Current enterprise apps can't be migrated conveniently
Risk: Legal, regulatory, and business
Difficulty of managing cloud applications
Lack of SLA
Lack of cost advantage for cloud computing
All good points, but here's some further analysis:The issues around the migration of applications are very important; indeed, most applications ported to cloud platforms will need a great deal of rework, testing and redeployment. Thus, as I've been saying, most cloud applications will be new applications.
However, this does not consider the fact that most firms won't just migrate enterprise applications to the cloud, but instead leverage cloud infrastructure components as a jumping off point, such as storage-as-a-service and database-as-a-service. This will minimize the impact of code migration, which is always painful.
The second point, around legal, regulatory and business risk, is really an issue you should consider with any system, cloud-bound or not. Thus, if information is not allowed on remote platforms, don't put it there. For some key systems this is an issue; but for most, it's not. System criticality is another concern, as Golden points out, but like other concerns, downtime is an issue no matter if it's cloud-based or not.
Management of cloud applications is very important, considering that you encompass systems that are outside of your control. As we continue down this cloud journey, we'll see new cloud offerings that improve upon management. There are a few players today, but their offerings are somewhat rudimentary.
As far as an SLA goes, many cloud providers will provide an SLA. However, all the SLAs won't save you from a bad provider. Sometimes I think SLAs give you a false sense security. Independent validation is a much better approach.
Finally, the lack of cost advantage is another key consideration. While cloud computing is sold as providing "significant cost savings," your actual savings is largely dependent upon the business and technical issues you currently deal with within your enterprise. You always need to create a realistic business case for the use of cloud computing, considering the cost of operations, the cost of migration, the cost of security, and other things that are typically an afterthought.
I'm glad there is some critical thinking around cloud computing. It's never a good idea to jump into something without careful thought and due diligence. This sort of examination will only make cloud computing better since it will make expectations realistic.While many advocate cloud computing, others are weighing the fit within the modern enterprise. Bernard Golden lists five key areas of concern for enterprises considering cloud computing: Current enterprise apps can't be migrated conveniently; Legal, regulatory and business risk; the difficulty of managing cloud applications; the lack of SLAs; and the lack of a cost advantage for cloud computing. All good points, but here's some further analysis...