Information Technology Reference
In-Depth Information
8.5 Common Capabilities for managing Service Level Agreements
Quality of Service (QoS) is in essence about a set of quality metrics that have to
be achieved during the service provision. These metrics must be measurable and
constitute (part of) a description of what a service can offer. The QoS of IT serv-
ices is often expressed in terms of capacity, latency, bandwidth, number of served
requests, number of incidences, etc. The QoS of services offered to the customer is
sometimes expressed as a package (for example bronze, silver, gold) and in relation
to key performance indicators (KPI). In this case, a match between the elements of
the scale and measurable metrics relative to the service is provided.
A Service Level Agreement (SLA) defines the QoS of the services offered.
Typically SLA is a formal written agreement made between two parties: the service
provider and the service user, defining the delivery of the service itself. The docu-
ment can be quite complex, and sometimes underpins a formal contract. The
contents will vary according to the nature of the service itself, but usually includes a
number of core elements, or clauses. These define a specific level of service, support
options, incentive awards for service levels exceeded and/or penalty provisions for
services not provided, etc. Some organizations, attempting to avoid negative conno-
tations, prefer to use the terms SLE (service-level expectation) or SLG (service-
level goal) for the definition of the QoS of the services they offer.
Fig. 8.6:
Summary of an impact assessment of SLA use for IT services (Biddick 2008)
Functional service-level agreements attracted high interest from telecommunica-
tion service providers in the late 1990s. More recently enterprise, government, and
academic environments have been moving towards SLA-driven services as more
of the commonly used services are now being delivered online. However, as was
the case with the telecommunications industry in the '90s, the right elements to
generate and manage a successful SLA are rarely in place. Many organizations that
depend on IT lack the governance structures, service catalogues, defined processes,
