Cloud Computing and SOA Convergence in Your Enterprise: A Step ...

68 Chapter 4 Making the Business Case for Clouds
Upsizing On Demand
Core to the ability to preserve capital is the ability to upsize your IT infrastructure
on demand, or simply pay more money for additional computing
capacity. Many cloud computing providers call this being elastic, or having
the ability to grow or contract to accommodate the business. There are a few
terms to consider here:
Service tiers
Existing resources
Ability to scale
Service tiers are offered by some cloud computing providers: for example,
you can purchase some capacity for $1,000 a month, the next tier up is
$2,500, and the next one up is $5,000. Therefore, you must consider the cost
of service tiers compared to more granular billing methods.
You have to consider the contracts as well. While some are monthly,
some are yearly, and some are both. Thus, many of those contracts can drive
a commitment that may not be right for the enterprise. Make sure to read the
service agreement carefully before selecting a cloud computing provider, and
make sure you understand what will happen if you move from that provider,
increase processing, or decrease processing (discussed shortly). Do this before
selecting the provider and signing the agreement.
Existing resources refers to the fact that you may have some computing
capacity around in the data center that is already bought and paid for, and
thus using those resources should be considered. However, you also need to
consider the costs of development and maintenance, which are typically
where the real costs come in. The trick is to understand that your CIO will
probably ask about those resources during the cloud computing discussions,
and you need to have a well-thought-out answer. The answer could be that
moving to cloud computing is not cost justified, considering the existing investment
in hardware, software, and data center space.
Ability to scale is the ability for the cloud computing provider to actually
provide the capacity you require to support the additional computing resources
you will need. While most can scale up to your needs, there are some
that will not be able to handle the additional load no matter how much
money you pay them. You need to determine that up front.