Software Development Life Cycle

The software development life cycle (SDLC) is a series of stages that helps organizations develop software in a well-structured way. It refers to a framework with clearly defined processes for creating high-quality software.

These days, many teams are moving towards an adaptive methodology, such as Agile, and moving away from more conventional ones such as the Waterfall methodology. 

The Waterfall methodology usually follows a strict series of steps or phases that details how the project from beginning to end, sticking to the original requirements.

Therefore, such a methodology is not adaptive to change and it usually takes a long time to deliver working software.

Agile software development grew out of frustration with the traditional Waterfall methodology to accommodate change and bring about faster software releases.

Agile practice helps you carry out continuous iterations of software development, with the end-goal to deliver high quality software to users as quickly as possible. 

For more on the differences between Agile and Waterfall methodologies, refer to this article here.

Software development life cycle stages

Despite the differences in methodologies, each development method uses the basic principles of SDLC. The only difference is that your team adapts each phase to suit the chosen methodology.

Before we discuss the steps of an Agile life cycle, we will provide a general overview of the stages in a traditional software development life cycle. The 7 stages of the a software development life cycle to develop software in a well-structured way are:

1. Planning
2. Requirements
3. Software design
4. Software development
5. Testing
6. Deployment 

The planning phase starts with defining the terms of the project by, for example, getting input from all stakeholders as well as its purpose and scope followed by determining the requirements of the application; in other words, what it’s supposed to do and the problem the software to be developed is addressing.

The design phase turns the software specification into a design including its architecture and user interface. Then, the software will be developed. Developers will start the coding process so there must be proper guidelines in place to implement the process.

Afterwards, the software built will be tested before making it available for end-users to make sure it’s working as it should. Some of the testing can be automated. At this stage, developers must ensure that the software is free from bugs. 

Finally, the software can be released or deployed to the production environment and made available to users. 

There may be a final ‘maintenance’ phase, where bugs that weren’t discovered during testing will need to be resolved. The software may also need to be updated and additional features added in the future.

Phases of the Agile life cycle

In an Agile SDLC methodology, work is done in regularly iterated cycles known as sprints, often lasting for two to four weeks. It is largely driven by customer feedback and so helps developers build software based on this feedback.

1. Concept- this is where the product manager will determine the scope of the project. The key requirements are discussed and outlined.
2. Inception- this is the stage where the software development team is put together and the requirements are fleshed out.
3. Iteration- this is the longest phase as most of the work into the software is carried out here. Developers start working on the first iteration of the software to deliver the bare functionality of a product; this product is not fully functional and not the final version as it will require numerous revisions to end up with the final required functionality. However, additional features can be added in later iterations.
4. Release- QA tests are carried out to ensure the software is fully functional as well as user training which will require documentation then the product’s final iteration can be released into production. End-users can use this product and feedback will be gathered accordingly.
5. Maintenance- the software at this point is fully deployed and made available to customers. During this phase, developers will provide ongoing support to keep things running smoothly and remove any bugs. They would also offer additional training to users so that they know how to use the product. Further iterations may be introduced if necessary to improve the existing product and introduce new features.
6. Retirement- the final phase is where the product may be replaced with new software or the system itself is no longer in use by the organization so they will notify users and, where relevant, help them migrate to the new system. Developers will then carry out end-of-life activities.

The Agile model is more flexible and employs iterative methods, which is creating software by modifications and changing requirements to satisfy customer needs and increase productivity. Unlike a traditional model, which does not allow for major changes in later stages, it allows for rapid changes after the initial stages of the project.

Additionally, since there are frequent builds within an Agile model, it offers the ability to detect any deviations from customer requirements, which can be resolved early on.

Conclusion

In the end, the methodology and framework you decide to adopt will largely depend on your project needs.

An Agile methodology has clear benefits as it aims to produce rapid solutions, which can enhance productivity as well as customer satisfaction by providing them with high quality software suited to their needs.

Before starting your software development process, it is important to understand which methodology best fits your requirements. The size of the team, complexity of the software and engineering capability are some of the factors that you will need to consider to make an informed decision.