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Service-Oriented Discovery and Analysis Patterns 19
to a service. From a technical perspective, content download capability or audit trail functionality
can be assigned to utility services that fall under the technical category.
Second, services can be categorized by their origin, or the sources that a service stems from.
For example, a service may originate from a concept found in an organizational software portfolio
or even spotted in a production environment.
Third, from a structural perspective, a service can be classified by its internal formation type
or external distribution method.
These categorization approaches call for the institution of patterns that can help practitioners
classify a service by various aspects that define its identity. As discussed, these may be structural
considerations, contextual affiliations, and even origins. To learn more about these provided ser-
vice categorization patterns, refer to Chapters 11 through 13. The practitioner should leverage these
methods of classification to establish an organizational taxonomy that promotes service reuse, con-
solidation, reduction of expenditure, and nimbleness.
CONTEXTUAL ANALYSIS AND MODELING PATTERNS. Discussed in detail in Chapters 14 through
17, the contextual analysis and modeling patterns embody guiding principles for modeling services
to offer solutions based on their semantic affiliation. The term “semantic” describes a service’s asso-
ciation with a business or technical specialty, a field of expertise that can alleviate an organizational
concern. Accounting, home insurance, and trading are examples of specialties that can drive the
contextual modeling process. Therefore, the contextual modeling approach enables the manipula-
tion of a service’s functionality scope and the magnitude of its offerings in a hosting computing
environment. This approach typically affects the extent of a service’s capabilities and ultimately
affects the dimension of its consumers’ base.
To attain these goals, the contextual analysis process offers patterns to meet four different
objectives for a project:
1. Contextual generalization patterns. A group of patterns that increase the abstraction level
of a service to widen the boundary of its capabilities
2. Contextual specification patterns. Patterns employed to reduce service functionality and
abstraction level
3. Contextual expansion patterns. An assortment of contextual patterns that enable the ex-
pansion of a distributed service environment
4. Contextual contraction patterns. A collection of patterns that assists with the contraction
of a distributed service landscape and reduction of architecture scope
STRUCTURAL ANALYSIS AND MODELING PATTERNS. In contrast to the contextual analysis and
modeling patterns, which merely focus on semantic affiliations and manipulation of service func-
tionality and capabilities, the structural patterns are devised to shape internal and external service
formations to provide a superior solution. The term “structure” clearly pertains to two different
aspects of service design: internal and external. The former corresponds to an internal service con-
struct. This includes aggregation of service components, granularity level of a service, and even
establishment of contracts between a service’s constituents with their corresponding external con-
sumers. The patterns that help shape service external structures, however, address different concerns:
service distribution, service mediation, service federation, service integration, interoperability, and
more. Consider the four different structural analysis and modeling patterns that are discussed in
detail in Chapters 18 through 22:
1. Structural generalization patterns. Patterns that help widen a service’s internal structure
and as a result increase the boundary of its capabilities
2. Structural specification patterns. A group of patterns that trim down a service internal
formation to reduce the overall scope of its operations