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process. The more processes that an enterprise decomposes in
this way, the more commonality across these subprocesses can be
achieved. In this way, an enterprise has the chance of building an
appropriate set of reusable business services.
This layer relies on the orchestration interface of a collection of
business-aligned services to realize reconfigurable end-to-end
business processes. Individual services or collections of services
that exhibit various levels of granularity are combined and orches-
trated to produce new composite services that not only introduce
new levels of reuse but also allow the reconfiguration of business
processes.
The interfaces get exported as service descriptions in this layer
using a service description language, such as WSDL. The service
description can be implemented by a number of service providers,
each offering various choices of qualities of service based on techni-
cal requirements in the areas of availability, performance, scalability,
a nd s e c u r it y.
During the exercise of defining business services, it is also
important to take existing utility logic, ingrained in code, and
expose it as services, which themselves become candidate ser-
vices that specify not the overall business process but rather the
mechanism for implementing the process. This exercise should thus
yield two categories of services: business functionality services that are
reusable across multiple processes and a collection of fine-grained util-
ity (or commodity ) services , which provide value to and are shared by
business services across the organization. Examples of utility services
include services implementing calculations, algorithms, and directory
management services.
4. Infrastructure services : Infrastructure services are subdivided into
technical utility services, access services, management and moni-
toring services, and interaction services; these are not specific to
a single line of business but are reusable across multiple lines of
business. They also include mechanisms that seamlessly inter-
link services that span enterprises. This can, for example, include
the policies, constraints, and specific industry messages and inter-
change standards (such as the need to conform to specific industry
message and interchange standards like EDIFACT, SWIFT, xCBL,
ebXML BPSS, or RosettaNet) that an enterprise, say within a par-
ticular vertical marketplace, must conform to in order to work with
other similar processes. Access services are dedicated to transforming
 
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