Herbjorn Wilhelmsen is an Architect and Senior Consultant at Objectware in Stockholm, Sweden. His main focus areas include service-oriented architecture, Web services and business architecture. Herbjörn has many years of industry experience working as a developer, development manager, architect and teacher in several fields of operations, such as telecommunications, marketing, payment industry, health care and public services. He is active as an author in the Prentice Hall Service-Oriented Computing Series from Thomas Erl and has contributed design patterns to SOAPatterns.org. He leads the Business-to-IT group in the Swedish chapter of the International Association of Software Architects, which performs a comparative study of a number of business architecture methodologies. Herbjörn holds a Bachelor of Science from Stockholm University.
Introduction
Services are useful, but they come with a price tag. The cost of developing a
service is higher than the cost of developing a traditional
(non-service-oriented) application, primarily due to the extra work and
infrastructure required. Another common concern when creating and consuming
services is the possibility of a performance hit. Together these issues hint
that even if you've decided to wholeheartedly adopt SOA, you may not want or
need to move all your functionality into services. This is where the
application Service Encapsulation becomes a focal point as we need specific
criteria to determine what should and should not be encapsulated into
services.
To make this determination, we will take a look at three different aspects:
-- acceptable reasons for ... (more)
Enterprise-wide harmonization is a desirable and ideal target state that
fully supports pretty much everything SOA and service-orientation stand for.
For those that have achieved such a state, bless your standardized hearts.
You have accomplished something that has eluded many others. However, not
attaining this state does not mean you cannot successfully adopt SOA.
In some circles it has... (more)
Like data normalization, the Service Normalization pattern is intent on
reducing redundancy and waste in order to avoid the governance burden
associated with having to maintain and synchronize similar or duplicate
bodies of service logic."
You can see it introduces the Pattern on our publisher page.
When designing data architectures, you can easily end up with different
databases or even... (more)
One of the fundamental goals when designing service-oriented solutions is to
attain a reduced degree of coupling between services, thereby increasing the
freedom and flexibility with which services can be individually evolved.
Achieving the right level of coupling "looseness" is most often considered a
design issue that revolves around the service contract and the consumer
programs that ... (more)
Should a service only be considered a service if it's reusable? The answer to
this question, as asserted by this pattern, is a firm "no." While agnostic
services (services providing multi-purpose logic with reuse potential, as per
the Agnostic Context pattern), receive the most attention during service
modeling and design phases, it can often be short-sighted to focus only on
agnostic se... (more)
Herbjorn Wilhelmsen is an Architect and Senior Consultant at Objectware in Stockholm, Sweden. His main focus areas include service-oriented architecture, Web services and business architecture. Herbjörn has many years of industry experience working as a developer, development manager, architect and teacher in several fields of operations, such as telecommunications, marketing, payment industry, health care and public services. He is active as an author in the Prentice Hall Service-Oriented Computing Series from Thomas Erl and has contributed design patterns to SOAPatterns.org. He leads the Business-to-IT group in the Swedish chapter of the International Association of Software Architects, which performs a comparative study of a number of business architecture methodologies. Herbjörn holds a Bachelor of Science from Stockholm University.
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