Page 120 - Cloud Essentials

The ITIL life cycle consists of four common IT service management

phases we will correlate to cloud computing:

Service Strategy
Service Design
Service Operation

Service Transition

Service Strategy Managing service levels is a critical part of adopting
cloud computing. Because capacity becomes elastic, there is no longer a

hard limit on its usage. This is good for performance but potentially bad for
cost. As a result, service level agreements with providers take an entirely
new shape. With this in mind, the following are some important questions to
answer when reviewing service level agreements:

How elastic is the capacity?
Can the provider deny you a capacity increase?

Does the provider have any guarantees on the upper limit?

How well can you cap or limit usage (ensuring costs cannot exceed a
specified dollar amount)?
How is capacity scaled back when no longer needed?

Remember at all times that with cloud computing the cost base will be
much more variable. Traditional chargeback models may change because of

the speed at which cloud computing services can be provisioned and
deprovisioned. The more you automate the processes around dynamic
resource allocation and sharing, the more productive and efficient they will
become.

Service Design Cloud adoption introduces new IT services that can be
rapidly provisioned using self-service web portals. Existing IT services in

the organization can sometimes be integrated with cloud offerings, thus
improving an existing service. For example, your company might host
employee email accounts on local mail servers, but before mail arrives on
premises, virus scanning and spam filtering are done through a cloud
provider service. Cloud services must be monitored to ensure performance
is optimal, as shown in Figure 5-1.

FIGURE 5-1 Monitoring applications and infrastructure to ensure a

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