What Are The Software Development Life Cycle (SDLC) Stages and Models

Software development life cycle stages and models

Software Development Life Cycle (SDLC) is a process that helps development teams define the steps involved in each phase of software development.  Instead of trying to do everything at once, teams visualize the entire project and analyze the steps they need to take to produce high-quality software that meets customers’ expectations. These steps are divided into tasks that are assigned, completed, and measured. 

Briefly explained, the SDLC traces a plan that describes how a specific software will be built and maintained.  It has 7 basic steps: Planning, requirements, design and prototype, software development, testing, deployment, and maintenance. In some cases, depending on different variables (project, team, manager, etc.), certain steps can be omitted, split, or combined.

During this article, we will review each of the stages and models of the software development life cycle. 

What is Software Development Life Cycle?

In software engineering, the software development life cycle – mostly known as SDLC – consists of planning, creating, testing, and launching an information system. This process allows tech teams to measure and improve the process’s development as it analyzes each one of these steps in detail. Consequently, it helps companies maximize efficiency at each stage.  

The primary purpose of SDLC is to deliver a high-quality product that meets and exceeds the client’s or company’s expectations. Additionally, it helps companies and teams reduce costs and release software faster by identifying inefficiencies and higher costs and fixing them to run smoothly. 

These are SDLC main benefits and its advantages:

  • It offers a foundation for project planning, scheduling, and estimating.
  • Improves relations with clients.
  • Helps tech teams to decrease project risks.
  • Helps project management to plan with anticipation.
  • Increases visibility throughout the entire development process.
  • Reduces costs.
  • It helps keep track and control of the project.
  • Enhances development speed.

What are the Stages of SDLC?

There are 7 phases of the software development life cycle, which divide the development process into assigned tasks, completed, measured, and improved by IT teams. The steps can vary depending on which SDLC model is implemented. 

These are the 7 stages of SDLC: 

The 7 Phases of Software Development Life Cycle

1. Planning

During this first phase, the project leaders define the project’s purpose and the desired result. In case the software application is for a customer, it happens the same.  The project manager reunites with the customer to discuss the product, its purpose, and the results they want to achieve. The team gathers as much information about the product from the customer.

In the planning phase, leaders are evaluating the terms of the project. Including how much the project will cost and who will be part of that project. They also target specific goals during a time frame, and overall, they create the basic structure for the project.

2. Requirements

This second phase is part of the planning.  The SDLC starts with a requirement analysis phase in which the person in charge of the project establishes the software requirements. They analyze the aspects that are necessary to achieve the final goal. Defining and establishing requirements determines what the application will do and the resources needed to build the project. For example, if a team wants to develop software to control a robot that cleans, then the physical robot would be a requirement in the process.

During this second phase besides establishing the requirements for the final product, each member of the team has to understand their roles and tasks.

3. Design and Prototype

Once phases 1 and 2 are understood and established, developers can start designing the software. The design phase is what defines the way a software application will work. During this phase, teams establish the programming languages, screen layouts, and relevant documentation they will be using.  Some of the fundamental aspects developers cover during this phase are:

  • Architecture: Teams define if they want a specific type of template or if they want to implement any type of industry practice.
  • User Interface: Teams define the way users will be interacting with the platform. Developers must build user-friendly platforms to increase engagement. That’s why planning these steps is crucial for how well the platform will perform.
  • Security: Developers must define how they will keep the application secure. This means they need to see how to protect passwords, and overall, create strategies to keep all of the app data safe.
  • Programming: Define what type of programming languages they will be using as well as what methods they will implement if they face problems or need help. 

Prototyping is also part of this phase. A prototype is the basic idea of how the application looks and works. Prototypes are a way for customers to get a sneak peek of how their application will look; they might even discover their original idea is not good enough and change it during this phase.

4. Software Development

During this phase, developers start the development of the software. If they work in a small project, one developer takes over the coding tasks, while on large projects, it might be divided and operated by different developers. Before starting to code, teams need to have clear predefined coding guidelines to reassure the quality of the code.  In this phase, developers start building the entire system and giving shape to the project.

Depending on each team’s model, the phase may be conducted in sprints (Agile) or a single block (Waterfall). The majority of times, teams spend most of their time during this phase to ensure that the application will work efficiently.

5. Testing

All the SDLC phases are important, but testing is where developers get nervous and hug each other, crossing their fingers that their hard work pays off.  Different types of testing occur during this phase, such as code quality, unit testing, integration testing, performance testing, and security testing.

During this phase, developers fix bugs or small errors that might appear during the tests. The application can’t be released with errors on it, that’s why testing has to be made with caution and as many times as needed. The objective is for users to be highly satisfied with the new app, use it regularly, and invite other people to use it. There is also the option to automate some tests to ensure that they are never skipped.

