In IT service delivery and support, the cloud paradigm has introduced the
problem of resource over-provisioning through rapid automation (or
orchestration) of manual IT operations. Due to the elastic nature of cloud
computing, this shortcoming ends up significantly reducing the real benefit,
viz., the cost-effectiveness of cloud adoption for Cloud Service Consumers
(CSC). Similarly, detecting and eliminating such over-provisioning of cloud
resources without affecting the quality of service (QoS) is extremely
difficult for Cloud Service Providers (CSPs) since they have visibility only
into the state of the IT services (cloud resources) but none into the actual
performance of business services. In this paper, we propose T-BICA
(Tier-centric Business Impact and Cost Analysis), a tier-centric optimal
resource allocation algorithm, to address the problem of rapid provisioning of
IT resources in modern enterprise cloud environments, through extensive data
gathering and performance analyses of business services in a simulated
environment emulating a mature cloud service provider. We have derived
improved analytics to address the issues and to accelerate real cloud adoption
for large enterprises within the context of meeting (or exceeding) business
service level objectives (SLOs) and minimizing the cloud subscription cost
(OpEx) for the business. While investigating the problem, we consider the
time and the cost of delivering business service in medium- to large-size
enterprise environments, quantifying the negative impact of IT resource
over-provisioning (due to highly mature IT services centric orchestration
capabilities) on the business, and indicate how the suggested cloud analytics
could assist in reducing total cost of ownership (TCO) of the business
service. From our analysis of the test data, we have observed that our
suggested approach and analytic reduces the cost of delivering business
services by 65.19%, and improves the performance (total time to deliver) by
74.18% when compared to the existing modern cloud management and resource
provisioning approach. Using T-BICA also dramatically reduces upfront costs
(CapEx) for CSPs (from the capacity procurement and management points of view)
through efficient on-demand resource de-provisioning, without affecting
business SLOs and IT service level agreements (SLAs). The improved dynamic
allocation of resources also makes for better efficiency of utilization, which
in turn has desirable consequences for sustainability, and makes this an
approach for ``Green'' IT.