This based on my product development experience well as cloud research
Following are not in order though. You can use this as checklist.
1. If you are start-up and you have to implement some idea, but don’t have infrastructure.
2. If you have enough funding to try on cloud
3. If you have clear strategy and direction.
4. You have buy-in from your management and teams.
5. If you know what you want to do and you know you can get closer solution with particular vendor For example database, infrastructure, software as service.
6. When you don’t know what is your volume of infra you need.
7. When you have clear step-by-step methodology or model is ready.
8. You also have buy-in from your development team (in terms of software tools and process).
9. When you have customer buy-in.
10. When you know how much revenue savings and cost benefit
Please feedback. Many thanks for your time.