What are Popular SDLC Models & Methodologies?

Software development is all about finding the right balance between time, cost, and quality. When done correctly, it can transform a small business into a well-oiled machine. However, when done incorrectly, it can have the opposite effect. In this blog post, we’ll take a look at some of the most common software development methodologies and models. Let’s get started!

What is a SDLC model and list Most Used SDLC models?

SDLC models are a series of sequential steps taken during the software development process. SDLC (Software Development Lifecycle) models are a strategic approach for software development, starting with a vision and goals, and following through with planning, analysis, design, construction, testing, and maintenance of a product.

There are different types of SDLC models that follow the activities related to a software product’s development. Each step is defined as a stage and each stage can have a number of requirements or deliverables. The most popular models are Agile, Waterfall, and Spiral. Companies adopt these models according to their requirements, goals, and available resources.

List of Most Used and Popular SDLC Models:

1. Waterfall model
2. Iterative model
3. Spiral model
4. V-shaped model
5. Agile model

Waterfall Model:

A phased approach is used in this model. The first phase begins immediately after you start the model and includes building the necessary infrastructure. The development is divided into sequential phases, one after the other. Each phase is independent, and there is no feedback loop between the phases. The waterfall model allows work to start on new products or features during the construction phase. When you finish a task, a new task begins.

V-shaped SDLC model:

The testing and development stages of the software development lifecycle are interwoven and synchronized. The testing stage corresponds to a certain development phase, and the testing process takes place at the same time as development.

Waterfall development means that there’s a strict plan for each phase and once a certain milestone is achieved, the next phase begins. The stages in a project are often organized as a pyramid of tasks. Each stage has a deliverable at the end, and you work from bottom to top. Mistakes are always detected before they become critical.

Iterative Model:

This model follows iterative development. This starts when analysis is done. After analysis, we get back to the analysis phase, and again start development. This goes on for a number of times till we get the solution. This is a very useful. In this model, development is done in phases. After completing each phase, development again starts in the next phase. This model is flexible.

Spiral model:

It’s not an exaggeration to say that it is the combination of the Iterative and Waterfall SDLC models with a strong emphasis on the risk analysis

The spiral model suggests that there is always a right moment to take the next step. There’s not much evidence that the preliminary set timeframes are the correct resolution to this issue.

The shift to the next stage happens according to plan, even if the work on the previous step isn’t done yet. This is an effective method used by Amazon.com to introduce products based on the statistical data obtained from the customers in the previous project.

Agile SDLC Model:

Agile is a method of software development where the tasks are divided to time boxes (small time frames) to deliver specific features for a release.

You are delivering working software to your customers on a regular basis. Iterations are the main unit of work in Scrum. The team will define the amount of work they need to perform in a certain time frame.

Waterfall model: How it works and differs from other models.

It is a software development methodology, which can divide the entire software development process into different phases. It first divides the process into four groups: initiation, analysis, design, and implementation.

Initiation: It is the process of planning or deciding to begin a software project. The initiation phase involves deciding the type of software to be developed, the information needed for the program, and cost estimates. The initiation phase also involves selecting the project managers, team leaders, and key developers.

Analysis: It is the process of selecting tools and techniques, preparing them, and arranging them to execute the requirements. The analysis phase involves reviewing the system requirements and agreeing on the approach for executing the requirements. During this phase, an analysis of risks and alternative approaches is also conducted.

Design: This phase involves defining the high-level design of a system and determining the system structure and functions. In this phase, components, modules, and interfaces are identified. The interfaces with existing systems are also considered.

Implementation: This phase involves generating code for the software. The implementation phase can be divided into four sub-phases: coding, unit testing, system testing, and system integration.

Agile SDLC model: How it works and differs from other models?

Agile SDLC is a software development model that is more flexible and easier on management than traditional approaches. It is meant to facilitate rapid development and deployment of new products and services, without sacrificing quality.

