When a software or application is developed there are huge chances that it has bugs or defects and it might create issues for the end-user. So it’s necessary for software or applications to get through various stages of development from functional to non-functional as per Project requirements.

In the present time there are various types of models available in the industry that one can use as per requirements. But remember that models that are used in the software development process has its own pros & cons. So choose a model based on project needs.

Let’s dig into it and gather the details about the different software testing models in the following sequence.

Waterfall Model

The waterfall model aka The linear sequential life cycle model. The waterfall model has different stages and every stage needs to be completed before the next stages can start, and there is no overlapping in the stage.

The following phases are:-

Requirement gathering & Analysis.
System design & documentation.
Implementation.
Testing & Integration.
Maintenance.

When to Use:-

Probably when the project is short, static, stable, and well-documented.

Pros:-

Simple to use, implemented, and understandable.
Fewer resources needed.

Cons:-

Difficult to change or update the requirements.
Once you move to the next phase, you can’t make changes to the previous phase.
To start the next phase, you need to wait until the previous step is finished.

V-Model

V-model means verification and validation model. Just as the linear sequential life cycle model, here we also need to complete every stage before the next stage starts. Testing of the product is planned to be in tune with the stage of development in the V-model.

When to Use:-

Small or medium-level projects where requirements are clearly defined and fixed.
When you have enough resources with needed technical expertise.

Pro:-

Testing activity like planning or test designing happens well before coding. This saves a lot of time.
Perfect for small projects where requirements are easily intelligible.

Cons:-

Very strict and least flexible.
In case any changes happen midway, we need to update the test documents along with the required documents.

Agile Model

The agile model focuses more on workability and customer satisfaction through the rapid delivery of working software products. We can say that an agile model is a mixture of iterative and incremental models. We can develop solutions by collaborating with different cross-functional terms. There is one framework called scrum by which we can implement agile. Scrum has three specific roles…, Product Owner (PO), Scrum Master (SM), and development team of programmer & testers. These all work together in constant time duration which are called Sprints.

When to Use:-

Mostly used for mid-level and low-risk projects.

Pros:-

Minimum resources and no planning documentation are required.
By providing fast and continuous development of delivery, it ensures customer satisfaction.
Functionality can be developed quickly and demonstrated.

Cons:-

There is high individual dependency due to minimum documentation.
It’s not easy to assess the effort required at the early stage of the cycle for large and complicated software development cases.

Spiral Model

Spiral Model is a mixture of iterative development process model and waterfall model with high attention on risk analysis. Here are 4 phases in the “spiral models” which are:-

Planning
Evaluation
Risk Analysis
Engineering

Gather the details and apply risk assessment at the base level, and each spiral builds on it.

When to Use:-

Use in medium to high-risk long-term projects.
When budget constraints and risk analysis are important.

Pros:-

Software can be generated early in the cycle.
Great for large and complex systems.
Changing requirements can be accommodated.

Cons:-

Process becomes complicated.
It doesn’t work well on low-risk, easy projects.
Expensive model that also requires expertise in risk analysis.

Iterative Model

In this model requirements are divided into small modules and bulls. The process continues and allows a new version of the product for each cycle. This model goes through 4 phases which are, The requirements, Design, Implementation, and Testing phases. This process continues till the system is ready as per requirements.

When to use:-

The requirements are clear and understandable.
Use when there is a time-to-market constraint.
Projects in which new technologies will be used.

Pros:-

It is smooth to hold the risk as high-risk are completed first.
The progress is easy to perceptible.
Bugs and errors can be found earlier.

Cons:-

Not suitable for smaller projects.
Need much more management attention.
Required more resources.

Conclusion

There are so many methods in the software development life cycle [SDLC] and the methods we just discussed are not the end. Various methods have been introduced by experts in the industry, which change constantly as more efficient ways are discovered. Learn all these methods and then plan the SDLC according to your project requirements.

Software Testing Models