Spiral Model, advantages and disadvantages of spiral model in software engineering

Last modified on May 26th, 2018 at 2:05 pm

Spiral Model, advantages and disadvantages of the spiral model in software engineering

In this tutorial we will try to get the answer to the following questions;

What is spiral software model?
What are phases of the spiral model?
When to use spiral model?
What are advantages and disadvantages of the spiral model?

What is a spiral model?

The spiral model is a combination of waterfall, incremental, iterative and prototype model. It is mostly used for big projects where continuous changes are required.

Phases of spiral model:

Planning
Risk analysis
Engineering and Construction
Evaluation

Phase	Activities	Deliverable
Planning	≡ Requirement gathering ≡ Requirement analysis ≡ Requirement specification ≡ Requirement negotiation ≡ Requirement modeling ≡ Requirement Management	Software Requirement Specification document (SRS)
Risk Analysis	≡ Risk identification ≡ Prioritization of risk ≡ Risk reduction (Mitigation) ≡ Risk impact reduction ≡ Risk monitoring	Risk detailed document
Engineering	≡ Development ≡ Testing	≡ Code ≡ Test cases document, Test report document ≡ Fault report document
Evaluation	≡ Initial Validation by stakeholders ≡ Final Validation by customer	Evaluation report document

What are advantages of the spiral model?

≡ Ensure risk reduction

≡ Useful for large projects

≡ Changes can be handled in next iteration/loop.

≡ Most suitable for real-time systems

What are disadvantages of the spiral model?

≡ Expert required for risk reduction

≡ More costly

≡ Not suitable for small projects

≡ Project duration can be infinite because of its spiral behavior.

≡ Project cost can be infinite because of its spiral behavior

≡ Documentation can be very large

≡ Not suitable for the projects with low risk

When to use spiral model?

≡ When risk is medium or high

≡ When software is to be used in very sensitive and dangerous environment.

≡ For real-time systems

≡ For large projects

≡ When requirements are not clear

≡ When changes in the software can be expected at any time.