It focuses on breaking up large projects into a series of smaller, more manageable tasks. Moreover, It treats each task like a project in itself, with clearly defined objectives, timeline, and deliverables. However, unlike traditional models, it does not insist on strict adherence to traditional processes like waterfall or incremental models. Agile SDLC has many advantages over traditional approaches, including:

Better planning and better control:

Agile SDLC promote greater planning control, with sequential tasks slotted into a well-planned out schedule. With traditional models, it’s more difficult to predict outcomes.

Continuous development:

It promotes continuous development through iteration and incremental releases. This allows you to test, modify, and refine products and services on the fly, rather than wait for the design and development stages to be fully completed before starting work on the next stage.

Faster development:

It provides faster development by breaking down large projects into smaller tasks, which smaller teams can complete. This allows for faster turnaround (and potentially faster releases), and the ability to make changes as new development is undertaken.

Better communication and collaboration:

Agile SDLC Model enables better communication between teams, allowing developers to identify potential issues or problems early-on and deal with them before they become real problems. It also helps facilitate better communication between business stakeholders and developers, which can speed up the development and testing process.

There are many different ways to apply Agile SDLC in your organization. Each approach differs in terms of complexity and implementation.

Spiral Model SDLC: How it works and differs from other models?

A Spiral Model SDLC is a phased model that allows for iterative development processes with adaptive planning, risk management, reviews and testing. This methodology allows for earlier releases of software, reduces cost, and improves quality.

The Spiral Model SDLC was developed by Barry Boehm in 1986. It was designed to organize the software solutions into phases.

The Spiral Model SDLC is a seven-step process:

1. Iterative Development
2. Detailed Design
3. Coding
4. Testing
5. Reviews
6. Refactoring
7. and last but not least Deployment

V Model SDLC: How it works and differs from other models?

V model SDLC is a project management model that is used for software development. It matches characteristics with waterfall model. While having the complete requirement analysis done, it is suitable for large projects. However, it is not suitable for repetitive projects since the requirements analysis is time-consuming.

Some of the benefits of V model SDLC are as follows:

Reusability: Under V model SDLC, software modules developed can be reused in different projects.

Iterative Approach: In V model SDLC, we divide the entire software into smaller modules and divide each module into iterations. In each iterative step, testing is done. Thus, it enables us to test each module completely before building the final software.

Incremental development: In V model, we divide the entire software into smaller modules and divide each module into iterations.

Testing: Each module can be done in an incremental way. Thus, it enables us to test each module completely before building the final software.

Big Bang Model in SDLC

Big Bang Model SDLC is a software development methodology that is based on incremental development. Compared to other types of SDLC model, this model has fewer phases, fewer methods, and fewer documents. It reduces the amount of time and effort required to deliver the product to the customer. This model is also suitable for projects that require a quick start.

The main features of this model are as follows:

• The development cycle starts with the delivery of user requirements to the development team.
• It creates the system design document (SDD) using the requirements.
• The detailed design (DD) is based on the SDD.
• Staging environment is created based on the DD.
• Production environment is created based on the DD.
• The development team fixes any defects found.
• Team delivers the final version of application to the customer.

Advantages of this model are as follows:

This methodology is suitable for projects that need a quick start

• This model requires little effort, as you can use it for smaller projects.
• It can be implemented by one person alone.
• This model is suitable for projects with small teams.
• This model is suitable for projects that require ongoing development.

Iterative Model SDLC: How it works and Difference between other models?

The ‘ITERATIVE SDLC model is an iterative process that pushes each work package through the SDLC quickly without waiting till completion of other work packages. Instead of moving down the product life cycle in a linear fashion, an iterative model allows products to be developed from the customer’s perspective, rather than from the provider’s perspective.

It is a relatively new SDLC technique. The normal SDLC models are Spiral and Waterfall. While Spiral model allows development to be done in 2 to 3 phases, the iterative model allows development to be done in 3 to 4 phases, each phase being independent from each other.

