SDLC Methodologies

Introduction to SDLC Methodologies

SDLC Methodologies are a standard procedure or a method followed by the software industry to describe the way to defining, building, implementing, develop an application and it follows the software development life cycle(SDLC) process. It is also known as a blueprint for designing software. Depending on the project, we choose an appropriate methodology to develop it and it upgrades the quality of software and the Software development process. The software methodology is a part of software engineering, to develop a software application. It provides guidelines to develop an application.

Popular SDLC Methodologies

There are several types of SDLC methodologies or models, but here we discuss some popular SDLC Methodologies, such as:

1. Fish Model

It is a time consuming and expensive SDLC model. Here both verification and validation are done parallel by the different teams.

It looks like fish so the model name shows the Fish model. In this model first, we go for Project Initiation Node (PIN) i.e. service level agreement would be signed for the starting of the project. Then the requirements are gathering from the client and analyze it, to prepare SRS (Software Requirement Specifications).In every step, we go for a review of the process i.e. verification. After that, we go for coding, Integration of module, acceptance, release, and maintenance of the development. For this process, we go for each level testing i.e. validation.

Advantages:

• It provides a high-quality software product.
• It is mostly used for secured projects.

Disadvantages:

• It is a time-consuming process to develop the product.
• It is expensive to process.

2. Waterfall Model

It is a rigid model, where requirements are fixed. So it is called the Sequential model. Here, until one phase is completed, we can’t go for the next phase.

In this model, after coding the planning, preparation and execution of the test are possible. So that is rigid and has a bottleneck activity of testing. (Less time for testing).

Advantages:

• It is a straight model and simple.
• It is easy to implement.

Disadvantages:

• 100% requirements are needed at the beginning of the project and no change later.
• Testing could become a bottleneck activity.
• Late Validation.

3. V Model

It is also called the Overlapping model. In this model, every phase we have test preparation & planning is done simultaneously, after coding we go for execution.

Advantages:

• It produces a high quality of the product.
• The testing process started early.

Disadvantages:

• 100% requirements are needed at the beginning of the project and no change later.
• It is a time consuming and expensive process.
• Late Validation.

4. RAD Model

It stands for Rapid Application Development. In waterfall and V-model, one cycle of SDLC is required to complete the entire project, but in this model, multiple cycles of SDLC is required to complete the entire project. Here the project is broken down into the number of releases and for each release, there is one cycle of SDLC.So it is also called the Iterative model. In every release, the number of requirements should be the same. After all the releases are completed, then integrate it and go for integration testing. One module or release is completer then show to the client, keep aside i.e. without release. It overcomes all the problems of waterfall & V-model.

Advantages:

• We don’t need 100% requirements at the beginning of the project.
• Testing is not a bottleneck activity.
• No late Validation by the client.

Disadvantages:

• It is a complex model.
• Late return on investment i.e. client can’t use the software even after complete earlier.

5. Incremental Model

It is also known as the Spiral model. In this methodology the project is broken down into different releases, at the end of each release, we show to the client, get it to approve and release the basic version of the software product. In this model, the testing process is complicated and takes much time as release version increases. So it is incremental in nature.

Requirements	Requirements	Requirements	Requirements
Analysis	Analysis	Analysis	Analysis
Design	Design	Design	Design
Coding	Coding	Coding	Coding
Testing	Testing	Testing	Testing
Release  Version 1.1
	Release  Version 1.2
		Release  Version 1.3
			Release  Version 1.4

Advantages:

• Early Return of Investment (ROI).
• The client can start to use the basic version of the software.

Disadvantages:

• It is a complex model.
• Time-consuming Testing process.
• Risk of regression is more (side effect)

6. Agile Model

Nowadays this model is mostly preferred by software organizations to develop the application. It is the combination of the Iterative and Incremental model. Every release is broken into different small parts is called sprint and each sprint having one cycle of SDLC. The number of requirements should be varying in every sprint, at the last sprint we integrate the entire sprint and go for integration testing. For each sprint, there is a time limit (2 – 4 weeks) to complete. It is also known as an adaptive model.

Advantages:

• It can deliver frequently and satisfy the client or customer.
• Continuous attention for sustainable development.
• The client can change or add the requirements at any stage of development.
• It deals with self-organizing teams to work together.
• It helps customer collaboration and responding to change.

Disadvantages:

• It is an expensive model.
• For a small project, it is not useful.

Conclusion

In this article, we discuss some popular SDLC methodologies briefly. Similarly, there are other SDLC methodologies like Lean model, DevOps model, Big Bang Model, etc. the selection of appropriate SDLC methodology for developing a software application is very important. The most popular SDLC methodology is Agile model.

Recommended Articles

This is a guide to SDLC Methodologies. Here we discuss the Introduction to SDLC Methodologies like Fish Model, RAD  Model, Waterfall Model, etc. along with Advantages and Disadvantages. You can also go through our other suggested articles to learn more –

1. SDLC vs STLC
2. What is Agile Testing?
3. SDLC vs Agile
4. SDLC Interview Questions