning, it becomes necessary to expand the budget and resources over time.

Whereas the incremental method doesn’t require you to bear additional costs. The project can invest the allotted budget on a single iteration. Consequently, any additional expenses are more likely to be incurred only for minor modifications.

4. Quality

From the perspective of iterative development, the team develops low-quality and imperfect models of the end product. The team modifies the product over time to ensure the final product delivered is of excellent quality.

On the contrary, the team can use the incremental model to develop a refined version of the product upon completion of the first cycle. An end-to-end verification cycle can be carried out in the end.

5. Minimizing Risks

When it comes to minimising risks related to the project, the iterative method comes to the forefront. Whether a project team wants to make necessary modifications or conduct frequent product tests, the iterative process is beneficial. The objective is to make sure the final iteration is free from errors as the former issues have already been fixed.

In contrast, the team can only conduct product tests after the final process is completed. This increases the risks related to the project. This process is comparatively lengthier than the iterative process. Enrol in the CSPO certification to learn more.

6. Customer Engagement

The iterative method prioritises customer satisfaction and focuses more on client engagement. The client gets an opportunity to test the product after each iteration and exchange opinions.

Whereas the incremental method doesn’t allow users to engage during the iteration process. The client is allowed to use or test a developed product at the end of the development cycle.

Conclusion

The Agile world outlines the importance of both iterative and incremental development. To get started, it’s important to determine your project’s requirements – whether you want to deliver your project early or continuously refine it. As Agile encourages you to be more adaptive, feel free to combine the approaches together to find out the best solution for your product and team.