Agile SDLC: Skyrocketing Your Project with Agile Principles

• Overview of Traditional and Agile SDLC Models
• Agile SDLC Model: Main Underlying Processes
• Agile SDLC: Is it Suitable for Your Next Project?

Timely development and delivery of software are among the main tasks software development companies are facing today. Agile SDLC offers a flexible approach to software development in a fast-paced environment with ever-changing customer needs.

The main benefit of Agile software development life cycle implementation is plain to see. The Agile approach embraces the constant changes that prevail in software development processes. Teams can deliver working software quickly and release updates more frequently. It seems that there is no reason not to adopt Agile SDLC.

In this article, we discuss the Agile SDLC model, how it correlates to traditional SDLC models, and how to make use of the best Agile practices.

Overview of Traditional and Agile SDLC Models

The modern technical world is dominated by rapid changes that developers are required to keep up with while still delivering top-notch software on time. Companies use various approaches to streamline the development process. This is where different software development life cycle models are applied. Below, you will find an overview of both traditional and Agile SDLC models and the benefits they offer.

Software Development Life Cycle: Uncovering the Basics

Everyone knows that proper planning gets you halfway to success. The IT sphere is no exception, as planning forms the basis for software development and directly influences the quality of the final project. This is why the software development life cycle is so important.

The software development life cycle, also called the application development life cycle, defines how the development process is built within a project or a whole company. The SDLC is also called a framework for planning, development, testing, control, and delivery of provided software development services. When SDLC is applied, it is easy to find out what stage the team is on, what resources are required, and what phase is next.

The Main Phases of SDLC Models

Any software development life cycle is comprised of several phases. Traditionally, the six product development life cycle stages are as follows:

• The first phase is dedicated to requirement gathering and analysis. All vital information is gathered and analyzed. This step is designed to resolve all ambiguities regarding future software.
• Design is the second phase of the software development life cycle. This is where the entire architecture of the future project is created.
• Coding, which is also called implementation, is the third phase in SDLC. All the components of the designed software are implemented, and the source code is created.
• Testing involves the checking of any faulty parts of the code and their fixes. Everything is thoroughly tested and, if needed, re-tested until all problems are solved.
• After the software has been tested and all necessary iterations are made, it enters the deployment phase. The project is then released to end users.
• Maintenance accompanies software along its whole life cycle. If users find any issues, depending on how severe they are, the problem can be hot-fixed or fixed with the next planned release.

Depending on how the team prefers to make its way through these phases, a few SDLC methodologies can be employed, including but not limited to Waterfall, Iterative, Spiral, and Agile SDLC models.

What is Agile Software Development Life Cycle?

Agile SDLC

Up to date, Agile SDLC is one of the most popular software development models. The year 2001 is considered to be the beginning of Agile methodologies. Seventeen software developers published the Agile Manifesto that described the underlying principles of Agile best practices.

Provided flexibility is the first and foremost benefit of the Agile software development life cycle. The model promotes the development of software in small, quick steps. Agile practices are based on continuous iterations of software that allow companies to release updates to users more frequently. Each new release serves as a base for the next one.

A development team or company must complete a phase before moving to the next one. This is the main differentiating factor from traditional software development life cycle models.

In traditional software development, a company has to make a detailed overview of all the needs that might come up in the future and design software so that it meets all the predicted requirements. This makes the traditional development process time-consuming.

In Agile software development, on the other hand, a company determines the scope of required changes and goes through the cycle of analysis, design, development, and testing. This allows the team to release small changes into production instead of releasing a single major update. One such cycle, usually called a sprint, may range from a couple of weeks to 30 days, and varies from company to company.

Agile software development life cycle is designed to contribute to continuous software deliverables, continuous project improvements, instant updates, and rapid development. The Agile SDLC methodology is based on two approaches – iterative and incremental.

Instead of creating a detailed overview of predicted needs and sticking to it throughout the whole development process, a company applies an incremental approach. With incremental development, software is created piece by piece. New functionality is added at each step and new features are built on top of existing ones. This approach helps to deliver the minimum viable product (MVP) really fast.

An iterative approach means that you create new software through refinements. You create an MVP and, later, refine the features and various tools. This approach helps the development team simultaneously work on various parts of a product and make changes easily.

