Methodologies for Design of Service-Based Systems - Intentional Perspectives on Information Systems Engineering - page 310

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Alt.
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a

Alt.
2

3

1

b

1

c

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Executor level

Fig. 6 From intentional maps to enacted services [ 10]

The intentional services can be mapped to different compositions of services and
offer the choice of variants at run time.
As shown in Fig. 6, such variants can be represented in multiple levels, depending
on the available alternatives derived from the maps. During execution, a con-
trol agent controls the selection and execution of a given composition, which
corresponds to a path in a map.
In this way, alternatives available for dynamic service selection at run time
are specified, and these alternatives correspond to business goals expressed in the
requirements phase.

5 Conclusion

In the present chapter, we discussed some approaches which have been proposed as
methodological frameworks for service design.
We illustrated first how traditional software design life-cycles are evolving for
service-based applications and how one characteristic aspect of service design is to
take into consideration the flexibility of adaptation mechanisms provided by service
orientation.
We also discussed how most approaches adopt for service design, in the ini-
tial phases of requirements engineering, the same approaches which are applied in
traditional software development.
The approach proposed in [ 10] represents an interesting original research
approach which has the goal of preserving the flexibility aspects of services while
linking their construction directly to specified requirements, supporting the service
construction with a rigorous and formal approach.