Advanced Architectures for Transactional Workflows or Advanced Transactions in Workflow Architectures

In this short paper, we outline the workflow management systems research in the Information Systems division at the University of Twente. We discuss the two main themes in this research: architecture design and advanced transaction management. Attention is paid to the coverage of these themes in the context of the completed Mercurius and WIDE projects and in the new CrossFlow project. In the latter project, contracts are introduced as a new theme to support electronic commerce aspects in workflow management

On deep e-contracting

The use of electronic contracts is emerging as a way to improve the effi-ciency of contracting processes. Electronic contracts are, however, often used as a direct replacement for traditional paper contracts - which we call shallow e-contracting. Consequently, business processes in general and contracting processes in particular do not change much through the use of electronic contracts. New business scenarios caused by e-business developments, however, do require new contracting paradigms in which the use of electronic contracts becomes an essential element to obtain a radical paradigm shift in contractual business relations - which we call deep e-contracting. In this position paper, we explore these new para-digms. We link the paradigms to exchanged values described in e-contracts to obtain a mapping from business requirements. We next map the paradigms to contracting activities. Finally, we map the activities to information technology required for their automated support. Based on the paradigms and mappings, this paper provides a concise framework for the exploration of deep e-contracting.\ud

Protocols for Integrity Constraint Checking in Federated Databases

A federated database is comprised of multiple interconnected database systems that primarily operate independently but cooperate to a certain extent. Global integrity constraints can be very useful in federated databases, but the lack of global queries, global transaction mechanisms, and global concurrency control renders traditional constraint management techniques inapplicable. This paper presents a threefold contribution to integrity constraint checking in federated databases: (1) The problem of constraint checking in a federated database environment is clearly formulated. (2) A family of protocols for constraint checking is presented. (3) The differences across protocols in the family are analyzed with respect to system requirements, properties guaranteed by the protocols, and processing and communication costs. Thus, our work yields a suite of options from which a protocol can be chosen to suit the system capabilities and integrity requirements of a particular federated database environment

A Three-Level Process Framework for Contract-Based Dynamic Service Outsourcing

Service outsourcing is the business paradigm, in which an organization has part of its business process performed by a service provider. In dynamic markets, service providers are selected on the fly during process enactment. The cooperation between the parties is\ud specified in a dynamically made electronic contract. This contract includes a process specification that is tailored towards service matchmaking and crossorganizational process enactment and hence has to conform to specific market and specification standards. Process enactment, however, relies on intraorganizational process specifications that have to comply with the infrastructure available in an organization. In this position paper, we present a three-level process specification framework for dynamic contract-based\ud service outsourcing. This framework relates the two process specification levels through a third, conceptual level. This approached is inspired by the well-known ANSI-SPARC model for data management. We show how the framework can be placed in the context of infrastructures for cross-organizational process support

Integrity Constraint Checking in Federated Databases

A federated database is comprised of multiple interconnected databases that cooperate in an autonomous fashion. Global integrity constraints are very useful in federated databases, but the lack of global queries, global transaction mechanisms, and global concurrency control renders traditional constraint management techniques inapplicable. The paper presents a threefold contribution to integrity constraint checking in federated databases: (1) the problem of constraint checking in a federated database environment is clearly formulated; (2) a family of cooperative protocols for constraint checking is presented; (3) the differences across protocols in the family are analyzed with respect to system requirements, properties guaranteed, and costs involved. Thus, we provide a suite of options with protocols for various environments with specific system capabilities and integrity requirement

Extending a multi-set relational algebra to a parallel environment

Parallel database systems will very probably be the future for high-performance data-intensive applications. In the past decade, many parallel database systems have been developed, together with many languages and approaches to specify operations in these systems. A common background is still missing, however. This paper proposes an extended relational algebra for this purpose, based on the well-known standard relational algebra. The extended algebra provides both complete database manipulation language features, and data distribution and process allocation primitives to describe parallelism. It is defined in terms of multi-sets of tuples to allow handling of duplicates and to obtain a close connection to the world of high-performance data processing. Due to its algebraic nature, the language is well suited for optimization and parallelization through expression rewriting. The proposed language can be used as a database manipulation language on its own, as has been done in the PRISMA parallel database project, or as a formal basis for other languages, like SQL

A Conceptual Framework for B2B Electronic Contracting

Electronic contracting aims at improving existing business relationship paradigms and at enabling new forms of contractual relationships. To successfully realize these objectives, an integral understanding of the contracting field must be established. In this paper, we propose a conceptual framework for business-to-business contracting support. The framework provides a complete view over the contracting field. It allows positioning research efforts in the domain, analysing them, placing their goals into perspective, and overseeing future research topics and issues. It is the basis for drawing conclusions about basic requirements to contracting systems

Component Based System Framework for Dynamic B2B Interaction

Business-to-business (B2B) collaboration is becoming a pivotal way to bring today's enterprises to success in the dynamically changing, e-business environment. Though many business-to-business protocols are developed to support B2B interaction, none are generally accepted. A B2B system should support different B2B protocols dynamically to enable interaction between diverse enterprises. This paper proposes a framework for dynamic B2B interaction. A B2B transaction is divided into the interaction part and business implementation part to support flexible interaction. A component based system framework is proposed,to support the B2B transaction execution. To support. dynamic B2B services, dynamic component composition is required. Service and component notions are combined into a composable service component. The composition architecture is also presented

Two Case Studies of Subsystem Design for General-Purpose CSCW Software Architectures

This paper discusses subsystem design guidelines for the software architecture of general-purpose computer supported cooperative work systems, i.e., systems that are designed to be applicable in various application areas requiring explicit collaboration support. In our opinion, guidelines for subsystem level design are rarely given most guidelines currently given apply to the programming language level. We extract guidelines from a case study of the redesign and extension of an advanced commercial workflow management system and place them into the context of existing software engineering research. The guidelines are then validated against the design decisions made in the construction of a widely used web-based groupware system. Our approach is based on the well-known distinction between essential (logical) and physical architectures. We show how essential architecture design can be based on a direct mapping of abstract functional concepts as found in general-purpose systems to modules in the essential architecture. The essential architecture is next mapped to a physical architecture by applying software clustering and replication to achieve the required distribution and performance characteristics