There are many Agile SDLC approaches including, but not limited to, Scrum, Kanban, Scrumban, Extreme Programming (XP), Feature Driven Development, and Lean Software Development. However, they all are united by one goal – quick adaptation to changes and delivery of working software as fast as possible.

Traditional SDLC vs Agile SDLC: Comparing the Models

All software development methodologies can be divided into either adaptive or predictive. Agile SDLC is a part of the adaptive subcategory, while Waterfall, V-shaped, Iterative and Spiral models all belong to the predictive approach. All of them are designed to meet a number of development requirements and expectations that vary from company to company.

Traditional SDLC Models

As the Agile software development life cycle is mostly compared to the Waterfall software development life cycle, we’ve included a detailed Agile vs. Waterfall comparison in the next chapter of this article. For now, we’ll focus on other predictive software development models:

• V-shaped SDLC Model is based on the Waterfall model. The development process is like flowing water, where the development team moves step by step through different SDLC stages. Every stage ends with testing and a team moves on to the next only after the previous stage is complete. This model is also called Validation-Verification, as the test helps to check whether all requirements have been fulfilled and if the team can move on to another software development phase.

Just remember that by utilizing the V-shaped SDLC model you cannot easily move back a step to fix or add something. If your software product is new, has many features to be implemented, or you are not sure about the final functionality, this model won’t work for you.

• The Iterative approach can be applied in projects without the full list of requirements. A team only needs the requirements for the functional part. These requirements can be expanded upon later on in the development process. The approach goes through all SDLC steps, from analysis, to design, to coding, to testing, and back to analysis. The process is repetitive and allows for the creation of a new product version for every cycle.

Each iteration lasts from two to six weeks and the result in mind is the release of a new component, which is then added to the existing components and features. The team gradually moves the project to the final version of the planned software. The main disadvantage of this model is the need for repetitive iterations. The process should be used wisely, otherwise it may quickly drain the resources for unnecessary changes. The Iterative approach is not the best choice for startups with limited financial means.

• Spiral SDLC Model places a great emphasis on risk analysis. The whole development process is divided into a lot of small phases for teams to follow. This poses the danger of losing time and money if the product is new and the final product does not need to be excessively documented. This model may also be too expensive for small and low-risk projects.

However, before jumping to a conclusion, we also need to consider another essential model – Waterfall.

Waterfall vs Agile SDLC: Why Companies Choose the Agile Approach

Waterfall Methodology Phases

Waterfall model is considered to be the oldest among SDLC models and underlies several other software development approaches, like the V-shaped and Spiral models. It was developed in 1970 by Winston W. Royce, who wanted to convert a risky development process into a linear process that would lead to the desired software product.

The Waterfall model uses a linear approach, where you need to finish one phase before moving to another one. There is no going back, and every stage depends on the previous one.

Inflexibility is the main downside of the Waterfall process. Projects utilizing this SDLC model are easy to manage, but the fact that there is little to no room for revisions once a stage is finished makes fixing any problem challenging.

So, which is better, Agile or Waterfall?

Both models have pros and cons that you should consider. They can be used for both small and big projects. However, the Waterfall model implies challenges for changes to the project in later development phases. On the other hand, the Agile SDLC model is known for its flexibility. Changes can be made at any stage of the development process.

Read on to learn why companies choose the Agile software development life cycle.

Below, we provide a comparison table for Agile SDLC and traditional SDLCs.

	Agile SDLC Model	Traditional SDLC Model
Model principle	The model is very flexible and can easily adapt the project to the customers’ needs and expectations	Such models lack flexibility and it is challenging to implement changes in a project
Project size	It is suitable for projects of all sizes - from small to large-scale. All can benefit from the flexible Agile SDLC model	It can be used for all types of projects. However, it makes little allowance for human errors and changes in development later are challenging
Success measurement	Successful work is measured by the delivered working software	Success is evaluated by conformity to the original plan
Adaptability	The changes are welcomed and accepted at any stage of project development	It is challenging to accept changes later on in the development process
Documentation	Agile doesn’t require a lot of documentation	Traditional SDLC models require intensive documentation
Iteration cycles	Has many iteration cycles – as many as needed for the product	The number of iterations is limited
Original planning	There is minimal planning required in the pre-development phase, as any changes can be made later on in the development process	Planning should be completed before the development starts, as changes are difficult to make in later stages of development

Agile SDLC Model: Main Underlying Processes

Agile SDLC was created to streamline the development process and provide users with timely and frequent software updates. In this chapter of our article we will talk about the main processes behind the Agile software development life cycle and how to make good use of them.

