Top 7 Software Development Models You Should Know

The software development industry is one of the most fast-paced industries in the modern business world. In 2021, Grand View Research valued the global software development market size to be 429.59 billion and predicted its growth at a CAGR of 11.7% from 2022 to 2030. Thousands of new apps, websites, and platforms are released daily and more new technologies appear on the market to facilitate the work of software engineers. Such an erratic and ever-changing process requires certain boundaries to keep it under control and stick to the defined vision. Here are where software development models come into play.

These sets of rules, approaches, and methods allow development teams to organize work-related processes, clarify goals, make project estimates, and polish your solution to perfection. In this article, we will describe the most common SDLC models, their pros and cons, and the tips to choose the most suitable model for your team.

What are Software Development Models?

Before answering this question, let’s start with the definition of SDLC. Software development lifecycle, or SDLC, is a process of building and maintaining a software product. It usually includes several important stages that will lead you from an idea to a fully-functional solution:

• Planning

• Prototyping and design

• Development

• Quality assurance

• Launch

• Maintenance

Software development models can be defined as ways to organize and formalize these stages. Every company chooses a model that suits its working style and corporate culture best.  The choice also depends on factors like at what stage testing begins, what features are included in the first version, and when you can do the presentation.

It’s also possible for one company to adopt different models for different projects. Everything will depend on requirements, budget, and deadlines.

Top 7 Types of SDLC

Now, let’s get to the main part. There are a number of models in software development that an organization can choose from, and some are more popular than others. Here are the seven most common types of models that software engineers prefer in their practice.

Agile

Agile is not one but a group of models in software engineering that are based on iterative development and early feedback. Here, developers pay more attention to continuous testing that is adopted early in the project. It improves the quality of code but can result in complicated maintenance activities.

There are 12 main principles of Agile that are described in the Agile Manifesto:

1. Customer satisfaction through early and continuous delivery.

2. Welcoming changing requirements, even in the late development stages.

3. Frequent delivery.

4. Daily cooperation of business people and developers throughout the project.

5. Building projects around motivated individuals.

6. Face-to-face communication within the team.

7. Working software as the primary measure of progress.

8. Sustainable development.

9. Enhancing agility with continuous attention to technical excellence and good design.

10. Simplicity.

11. Self-organizing teams.

12. Regular reflection and analysis of teamwork and finding ways to make it better.

So, the main focus of Agile methodologies is high-quality code, early testing, and simple design. Also, Agile pays the utmost attention to the communication between a client and the software development team. When an iteration is finished, business owners review the progress and plan the next one together with the team.

The three most popular Agile frameworks are Scrum, Kanban, and Extreme Programming (XP).

• Scrum

This approach to Agile development is the most common one. Here, an iteration is called a sprint. It usually lasts from two to four weeks and consists of planning, design, coding, testing, and deployment. At the end of the sprint, the work is reviewed and evaluated, new priorities are set, and then the next sprint starts with planning again. No changes are allowed in a defined sprint.

• Kanban

Unlike Scrum, Kanban doesn’t work with definite iterations. And if there are any, they take no more than a couple of days. Instead, Kanban focuses on process visualization. With the help of a Kanban board, the team sorts out all the tasks they have on a project, indicates their priority, and assigns responsibilities.

The basic categories here are “Backlog,” “To do,” “In progress,” and “Done,” but you can add more. The tasks move from one category to another depending on the status. Communication with a client is ongoing and they can review the progress anytime.

• Extreme Programming (XP)

XP is the last Agile framework that follows the Agile Manifesto. The iterations here take about one or two weeks to complete. The model implies the utmost level of flexibility since changes can be made at the very beginning of a new iteration. However, such an approach can jeopardize the quality, so to work with XP, you need a strong infrastructure, highly-organized environment, and experienced talents.

Waterfall

Waterfall is another common approach to the software development process (and probably the oldest one). The stages in Waterfall are strictly established: The next phase can’t start if the previous one is not finished. And by “finished,” we mean that all processes and documentation should be fully completed. All these materials will become the input data for the next development stage. Waterfall comes with higher risks since there is no opportunity to see the product’s final version before the end of the very last stage.

Usually, it’s used for small-scale projects with clear requirements that are unlikely to change and a proven tech stack. This model will also be suitable for projects that have to follow a lot of regulations and require more control over processes.

Incremental (iterative) model

The Incremental model works with short iterations based on small sets of requirements. Each iteration results in a version of the product that you can then go through and see what next steps to implement. The subsequent iteration is planned according to new requirements.

Where Waterfall requires previous stages to be fully completed in order to move forward, an iterative model allows you to have several iterations in progress at the same time. This developmental model will help you test your product at each step and adjust your strategy if necessary.

V-shaped model

If you look at the picture above, you will understand where this model gets its name. Another name for this model is Validation and Verification. It’s a derivative of the Waterfall model, but in this version, testing is applied to each stage of development. Depending on what stage your project is in, you will need to perform a certain type of test. The list mentioned in the picture above is not the only correct set of testing options; you can rearrange and add more tests depending on your project’s needs.

The number of tests that this model contains can require a lot of time and budget, making the V-shaped model one of the most resource-consuming on this list. However, it will be efficient in projects that require the high levels of quality with no downtimes and critical bugs like healthcare software.

Spiral model

In this software engineering model, the risk assessment matters. So if you decide to go with it, you will need a team that has enough experience in working with risk management. The iterations here can last for several months and will include four main processes:

1. Determining objectives

2. Identifying risks

3. Development and testing

4. Planning the next iteration

When visualized, this model looks like a spiral covering the four quadrants. The result of each iteration is a prototype that you can test and see if any changes are needed before the release.

The spiral model will suit complicated and highly innovative projects since the model is customizable and flexible.

Rational Unified Process (RUP)

It’s a combination of linear (Waterfall) and iterative (Agile) approaches. The development is divided into four stages—inception, elaboration, construction, and transition. These make the linear part of the framework, and iterations happen within the limits of one stage. The core processes like UX/UI design and testing appear throughout all stages but with different levels of intensity.

DevOps model

DevOps stands for “development and operations.” This approach is meant to connect and coordinate the cooperative work of both Dev and Ops teams. The DevOps model is reliable, secure, and fast, providing you with high-quality results. The best practices of DevOps include:

• Continuous Integration and Continuous Delivery (CI/CD pipeline)

• Infrastructure-as-a-Code

• Microservices

• Automation

• Monitoring

• Collaborative culture

DevOps is a good choice for complex projects that requires a huge team involving people from multiple departments. However, if you decide to adopt this model, be ready for quite a challenging shift.

How to Choose the Most Suitable SDLC Models?

To make the right choice for your project, you will need to complete several steps:

1. Research the existing models and define which one corresponds to your company’s values and culture.

2. If there is anyone you need to get feedback from like top management or stakeholders, get that feedback.

3. Consider the following factors: the size and skillset of your team, your tech stack, project complexity, risks, the possibility of changes to the requirements, and flexibility.

4. Choose the model.

5. Adjust the model to your project requirements.

This strategy will help you learn what models in software development you can choose from and decide which one to stick to.

Software Engineering Models: Final Thoughts

We have mentioned the seven most popular software development models that are used by software engineers worldwide. Each of them has its own pros and cons and is suitable for different types of projects. The correct choice of an SDLC model will play a significant role in the product’s success.

When your team members know how they should work, it streamlines the development and sets clear expectations. Most developers across the globe use Agile (it’s our main choice too) and Waterfall, but your choice will depend on what exactly you want to create.

If you have an idea for a software project and want to partner with an Agile software development agency, feel free to drop us a line.