|The issues of refinement of the information system activity (workflow)
specifications by the pre-existing heterogeneous information resource behavior
patterns are discussed. The proposed approach is considered to be a part
of the semantic interoperation reasoning framework. The twodimensionally
uniform multiactivity specification is assumed. The technique is
developed and used in frame of the SYNTHESIS project.
A chunk-based model is proposed to abstract the structural aspects of
the multiactivity specifications. Chunk is a code of a piece of an activity
between "significant events" (such as termination of the current action,
spawning of another (child or the same level) action or chunk, aborting
of the current or a child action). On such call/return events (controlled
by chunk junction) specific control depending on the multiactivity model
may be applied. So, component activity is abstracted as a sequence of chunks
with significant events in between. Chunkpack is a sequence of chunks separated
by call/return of the components (actions and chunkpacks).
Chunk junctions ( Generic Intercomponent Control Modules (GICM)) accumulate
facilities for proper interpretation of significant events preserving interactivity
dependencies defined for a specific multiactivity model. Using these simple
abstractions, a multilayered structure can be specified where on each layer
several chunkpacks may be located. In a nested case each two adjacent layers
are parent layer and its direct child layer so that on the top level only
one chunkpack is located.
A chunkpack is conveniently represented by hierarchical scripts where
the chunk junctions reflecting the specific features of a particular multiactivity
(multitransaction) model are defined by the child scripts generated from
one generic script once designed for each specific multiactivity model.
The generation consists in providing of parameters for the generic script
to communicate with concrete chunks and to call a child chunkpack and its
compensation actions (if such child is required).
Chunk model provides for decomposition of the multiactivity concretization
problem into subproblems for which the general function concretization
methodology could become applicable. Such decomposition is based on the
principles of isolation of pure functional behavior, structural localization
of concurrency control in GICM, concurrency specification abstraction for
particular multiactivity models.
Application of these principles leads to the creation of general framework
of the multiactivity concretization by the pre-existing multiactivity behaviors.