What are the things require to go for Agile?

1. The first step is to find suitable projects to try agile methods out with. Since agile methods are so fundamentally people-oriented, it's essential that you start with a team that wants to try and work in an agile way. Not just is a reluctant team more difficult to work with, imposing agile methods on reluctant people is fundamentally at odds with the whole notion of agile development.

2. It's valuable to also have customers (those who need the software) who want to work in this kind of collaborative way. If customers don't collaborate, then you won't see the full advantages of an adaptive process. Having said that we've found on several occasions that we've worked with customers who didn't want to collaborate, but changed their mind over the first few months as they begun to understand the agile approach.

3. Some people advise picking a project with little business impact to start with, that way if anything goes wrong then there's less damage. However an unimportant project often makes a poor test since nobody cares much about the outcome. I prefer to advise people to take a project that's a little bit more critical than you are comfortable with.

4. Perhaps the most important thing you can do is find someone more experienced in agile methods to help you learn. Whenever anyone does anything new they inevitably make mistakes. Find someone who has already made lots of mistakes so you can avoid making those yourself. Again this is something true for any new technology or technique, a good mentor is worth her weight in gold.

So where should you not use an agile method? I think it primarily comes down the people. If the people involved aren't interested in the kind of intense collaboration that agile working requires, then it's going to be a big struggle to get them to work with it. In particular I think that this means you should never try to impose agile working on a team that doesn't want to try it.