Waterfall V/S Agile Software Development Methodology

source: softwaretestinghelp

You need a full-fledged framework to structure the software development process? If you start with a software engineering project without considering which framework or model works best for you, you might land up with a messy output for your client. Even worse, you would not have a functional software at all.

In software engineering, software development life cycle of SDLC is a continuous process to guide the stages of software development. It is a procedure for planning, resource allocating, creating, testing, and deploying a software product, mobile applications, or web apps. A team can follow one of several SDLC models for their project.


Before we take a look over the two primary SDLC methodologies – Waterfall and Agile, let us understand the five main stages of an SDLC. No matter what method a team chooses, it has to follow these stages because they are incorporated into each SDLC methodology.

Five Stages of Software Development Life Cycle

1. Planning and Requirement Analysis – This phase starts with a formal discussion between the client and the working team. The team members of the project should understand the detailed definition of the system requirements. Next, planning takes place. The resource allocation, capacity planning, and team planning happen at this phase. All the stakeholders participate in this phase to plan the big
picture of the project.

2. Designing and Prototyping – Architecture designing of the entire project takes place at this phase. Pre-established patterns for software development and application architecture are used during the designing process. Architects design the whole project with the help of architecture frameworks.


All the stakeholders of the project sit together, and all the minute technical queries are answered. The technology, team loads, timelines, and budget are decided in this stage.

3. Software Development – The most critical phase, the development and programming phase of an SDLC, takes the longest time out of all the other stages. The software developers start with the actual programming and coding part. The front end designers start with the designing part. The output of this phase, functional software, should involve the active engagement of the client to ensure that their
requirements have been fulfilled.

4. Testing – The testing phase is one of the most important phases of an SDLC. A software engineering team would not be able to deliver quality software or mobile app without passing it through the testing stage. Several types of testing are done repeatedly until the functional software matches the expectations and requirements of the client. These methods ensure that the website or software works fine on various parameters like functionality, performance, load, security, etc.


5. Deployment – The approved product is ready to use software or application as per the client’s needs. This needs to be handed over to the client. In this phase, the technical support team gets involved and provides support for the implementation of the software.

Moreover, the technical support team is also responsible for supporting the client in providing time-to-time maintenance of the software and updates from the development team to keep the product up to date.

Waterfall SDLC Model

The waterfall SDLC model is a traditional and one of the oldest SDLC models. It is a sequential model in which all the phases of the SDLC are observed one after the other. In other words, the working team doesn’t move to stage two unless stage one is completed and approved, and so on.


Advantages of the Waterfall Model

1. The waterfall model is the most straightforward model to understand and implement in a project.

2. It is easily manageable. This is because each stage starts only once the previous one finishes. Moreover, deliverables of each stage are clearly defined, making it easy for every team member to focus on the timely delivery of their assignment.

3. It ensures faster and timely delivery of the project.

4. It works well for smaller projects because the requirements are easier to understand and implement.


5. Dependency on the client during the project development and testing phases is almost negligible.

6. It is easy to manage a waterfall model project if the teams are more likely to change frequently. This is because everyone in the group knows the status of the project, and thus knowledge transfer for the shifting team member isn’t a tough and long job.

Disadvantages of Waterfall Model

1. If the requirements are not clear from stage one, the waterfall model becomes quite expensive and inefficient.

2. It is impractical for large projects.

3. Testing starts only after the development ends. Hence, debugging some major bugs can make the project development costs.


Agile SDLC Model

In an agile model, the whole project is divided into numerous small projects called “sprints.” These sprints have a shorter timeline (usually within a week or two). Hence, all five phases of SDLC are almost concurrent and take place for every sprint. To simplify, we can say that each sprint follows the waterfall model several times before it is delivered to the client.

Advantages of Agile Model

1. The ongoing testing of the sprints ensures the timely correction of bugs in the system.

2. Continuous involvement of the developers, testers, managers, architects, business analysts, and client guarantees excellent quality of each deliverable.

3. Due to shorter timelines, the team works hard and efficiently and are self-motivated.

4. Timely debugging and delivery ensure quality that further makes the whole project cheaper by avoiding confusion at the later stages.

5. It is fit for larger projects.

Disadvantages of Agile Model

1. It is not useful for smaller projects.

2. Daily or weekly meetings with the client need decision-making experts always.

3. Implementation of the agile model is difficult, and the training and initial implementation might be costly.

As said, the Waterfall model is perfect for a small project where requirements are easy to understand and mostly fixed. This is because the waterfall model doesn’t allow much time and flexibility to provide last-minute changes.

On the other hand, software engineering teams should choose the Agile model for larger projects. This is because; the needs of the client are quite likely to change frequently for a huge project, and Agile can accommodate those changes without any difficulty or extra charges.