Agile SDLC: 12 Agile Principles that Shape the Agile Model

The Main Principles of Agile Manifesto

When the Agile Manifesto was released in 2001, the authors laid the foundation for Agile SDLC. Below, you will find out what the Agile Manifesto is and what the 12 principles of Agile are.

1. SDLC sets customer satisfaction as the highest priority. Customer satisfaction is achieved by early and continuous delivery of software that meets the requirements of users.
2. Agile SDLC welcomes changes, even if they are needed late in the development process. Rather than sticking to an original and sturdy plan, Agile provides flexibility that software development companies can use to respond to changes in the market and make the software competitive by catering to the needs of users.
3. Agile SDLC delivers value to customers by quickly releasing updated software with new working features. Rather than concentrating on one big update, which could require half a year to develop, Agile methodology provides new software in small chunks. It takes weeks, rather than months, to develop new features and increase the value of the product.
4. In Agile SDLC, rapid changes are not only normal, but also welcomed. The methodology keeps documentations lightweight and the need arises for constant collaboration between the development team and business people. This approach helps to keep everyone within the team up-to-date on the current state of events.
5. Projects are built around motivated developers and team members. Agile SDLC advocates for the ability to choose what jobs to take on based on personal interests and skills. Instead of external management and micromanagement, teams rely on self-organization.
6. The highest value in the Agile software development life cycle is placed on face-to-face conversations. This is considered to be the most efficient way to convey information. Pair programming is also widely used to transfer skills and improve communication within the development team.
7. Agile teams don’t measure progress by the number of working hours and sleepless nights spent at work. With the Agile development model, the ultimate progress is measured by working software releases.
8. The Agile software development life cycle promotes sustainable project development. Regardless of situations and circumstances, the development team should maintain a constant pace. This sort of approach helps to avoid working at unsociable hours.
9. The Agile team regularly reflects on its effectiveness and finds new ways to become more efficient.
10. Self-organizing teams know better how to build an architecture, design and develop software – not a project manager or any other person in a managerial position.
11. Agile project management methodology utilizes the Pareto principle, widely known as the 80/20 rule, but in a different manner. The traditional Pareto approach says that 80% of the result comes from 20% effort. Agile SDLC encourages developers to deliver 80% of product in just 20% of the time. Challenging, isn’t it? This can be achieved by focusing on essential parts of the software that bring real value to customers and the project.
12. Being Agile means being flexible. This means you need to quickly adapt to new circumstances regardless of the stage your project is on. You need to be prepared for the fact that sometimes, while you are developing a new feature, customer expectations change.

These are the 12 main pillars the Agile SDLC model relies upon. If you are considering moving to Agile SDLC, be ready to follow the principles described above.

The Main Phases of Agile Workflow

So, what are the steps in Agile methodology? Just like any other SDLC methodology, Agile SDLC consists of various steps. The main purpose of every step is to bring the team closer to the final result as soon as possible and to release new software just as quickly.

The Main Phases of Agile Workflow

Typical Agile workflow is comprised of the following steps:

1. Concept – in the first stage of Agile SDLC, the Agile team makes the overall project evaluation, where the team provides business analysis services. This is where the team proves or rejects a hypothesis about business benefit, estimates how much time the project will require, and identifies what resources might be needed later on in development.
2. Inception – after the concept stage comes the phase wherein the laying of a financial foundation occurs and primary team members are identified.
3. Iteration/Construction – during this phase, the team works on delivering working software. It is developed based on iteration requirements and feedback, and is changed and improved. This phase is divided into multiple timeframes (sprints).
4. Release – this process includes QA testing, user testing, documentation creation, and the release of an iteration into the market.
5. Production – the ongoing software support.
6. Retirement – is the final, and self-explanatory, Agile SDLC phase. Here, the development team stops supporting released software and notifies customers about it.

A software development company may have a few projects in development in different stages and with a variety of business needs.

