Difference between Waterfall Model and Spiral Model

The waterfall model and Spiral model are used in software development. Waterfall model is also known as the classical or linear model because it follows sequential stages while the spiral model does not follow the sequential stages it follows the evolutionary way. The amount of risk in the waterfall model is more as compared to the spiral model because the errors or risks are identified and refined after the completion of each stage.

What is Waterfall Model?

The waterfall model is a software development model used in the context of large, complex projects, typically in the field of information technology. It is characterized by a structured, sequential approach to project management and software development.

What is Spiral Model?

The Spiral Model is a Software Development Life Cycle (SDLC) model that provides a systematic and iterative approach to software development. In its diagrammatic representation, looks like a spiral with many loops. The exact number of loops of the spiral is unknown and can vary from project to project. Each loop of the spiral is called a phase of the software development process.

Difference between Spiral Model and Waterfall Model

There are some differences between these two models waterfall and spiral models which are given below:

Aspect Waterfall Model Spiral Model
Complexity The Waterfall model is simple and easy. The spiral model is a lot more complex.
Development Method The waterfall model works in a sequential method. While the spiral model works in the evolutionary method.
Risk Management In the waterfall model errors or risks are identified and rectified after the completion of stages. In the spiral model errors or risks are identified and rectified earlier.
Adoption The waterfall model is adopted by customers. While the spiral model is adopted by developers.
Project Size Suitability The waterfall model is applicable for small projects. While the Spiral model is used for large projects.
Planning In waterfall model requirements and early stage planning is necessary. While in spiral model requirements and early stage planning is necessary if required.
Flexibility to Change Flexibility to change in waterfall model is Difficult. Flexibility to change in spiral model is not Difficult.
Risk Level There is high amount risk in waterfall model. There is low amount risk in spiral model.
Cost Waterfall model is comparatively inexpensive. While cost of spiral model is very expensive.
Customer Involvement Customer involvement is minimum in Waterfall Model In the Spiral Model Customer involvement is high.
Maintenance It requires least maintenance. It requires typical maintenance.
Framework Type It is based on linear framework type. It is based on linear and iterative framework type.
Testing Testing is done after the coding phase in the development life cycle. Testing is done after the engineering phase in the development cycle.
Reusability Reusability is extremely unlikely. To a certain extent, reusability is possible.
Customer Control Customer control over the administrator is very limited. Customers have control over the administrator as compared to waterfall model.

Frequently Asked Questions related to Waterfall Model vs Spiral Model

What are the 4 phases of spiral model?

Four Phases of Spiral Model are:

  1. Planning
  2. Risk Analysis
  3. Engineering
  4. Evaluation

Is spiral model a SDLC?

Yes, the Spiral model is a type of Software Development Life Cycle (SDLC) model.

Is Scrum a spiral model?

No, Scrum is not a Spiral model. While both Scrum and the Spiral model are used for managing complex projects and share some similarities, such as iterative development and risk management, they are distinct methodologies with different frameworks and principles.