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On the other hand there are industrial tools supporting a (graphical) com-
ponent-based programming style, like e.g., the visual modelling in Rational's
Suite [18], supporting Microsoft's Visual Studio, or the Rapid Application De-
velopment now included in Oracle's Designer [16]. But these tools do not provide
any sophisticated means for consistency control.
In this paper we present our experience with
,atoolfor
formal
methods-based, application-specic
software design, which is designed for directly
supporting the `programming-free' programming style of applications. To our
knowledge,
M
eta
Frame
is unique in using formal methods to explicitly address
the issue of separation of concerns between programmers, application experts,
and end users.
The remainder of this section sketches the
M
eta
Frame
environment, before
giving some background of the application domain, the development of Intelligent
Network Services, which we will use to explain our approach in more detail.
M
eta
Frame
1.1
The
M
eta
Frame
Environment
We provide here an overview of
in the light of the announced
`programming-free programming' paradigm of application development. This im-
poses to stress the following characteristics:
M
eta
Frame
Behaviour-Oriented Development:
Application development consists in the be-
haviour-oriented combination of Building Blocks (BBs)
1
on a
coarse
granular
level. BBs are here identied on a functional basis, understandable to appli-
cation experts, and usually encompass a number of `classical' programming
units (be they procedures, classes, modules, or functions). They are organized
in application-specic collections. In contrast to (other) component-based ap-
proaches, e.g., for object-oriented program development,
focusses
on the dynamic behaviour: (complex) functionalities are graphically stuck to-
gether to yield flow graph-like structures embodying the application behaviour
in terms of control. This graph structure is independent of the paradigm of
the underlying programming language, which, as in the application described
later, may, e.g., well be an object-oriented language: here the coarse granular
BBs are themselves implemented using all the object oriented features, and only
their combination is organized operationally. In particular, we view this flow-
graph structure as a control-oriented coordination layer on top of data-oriented
communication mechanisms enforced e.g. via RMI, CORBA or (D)COM. Ac-
cordingly, the purely graphical combination of BBs' behaviours happens at a
more abstract level, and can be implemented in any of these technologies.
M
eta
Frame
1
BBs are software components with a particularly simple interface. This kind of in-
terface enables one to view BBs semantically just as input/output transformations.
Additional interaction structure can also be modelled, but is not subject to the
formal synthesis and verication methods (see Sections 3.3 and 3.6).
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