I see a lot of cloud computing projects fail in that they do not bring the promised ROI. In my book, if a project cannot live up to the projected ROI, it has failed.
There are three common cloud mistakes that lead to such ROI failure, each of which you can easily avoid.
Mistake 1: You miss the security boat
I know I sound like a broken record, but security is systemic to everything cloud. Cloud designers are architects, and they need to make sure security is considered at every point, including requirements, design, migration, testing, and operations.
Many companies consider security something that comes into play only during operations -- that's dangerous thinking. Why? Because security needs to be layered into the applications and the platform, and it can never be added as the last step. Identity and access management (IAM) is the most popular approach and technology, and it definitely requires some planning and understanding at each step.
Mistake 2: You map the target cloud platform improperly
You have to understand the target clouds well enough to make the right decisions around what and where to place your data and applications -- as well as how to use those services.
Moreover, you need to understand how these services be tracked, launched, and operated. It takes some research and planning to really nail this mapping, more than most enterprises grasp.
Mistake 3: You don't analyze the cost of operations
Guess what? You can actually spend more money running your workloads in the public cloud than in your own data center. Why? Because you don't have a clue as to what running specific workloads in the public cloud will cost you during operations.
What's needed are cost-monitoring and analytics systems to understand what you'll spend and when you'll spend it during operations. These tools are part of an overall governance strategy and systems you also need to have. (Many businesses don't bother.) You also need to keep tabs on the operational costs in the cloud after you deploy, because they might go up and change your ROI.