Spiral Model

Why spiral model is used these days? What are advantages of using Spiral Model?

The spiral model is a software development process combining elements of both design and prototyping-in-stages, in an effort to combine advantages of top-down and bottom-up concepts. The spiral model is used most often in large projects. For smaller projects, the concept of agile software development is becoming a viable alternative. The US military has adopted the spiral model for its Future Combat Systems program.

[U]Advantages:[/U]Estimates (i.e. budget, schedule, etc.) get more realistic as work progresses, because important issues are discovered earlier.

It is more able to cope with the (nearly inevitable) changes that software development generally entails.
Software engineers (who can get restless with protracted design processes) can get their hands in and start working on a project earlier

For more details Search Wikipedia.org . You will get info. about V-Model also, which is very interesting.
And yes,these are very popular interview questions. Not for just the sake of interview but for getting global idea of methodologies is always good.

Most commonly V-model is used not the spiral model.

Spiral model is used when our customer have passions and he can invest more and can take active participate during project life cycle.

What Member" spd15" have told is 100% true. Spiral model will be adopted most likely for big projects which has several builds and releases. This ensures in continuous process of finding the bugs in Regression environment. And the fixes happens in consecutive builds. Spiral model helps in each and every stage of SDLC to produce better results in the form of max. error free application delivery. Here one important point to be noted is when we are working on spiral model, Tester and Developer works closely to associate and fix the bugs simultaneously whenever the build happens.

Hope you got answer.

Thanks & Regards

Arun