6. Deployment

The deployment process starts once the testing phase is over, and there are no bugs or errors in the system. During this phase, the tech support team joins, providing user feedback. The team makes sure that the software is up-to-date, and it’s secure enough for users.

In big teams, this phase is usually invisible because it’s automated. But for startups or small organizations, this process needs to be done manually. It depends on the experience of the team members and the type of application they are building (some apps are more complex than others).

7. Maintenance

At this point in the SDLC cycle, the application is successfully finished and being used. Yet this last phase is still important because it’s where bugs or small errors appear. Users might face some malfunctions in the app, which is why developers need to be ready to fix them quickly. During this phase, the team can develop new upgrades with features to make the application even better. 

KPI software development

SDLC Models and Methodologies 

As mentioned previously, Software Development Life Cycle is a continuous process from start to finish of a software application. And even though there are specific steps, teams adopt different methodologies that have diverse approaches to build their applications. There is not one single model; there are many. The most popular SDLC models are Waterfall, V-Shaped, Iterative, Spiral, Big Bang, Prototype, and Agile.

1. Waterfall Model

The waterfall model was the first one of the SDLC process. This model consists of dividing all the phases of the project, each phase with its own tasks and objectives. This model includes gradual execution of every stage completely, meaning that the output of one phase is the input of the next phase. If one phase is not completed, it’s not possible to move forward to the next one. Another characteristic of the Waterfall model is that it’s strictly documented and has predefined features expected to be developed in every phase.

The waterfall model looks like this:

Waterfall model (SDLC)

2. V-Shaped Model

This SDLC model is also known as the validation and verification model because it focuses on testing every stage before passing to the next one. This means every stage has a control process to make sure that the development works perfectly, and it’s possible to start with the next phase of the process.

The V-shaped model looks like this: 

V-shaped model (sdlc)

3. Iterative Model

The iterative model is all about repetition. Instead of starting fully knowing all the requirements, developers implement a set of software requirements, test them, and improve them. So, a new version of the software is produced in every iteration. This happens again and again until the project is finished. 

The iterative model looks like this: 

Iterative model (sdlc)

4. Spiral Model

The Spiral model combines architecture and prototyping by stages.  This model allows products to be released and refined through each phase of the spiral. Also, it’s possible to build prototypes at each phase, making it possible to detect and manage risks. This is why this model is the perfect solution for big and expensive projects – before spending more money and time, developers and the team build an application that can detect future problems. 

The spiral model looks like this:

Spiral Model (sdlc)

5. Big Bang Model

One of the simplest models of SDLC is the Big Band Model. It basically starts from nothing as it doesn’t have a defined and strict process. It doesn’t require much planning and scheduling. However, it requires a lot of funds, and coding usually takes more time. 

The Big Bang Model is mostly used in small projects or for academic purposes. It’s ideal for teams that don’t have specific requirements or an established releasing date.

The Big Bang model looks like this:

Big Band Model

6. Prototype Model

In this model, the prototype is built before the software. Prototype models have limited functional capabilities and inefficient performance when compared to the actual software. However, they are helpful when teams want to get valuable feedback from the customer. 

The process in this model starts by interviewing the customers and developing an incomplete model with the initial prototype that supports the basic functionality desired by the customer. The customer evaluates, provides feedback, and the team continues working on the prototype. The process continues until the user approves the prototype.

The Prototype model looks like this:

Prototype SDLC Model

7. Agile Model

The Agile SDLC methodology strongly emphasizes developer-client communication. After every development iteration, the customer can see the results and let the team know if they are satisfied.  Therefore, work is done in regularly iterated cycles that are identified as sprints—projects under the Agile model last usually from two to four weeks. This is one of the most popular models for remote teams

The Agile model looks like this:

Agile Model (sdlc)

Scaling Your IT Team?

No matter which SDLC model you choose and how perfectly you design your project, without the right software development team, success won’t be possible. It’s like having a room full of Fender guitars and hiring doctors instead of musicians to play (not that doctors can’t play, but you get the point).

We know finding talented developers might be one of the most frustrating things.  But with the right tools and headhunting skills, it’s more than possible. How are we so sure about this? 

DistantJob’s IT recruiters have been doing it for the last decade. They are specifically trained in global human resources recruitment. You just tell us what type of remote developer you are seeking for your team, and in less than two weeks, our remote recruiters (we practice what we preach) will find the right candidate that will share your company’s values and will work with you directly.

Share this post

Share on facebook
Share on google
Share on twitter
Share on linkedin
Share on pinterest
Share on print
Share on email

or... Subscribe to our newsletter and get exclusive content and bloopers

Gabriela Molina

Gabriela Molina

Gabriela Molina is the writer and executive editor of the DistantJob blog. As a former freelance journalist, she has covered a wide range of topics throughout her career. She was featured in Datasciencentral, Simpleprogrammer, to name a few. She is currently specializing in the areas of technology, leadership, and remote work.