MIN Faculty
Department of Informatics
Theoretical Foundations of Computer Science

Bibliography

Prototypische Realisierung einer Integration von Agenten und Workflows

Thomas Wagner.
Prototypische Realisierung einer Integration von Agenten und Workflows.
Diplomarbeit, Universität Hamburg, Department Informatik, Vogt-Kölln Str. 30, D-22527 Hamburg, 2009.

Abstract: Agent technology can be used to specify the structure of a software system by defining a set of entities. These entities, called agents, provide the entire functionality of the system. They possess certain characteristics, like autonomy and encapsulation, which facilitate their use in distributed software systems.
Workflow technology, on the other hand, can be used to describe the behavior of a set of interacting entities within a system. These entities, called resources, execute tasks and exchange data according to a predefined process. Systems, designed with workflow technology, are used to support the business processes of a company.
It is possible to design large and complex systems with both technologies. They both contain a strong focus on different aspects of a system. While agent technology focuses on the structure and distribution of the different entities, the workflow technology focuses on the behavior and dataflow between them. The integration of these two, almost opposite, views is the main objective of this contribution. Workflow technology will be used to enhance agent technology and vice versa. The integration is based on the theoretical, overall architecture proposed in [Reese09]. This architecture consists of five tiers. Beginning with regular agent or workflow systems, each tier introduces new concepts, which integrate both technologies more and more.
This contribution describes a number of prototypical implementations, which can be classified within the overall architecture. The prototypes are based on the Mulan and Capa agent architectures and use workflow nets to model processes. The first system, which is described, is an agent-based Workflow Management System (AgWFMS). It can be classified as a system of the second tier of the overall architecture. This AgWFMS provides workflow-functionality by solely relying on agents and is used as the technological basis for the other two prototypes. These other prototypes are the structure-agent-workflow (S-AgWf) and the protocol dispatcher (ProDi) system. The functionality needed by both systems is provided by a combination of the AgWFMS and the Mulan and Capa agent architectures. This combination, though not a separate prototype, can be classified as a system of the third tier of the overall architecture. These S-AgWf and ProDi prototypes represent the two variations of the fourth tier of the overall architecture. For application development the S-AgWf system offers the capabilities of a workflow management system. Internally though, the system strongly relies on agent technology. Through this use of agent technology the system benefits in certain areas, for example distributed workflow execution. The ProDi system, on the other hand, offers the capabilities of an agent management system, which can be used to design and implement agent applications. Internally, it uses workflow technology to model and support the interactions between the different agents of the system. Because of this, the interactions are more flexible and the system becomes more fault-tolerant, compared to the regular execution of interactions.
All prototypes are described using the Paose-development approach and are discussed in detail. Practical examples of their use are given.


BibTeX entry



@MASTERSTHESIS{Wagner09a,
  author = {Wagner, Thomas},
  title = {{Prototypische Realisierung einer Integration von Agenten und Workflows}},
  school = FBIUniHHab2006,
  year = 2009,
  type = diplomarbeit,
  address = FBIUniAdresse,
  abstract = {Agent technology can be used to specify the structure of a software
	system by defining a set of entities. These entities, called agents,
	provide the entire functionality of the system. They possess certain
	characteristics, like autonomy and encapsulation, which facilitate
	their use in distributed software systems.

	Workflow technology, on the other hand, can be used to describe the
	behavior of a set of interacting entities within a system. These
	entities, called resources, execute tasks and exchange data according
	to a predefined process. Systems, designed with workflow technology,
	are used to support the business processes of a company.

	It is possible to design large and complex systems with both technologies.
	They both contain a strong focus on different aspects of a system.
	While agent technology focuses on the structure and distribution
	of the different entities, the workflow technology focuses on the
	behavior and dataflow between them. The integration of these two,
	almost opposite, views is the main objective of this contribution.
	Workflow technology will be used to enhance agent technology and
	vice versa. The integration is based on the theoretical, overall
	architecture proposed in [Reese09]. This architecture consists of
	five tiers. Beginning with regular agent or workflow systems, each
	tier introduces new concepts, which integrate both technologies more
	and more.

	This contribution describes a number of prototypical implementations,
	which can be classified within the overall architecture. The prototypes
	are based on the Mulan and Capa agent architectures and use workflow
	nets to model processes. The first system, which is described, is
	an agent-based Workflow Management System (AgWFMS). It can be classified
	as a system of the second tier of the overall architecture. This
	AgWFMS provides workflow-functionality by solely relying on agents
	and is used as the technological basis for the other two prototypes.
	These other prototypes are the structure-agent-workflow (S-AgWf)
	and the protocol dispatcher (ProDi) system. The functionality needed
	by both systems is provided by a combination of the AgWFMS and the
	Mulan and Capa agent architectures. This combination, though not
	a separate prototype, can be classified as a system of the third
	tier of the overall architecture. These S-AgWf and ProDi prototypes
	represent the two variations of the fourth tier of the overall architecture.
	For application development the S-AgWf system offers the capabilities
	of a workflow management system. Internally though, the system strongly
	relies on agent technology. Through this use of agent technology
	the system benefits in certain areas, for example distributed workflow
	execution. The ProDi system, on the other hand, offers the capabilities
	of an agent management system, which can be used to design and implement
	agent applications. Internally, it uses workflow technology to model
	and support the interactions between the different agents of the
	system. Because of this, the interactions are more flexible and the
	system becomes more fault-tolerant, compared to the regular execution
	of interactions.

	All prototypes are described using the Paose-development approach
	and are discussed in detail. Practical examples of their use are
	given.}
}


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