Agent-based Approach to Workflow and Supply Chain Management YUNHE LIAO, HINNY P. KONG School of Electrical and Electronic Engineering Nanyang Technological University Block S1, Nanyang Avenue Singapore 639798 Abstract:- Enabled by the evolution in information technology, companies are constantly trying to re-engineer their business processes to be more productive and efficient to respond to the quickly changing environment. A number of workflow management systems (WFMSs) have been developed by various research groups and companies to meet these requirements. After decades of evolution, they are moving from centralized to distributed mode and have become more and more flexible. However, in executing processes of different enterprises, flexibility and distributed processing capability are still the main challenges. In this paper, we propose an agent-based WFMS (aWFMS), which is designed to be flexible, distributed, easily integratable, and capable of executing processes enterprise-wide. XML is chosen as our agent communication and process definition language. The proposed model is applied to Supply Chain Management (SCM) applications. Keywords: - Workflow, Workflow Management System, Agent, XML, Supply Chain Management 1. Introduction restricted functionality are the main reasons that preventing companies from investing in workflow. Workflow as a concept has been existed for Another interesting phenomenon is that despite the decades. The earliest known WFMS is Officetalk large number of technical users who need to developed by Ellis and Nutt [1] in the Xerox PARC. customize their own workflow solutions, most existing In the 1980s, some office automation and document WFMSs target only at non-technical users. Besides imaging workflow product have been developed [2]. workflow functionality they also provide high level Since the early 1990s, workflow has been the focus visual tools that support workflow configuration, but of intense activity in terms of products, standards and are close-ended system that are not extendable or research work [3]. There are various definitions been programmable [6]. The functionality gap between the proposed for Workflow and WFMS over the years. current WFMSs and requirements of inter-enterprise In 1993, some workflow vendors, Analysts and applications and technical users suggests the future Research Groups came to form the Workflow direction of research for workflow management. Management Coalition (WfMC) [4]. WfMC now is the major group that involves in workflow In this paper, we propose an aWFMS model based management standardization. on IBM’s Aglet Software Development Kit (SDK) (http://www.trl.ibm.com/aglets/). The proposed Despite the potential benefits that workflow aWFMS consists of various types of agents. We technology can bring to companies and the large define the abstract class for each type of agent. New number of WFMSs available in the market, Amit and agents can be built by developers and plugged into his colleges from Georgia [5] observed that current the aWFMS to support various applications. By using WFMSs were not quite successful. And they component agents to build an aWFMS, great concluded that lack of flexibility, real standard, and flexibility and integrability can be achieved. Workflow 1 process can be executed distributively over a few The new system is named Exotica/FMQM. In the aWFMSs that cooperate with each other using new system, execution of business process is agents. XML is chosen as our agent communication distributed. Each node of the process maintains the language. required persistent storage. The rest of this paper covers a review of some of the This information is used to recover from failures better known WFMSs (Sect. 2), IBM’s ASDK and occurred at this node. A messaging system called XML technologies (Sect. 3), our proposed WFMS MQSeries is used in Exotica/FMQM to support model (Sect. 4), and demonstration of this model in asynchronous communication between different SCM applications (Sect. 5), and opportunities for parties of the WFMS. further work (Sect. 6). · The Mentor-lite WFMS 2. Review of Existing WFMSs The Mentor project (Middle ware for Enterprise- wide Workflow Management) is a collaboration A good number of WFMSs were offered in the project of the University of Saarland and the Union market in the 1990s, such as I-Flow from the Fujitsu Bank of Switzerland. The early version of workflow Software Corporation [7], Emailflow for management system models workflow with state and Exchange/SMTP from Docman [8], EntireX from activity charts [14]. Initially it focused on deriving Software AG [9], Exitoca/FMQM from IBM [10], distributed workflows starting from formal FloWare from Plexus [11], JetForm Workflow from specifications. An algorithm that transforms a Jet Form [12], