What is SDLC?

Photo of author

By Vijay Singh Khatri

As a software developer, you must have come across the term SDLC (Software Development Life Cycle) several times in your projects. SDLC is a structured process that software developers follow to provide high-quality, low-cost software in the shortest possible time. The main objective of the implementation of SDLC is to provide clients with superior software which firmly stands on their expectations and demands.

The truth about the software development market is that everyone wants to get their hands on the product as soon as possible. For that, developers need to be innovative in their production process. Thus, if a developer chooses the wrong SDLC model, the development cycle could be delayed, and instead of streamlining the whole process of development, it becomes more tedious.

But, don’t worry, we got you covered. This article will talk about different types of models that a software developer can consider, and also provide information on where a specific SDLC model can be used.

What is Software Development?

When anyone steps into the IT field, their main goal is to work as a software developer as it is the core job and pays well at the end of the month. Software development is more than just writing code to create software. The task involves a planned initiative with several steps and stages that leads to the development of operational software. Thus, software development means a process with a set of activities that need to be performed in a particular manner to create computer software products. These activities range from designing, development, testing, to deployment of the software.

Software is more like a set of instructions that tells the computer what it needs to do to perform any given task. In addition to this, the software is entirely independent of the hardware end. Here’s a general trivia for our readers, the very first software was developed in 1960. From 1960 to now, software development has come a long way, and the most common form of software development approach is agile development.

There are four basic software development categories: application development, system software development, development tools, and embedded software development. Each of these categories requires a different set of developers with specific skill sets.

Benefits of SDLC

Clear RoadMap For Project

Sometimes, an individual team member doesn’t know why he’s making any particular element of the software and how it will be used in the software. As a result, the development of subparts proceeds without keeping the end goal in mind, resulting in integration issues in the end. With SDLC, every employee in the company who is on the project will be on the same page. They will know what they have to do and its importance to the whole development cycle. The goals will be set upfront, and they will be set after all the parties of the development cycle agree on it.

When the final goal is clear, managers can provide a clear and realistic plan with an achievable deadline. On the other hand, the cost estimation and the resources required to finish the project will also have a clearer picture.

Change in Employee Won’t Affect the Development Speed

If someone from the team is not able to continue with the project, the development process won’t be affected. Every progress in SDLC is shared with other members of the team. As a result, if one does go away, a new employee can easily understand the work he needs to perform by the information which will be provided to him. Thus, he will have to face no complications to restart the work in no time.

Minimizes Errors & Roadblocks

If developers know the importance of their work, and how the finished product is going to work for the end-user, they will be able to find the best of the methods to develop that particular part of the software that is assigned to them. Also, when each team knows what the other team is working on, then this knowledge will help in building better communication between different teams. Moreover, with the increase in communication, the integration between different elements of the software will be much smoother and will have fewer issues.


The SDLC can be looped, meaning if the project manager finds that the feedback is not up to the level which he wanted. The team can start over that stage of the SDLC once again and come up with new solutions to make their work more efficient. The SDLC provides software developers with the flexibility of making changes at each stage of the project.

Thorough Testing

After each phase, there is a review and a testing part that needs to be done to proceed further. The SDLC comes with mandatory checks and balances so that the testing part is done with precision and seriousness.


Another great advantage of using SDLC is that at the end of each phase, you get a review of the project. This allows managers to track the progress and see if the development team is still on target or not. In addition to this, having the ability to get a review at the end of each phase will allow management to utilize their power of control over the development cycle in a better way.


SDLC’s main aim is to achieve the goals which are set by the product manager, and with its usage, the possibility of achieving that goal becomes more manageable. At the end of the SDLC, the goal is the delivery of a quality product to the end-users.

Difference between SDLC and Product Life Cycle

A lot of people confuse Software Development Life Cycle (SDLC) with Product Life Cycle (PLC). A project life cycle is a sequence of the phases from which the project has to go through from the very beginning to the very end. The projects are undertaken to provide products and services to the customer. Each phase of the product cycle should have one or more deliverables at the end. These deliverables are tangible and more often a verifiable product of the project. Moreover, a software development life cycle is a part of the product life cycle. Because software is the sub-part of the whole product, the software can be an entire product as well, but in most cases, the software is one of the sub-parts of a much bigger project which includes websites, mobile applications, a marketing campaign, etc.