Iteration Process as the Basis of Agile SDLC

The Iterative approach underlies the whole Agile software development life cycle. This process can be compared to a puzzle – to get the whole picture, you have to piece the parts together. The result of each iteration is the next piece of software and may be working software, some element, feature, documentation, etc. Iteration is repeated until the final product is completed and delivered to customers.

Iterative development can also be divided into the following phases:

• Requirements – development team defines the requirements for current iteration based on feedback from customers, business owners, and the whole project plan
• Development – the identified requirements are used to design and develop software
• Testing – the software is tested and documentation is created
• Delivery – software is released
• Feedback – the development team gathers feedback from users (both internal and external) and uses it for further requirement definition

The whole iterative process looks like a loop, where all steps are repeated, until all requirements in the product backlog are met. Repetitiveness defines the Agile SDLC.

Agile SDLC Model: The Pros and Cons You Should Consider

Advantages and Disadvantages of Agile SDLC Model

Now that you know the basics of Agile SDLC, it is time to look at its advantages and disadvantages and find out which projects would benefit from it the most.

When choosing Agile SDLC for your next project, consider the following factors:

• The Agile SDLC model allows teams to be more flexible and to implement changes more quickly
• Products get to market faster and users don’t have to wait long for new features and updates
• The Agile software development life cycle provides the necessary conditions for better communication with users and product owners. As a result, the development team releases only the functionality that customers really need and use.
• Functionality is rapidly developed and can be demonstrated at different stages of this process.
• Customer satisfaction is higher, as every sprint brings them updated software with a new working feature.
• Changes in the requirements are accepted even in the late stages of the development process.

At the same time, the Agile software development life cycle is not without its drawbacks:

• It is hard to predict what the final product will look like. As customers greatly influence the project and it is built and developed based on their feedback, no one knows how much time is needed to finish it and what resources might be required throughout the whole project lifecycle.
• As mentioned, extensive documentation is not a strong suit of Agile software development life cycle. If and when a need arises to transfer a project to a new team, lack of documentation makes the process quite challenging.
• Any product heavily depends on user behavior and iteration. If users are not clear in what they want, this may lead developers to the wrong conclusions and, as a result, to unnecessary changes in functionality.

Below, you can see a comparison table that explains where it is better to use the Agile SDLC model and what projects would benefit from the traditional SDLC methodology.

	Agile SDLC	Traditional SDLC
Requirement	Requirements are not clear and may change any stage in the development process	Requirements are clear and won’t change after the project has entered the development stage
Project and team sizeText	Project is small to medium in size and the team required is the same	Project is big as is the team
Planning	Planning heavily depends on feedback	Planning is documented
Refactoring	Refactoring is not expensive and can be easily performed	Refactoring is always expensive and challenging
Project architecture	Architecture remains flexible throughout the whole development process	Architecture is made as per current and further requirement
Risks	Unknown risks may occur at any stage of project development. This can impact the project greatly	The risks are well-known from the preparation stage, and the project is ready for them

Making Agile SDLC Work for You

Agile SDLC is a great solution for companies that need to release parts of software quickly and painlessly adjust to changes in requirements. The main secret of an efficient Agile SDLC process is constant collaboration and feedback sharing. Here is some advice on how to make the Agile software development life cycle model work for your company.

• Make daily meetings a part of your working routine. You will be able to hold workers accountable, create open communication between team members, track the progress of the iterations, and help move the process forward.
• After each iteration stage, demonstrate the final result. This is a great way to motivate team members and show that the input they provide matters.
• Collect and share feedback. Before the next iteration stage, share the collected feedback with the whole team to show an overview of the direction the project is going in. Don’t keep team members in the dark regarding the feedback from customers and product owners.
• Welcome changes regardless of the project stage, and even if they contradict with the original plan. Always remain flexible and open.
• Only make changes that will improve your product. Remember, after each iteration the software must become better and better.

Agile SDLC: Is it Suitable for Your Next Project?

Now that you know the main pros and cons of Agile SDLC, it is time to make your decision. It is vital to implement this software development approach only after your software development company or partner is sure that the project will benefit.

Agile SDLC is a great solution for startups, as the software market is highly competitive and you can score big success only by staying flexible, open to customer feedback, and ready to fundamentally change the path for your project.

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