The incremental model allows all phases of SDLC to be performed without waiting till completion of other phases. This allows a product to be developed much faster.

One of the main differences between the iterative model and other SDLC models is the amount of time that is required to develop the same product. In waterfall model, all phases of SDLC are completed and completed development takes a considerable amount of time. The waterfall model focuses on the development of a product.

In spiral model, 1 or more phases are started at a time and work is completed in each phase. When development in all phases has been completed, a final product is developed. The spiral model focuses on the development of product.

In iterative model, development is done in each phase in parallel. Development in 1 phase is started without waiting till completion of other phases. This allows a product to be developed much faster.

Another advantage of iterative model is that the product under development is always in customers hands. Product is not completed only when development in all phases has been completed. The iterative model has been used successfully in many projects related to small scale software developments.

What is SDLC Threat Modeling? Working and Benefits

SDLC Threat modeling is a technique that helps identify and mitigate security vulnerabilities within a software system. It helps with software development life cycle, responding to vulnerabilities and threats early in the life cycle.

Basically, it is an activity that will help you understand potential threats to the system through different security vulnerabilities. It helps better understand threats that can impact your application.

Moreover, it also provides a way to see weaknesses in security before implementation. This helps you develop an understanding of potential threats and vulnerabilities. These vulnerabilities and threats can be categorized by severity, probability, and impact.

Threat modeling in SDLC is a collaborative activity that helps identify potential threats to the system through different security vulnerabilities. Threat modeling helps develop a better understanding of threats that can impact your application.

It is an excellent way to see weaknesses in security before implementation. This helps you develop an understanding of potential threats and vulnerabilities. These vulnerabilities and threats can be categorized by severity, probability, and impact.

Hybrid Model in SDLC

There are two types of software development models, they are waterfall model and Agile model.

Waterfall Model:

The waterfall model is also known as the sequential development process model. It is comprised of three basic phases, which are initiation, analysis, and test development. At the end of the analysis phase, the document is fully completed, and the project is ready to be completed.

The waterfall model is very rigid, which means that there is little flexibility. It is a linear process, which begins with one phase and ends with another. This sequence must be followed in order to successfully complete the project. The waterfall model can become very inefficient, especially if there are several changes to the project.

Agile Model:

The agile model is also known as SCRUM model. It is an iterative and incremental process, which means there are several iterations and improvements. This model is created to provide flexibility and efficiency. There are several iterations throughout the development process, which allows the team to have flexibility.

The agile model is very effective, particularly in large projects. It also ensures that there are no defects or bugs in the software. The agile model helps the team to focus on the project and work more efficiently. The iteration model allows the teams to adapt to any changes or requirements in each stage: planning, development, testing, and implementation.

Incremental model in SDLC:

The incremental model in SDLC consists of few stages including planning, analysis, coding and testing. These stages are iteratively performed and each step acts as a building block of final deliverable. The incremental model in SDLC includes 5W1H analysis, developing use cases, designing solution, coding and testing.

It is faster as compared to traditional waterfall model. Moreover, it delivers tangible products at the end of each stage. It is well suited for small projects.

Lean SDLC Model:

The Lean development model generally starts from the stage where business issues are identified and prioritized, the product requirements are gathered and prioritized (which may come from the product realization process), and the product is built.

The Lean model is maintained until the product reaches the market (or until the product has been decommissioned).

Fountain SDLC model:

The Fountain Model is an attempt to represent the software development life cycle. Software is one of those fields where coding can begin before the design is entirely mature.

Incremental changes to an implementation during the design stage are usually not very expensive because they’re not particularly tangible, but it depends on what the changes involve, such as new features or a different color scheme.

Expert programmers, particularly those who work with an imperative language such as C, Java, or C++, tend to use a programming language to describe their design.

Final Thoughts:

So, you might be wondering which software development method is best for you? The answer to this question depends on the specific needs of your business. Hopefully, this overview has given you some valuable insight into SDLC models and software development lifecycle methodologies.