Need of Different Types of SDLC Models

Different models are designed for a specific software development project, and each SDLC has its own set of advantages and disadvantages. As a result, a team has to decide which one is best according to their project and then work accordingly. For example, the waterfall model is used to develop Customer Relationship Management (CRM) software, supply chain management system, inventory management system, etc. The waterfall model is used in the development of this software because the project requirements were exact, and there were no uncertain requirements, which might ask for space for the addition of new features in the future. Thus, the waterfall model is the optimal SDLC approach in this case.

On the other hand, we have a spiral model, which is also considered to be a meta-model as it subsumes all the basic models along with the waterfall model. The spiral model is used in the development of mobile apps, as they need constant updates or patches to fix the issue. Also, spiral models can be used with budget constraints where the client doesn’t know all the requirements from the project and will ask developers to add new features after the initial release. In this case, the waterfall model can’t be used as it doesn’t leave any space for further addition or changes in the software. This is why we need different SDLC models for developing different sets of software.

Different Types of SDLC Models

Now that you know about the importance of having various SDLC models, let’s find out what are the different SDLC models, their advantages, and their use cases.

1. Waterfall Model

The Waterfall model was the first SDLC ever introduced. It is also known as a linear-sequential life cycle model. Due to the model being linear, it is pretty easy to understand and use. In this model, each phase has to be completed before the team members move to the next step as there is no overlapping of the different stages.

  • The waterfall model could be an excellent solution for a company that has multiple departments as it does allow departmentalization workflow and managerial control of the project.
  • It is the easiest SDLC to understand and implement.
  • Moreover, its management is easy because each phase has a specific set of deliverables and a review process, making the model more rigid.
  • Each stage has its set timeline, and the model follows one phase completion at a time format.
  • The waterfall model works great for small-scale projects where requirements are well defined from the beginning.
  • Each stage of development can be assigned its deadline so that the developed software can proceed further to the next step of the development, and the overall project can be completed on time.

The issue with the waterfall model is that once a particular phase is complete and the project moves on to the next stage then there is no going back. Even if a developer finds a problem related to the previous phase, it’s too late to go back and rectify the problem. Besides this, if a project is pretty complex, it is hard to determine its complete features and requirements at the beginning of the project. The testing stage of the waterfall model comes at the very end of a cycle. This makes it difficult to determine the problems that developers were able to uncover in the initial phases.

2. Iterative Model

Iterative means “evolving”, and this is the functioning of an iterative model. It starts with a basic implementation of the subset, which contains a specific set of software requirements and iteratively enhances the evolving versions until the entire system is implemented. At each new iteration, the software will have design modifications, and the addition of new functional capabilities.

The primary use of this development model is to create software using repeated cycles of development that last for a shorter duration of time. One significant difference between the iterative model and the waterfall model is that during the development phase, more than one iteration of an SDLC might be in progress alongside each other.

  • The working functionality can be developed at the early stage of the cycle. This helps developers to obtain results early and in a periodical manner.
  • It enables parallel development, and the progress of the project can easily be tracked.
  • Making changes in the scope and the requirements is easier and doesn’t affect the overall costing significantly.
  • Testing and debugging of errors is quick due to the implementation of smaller iterations.
  • The high-risk tasks can be performed first.
  • The operating time of iterative SDLC is less.
  • The iterative model is suitable for mission-critical projects where creating the best product for the client is a necessity.
  • Lastly, during the life cycle of the model, the software is developed by facilitating customer’s evaluation and the feedback of the product.

The iterative model has some downsides as well; for example, you are required to have more resources dedicated to a single project. In addition to this, the cost of changing the requirements of the project might not have much of an impact, but the model is not suitable for making these changes. There could be issues in designing the system architecture as not all the requirements were gathered at the start of the project.

3. Spiral Model

The spiral model is considered to be the best SDLC model as it comes with the support of risk handling. If we look at its diagrammatic representation, we can see it’s a spiral with many loops. There is no exact number of spirals as it can vary from project to project. Each loop of the spiral represents the phase of a software development process.

