Mark F. Hornick

An overview of workflow management: from process modeling to workflow automation infrastructure

Todays business enterprises must deal with global competition, reduce the cost of doing business, and rapidly develop new services and products. To address these requirements enterprises must constantly reconsider and optimize the way they do business and change their information systems and applications to support evolving business processes. Workflow technology facilitates these by providing methodologies and software to support (i) business process modeling to capture business processes as workflow specifications, (ii) business process reengineering to optimize specified processes, and (iii) workflow automation to generate workflow implementations from workflow specifications. This paper provides a high-level overview of the current workflow management methodologies and software products. In addition, we discuss the infrastructure technologies that can address the limitations of current commercial workflow technology and extend the scope and mission of workflow management systems to support increased workflow automation in complex real-world environments involving heterogeneous, autonomous, and distributed information systems. In particular, we discuss how distributed object management and customized transaction management can support further advances in the commercial state of the art in this area.

DISTRIBUTED OBJECT MANAGEMENT

Future information processing environments will consist of a vast network of heterogeneous, autonomous, and distributed computing resources, including computers (from mainframe to personal), information-intensive applications, and data (files and databases). A key challenge in this environment is providing capabilities for combining this varied collection of resources into an integrated distributed system, allowing resources to be flexibly combined, and their activities coordinated, to address challenging new information processing requirements. In this paper, we describe the concept of distributed object management, and identify its role in the development of these open, interoperable systems. We identify the key aspects of system architectures supporting distributed object management, and describe specific elements of a distributed object management system being developed at GTE Laboratories.

Customizing transaction models and mechanisms in a programmable environment supporting reliable workflow automation

A Transaction Specification and Management Environment (TSME) is a programmable system that supports implementation-independent specification of application-specific extended transaction models (ETMs) and configuration of transaction management mechanisms (TMMs) to enforce specified ETMs. The TSME can ensure correctness and reliability while allowing the functionality required by workflows and other advanced applications that require access to multiple heterogeneous, autonomous, and/or distributed (HAD) systems. To support ETM specification, the TSME provides a transaction specification language that describes dependencies between transactions. Unlike other ETM specification languages, TSMEs dependency descriptors use a common set of primitives, and are enforceable, i.e., can be evaluated at any time during transaction execution to determine whether operations issued violate ETM specifications. To determine whether an ETM can be enforced in a specific HAD system environment, the TSME supports specification of the transactional capabilities of HAD systems, and comparison of these with ETM specifications to determine mismatches. To enforce ETMs that are more restrictive than those supported by the union of the transactional capabilities of HAD systems, the TSME provides a collection of transactional services. These services are programmable and configurable, i.e., they accept instructions that change their behavior as required by an ETM and can be combined in specific ways to create a run-time TMM capable of enforcing the ETM. We discuss the TSME in the context of a distributed object management system. We give ETM specification examples and describe corresponding TMM configurations for a telecommunications application.

Specification and management of extended transactions in a programmable transaction environment

A Transaction Specification and Management Environment (TSME) is a transaction processing system toolkit that supports the definition and construction of application-specific extended transaction models (ETMs). The TSME provides a transaction specification language that allows a transaction model designer to create implementation-independent specifications of extended transactions. In addition, the TSME provides a programmable transaction management mechanism that assembles and configures a run-time environment to support specified ETMs. The authors discuss the TSME in the context of a distributed object management system (DOMS), and describe specifications of extended transactions and corresponding configurations of transaction management mechanisms.<<ETX>>

A FRAMEWORK FOR ENFORCEABLE SPECIFICATION OF EXTENDED TRANSACTION MODELS AND TRANSACTIONAL WORKFLOWS

A variety of extensions to the traditional (ACID) transaction model have resulted in a plethora of extended transaction models (ETMs). Many of these ETMs are application-specific, i.e. they are designed to provide correctness guarantees adequate for a particular application, but not others. Similarly, an application-specific ETM may impose restrictions that are unacceptable in one application, yet required in another. To define new ETMs, to determine whether an ETM is appropriate for an application, and to integrate ETMs to produce new ETMs, we need a framework for ETM specification and reasoning. In this paper, we describe such a framework. Our framework supports implementation-independent specification of ETMs described in terms of dependencies between transactions. Dependencies are specified using dependency descriptors. Unlike other transaction specification frameworks, dependency descriptors use a common set of primitives, and are enforceable, i.e. can be evaluated at any time during transaction execution to determine whether issued operations violate ETM specifications. We discuss specifications of (i) structure dependencies between transaction states, and (ii) correctness dependencies for serializability, various cooperative and temporal correctness criteria, and recoverability. We give ETM specification examples for a telecommunications application illustrating the definition of a new application-specific ETM using our framework.

An environment for the specification and management of extended transactions in DOMS

A transaction specification and management environment (TSME) is a toolkit that supports the definition and construction of specific extended transaction models corresponding to application requirements. The TSME provides a transaction specification language that allows a transaction designer to create implementation-independent specifications of extended transactions. In addition, the TSME provides a programmable transaction management mechanism (TMM) that assemblies and configures a run-time environment to support specified extended transaction models. The authors discuss the TSME in the context of a distributed object management system (DOMS).<<ETX>>