In the spiral model, the project manager has to dynamically determine the number of phases along with keeping the radius of the spiral in mind, which represents the costing related to the different stages of the project. Moreover, the spiral is divided into four quadrants. The functions of the quadrants are as follows:

  1. Determine the objectives of the project and identify the solution.
  2. Find out the risks and resolve them.
  3. Develop the next version of the product.
  4. Review the developed product and start planning for the next phase.
  • The first is how a spiral model is created to handle the unknown risks that could occur during the development cycle of a product. It has a risk analysis and risk managing measures deployed after every phase.
  • This model is best for more extensive projects that require multiple development cycles and testing.
  • Add-on changes in the requirement can be easily handled as the changes can be incorporated accurately using a spiral model.
  • A client can see the progress during each phase, and this model provides a working prototype at the initial stages. As a result, a client gets habituated with the software before the software is completely developed.

With great features comes bigger expenses. As a result, it is not recommended to use spiral models for small-scale projects. Also, complexity is a significant issue in the spiral model, resulting in companies having the best of the experienced developers to work on it because of too much dependency on risk analysis. As we have said, there is no estimation of phases (loops); thus, time estimation is pretty tricky. The spiral SDLC model is used in developing AAA gaming titles, mobile applications, etc.

4. V-Model

V-model works on two principles; the first one is verification and validation. In this model, each phase needs to be completed before the next phase of development can start. The design is much the same as the waterfall sequential processing. With each stage of development, the testing of the product for the same stage is also planned. The model should be used for the development of small- to medium-size projects where the requirements of the project are correctly defined. Moreover, when you have ample technical resources with the required technical experience, the V-model can be quite helpful.

The two core concepts of the V-model are defined below. Both these concepts start independently and parallel to each other. They combine as one during the later stages of the project because these stages are critical, and the teams need to be in close communication with each other.

Verification: This core concept involves a static analysis method in which the work done is reviewed without executing the code. It is used to find if the given requirements were met during the product development process.

Validation: In this part of the development, the operations involve both functional and non-functional dynamic analysis. Here the testing of the product is done by executing the code. The validation is done to determine whether the software meets the customer’s expectations once the development process for the particular phase is completed.

  • This SDLC is the most disciplined model, and each phase needs to be completed on a given timeline so that the next stage can start.
  • It’s a great SDLC model for small-scale projects where you know all the requirements beforehand from the client.
  • Moreover, the testing is done at each phase, so there’s no downward flow of the defects.

The only issue with the V-model is that it is pretty rigid and does not leave room for flexibility. Thus, if you want to add something to the requirements, it will be a complicated process for the development team. Also, no early prototypes are there for clients to see until the project reaches the implementation stage.

5. Big Bang Model

The Big Bang model of SDLC can be applicable where there is no specific process that a developer needs to follow to develop software. In this model, the process just starts with the money and the resources which are at present available to the team. The developed product could sometimes miss the requirements which the client has asked in the first place. In simpler words, the Big Bang model follows the most non-formal development steps and procedures that are followed by very little planning before the start of the project.

The requirements are understood and implemented on the project as they come. As a result, if there are any changes or additions in the functionality of the software, the underdeveloped system does not need to revamp the complete software.

  • The model is fundamental, and when you start working on it, there is little to no planning required. Thus, it’s easy to manage.
  • Unlike other SDLCs, the resources required here are quite a few, which makes the development task to be flexible for developers.
  • For new software engineers, this is the best way to learn about different tools and programming languages that can be used in software development.

The problem with the Big Bang model is that there is no planning required to start the project, which is what makes it quite risky. It’s not an ideal model for developing mid to large-scale projects. Moreover, if the requirements are not defined soon, the project can turn out to be quite expensive. This model surely gives developers the flexibility of working according to their own experience, but the uncertainty is the thing that makes it a tough choice to opt for.


So now you know the definition of SDLC, different types of SDLCs, and their benefits. SDLC is a vast topic, and it is constantly evolving as the technology used in it keeps on developing. Any new software developer who wants to kick-start their career in the field of development must get their hands on SDLC.

Leave a Comment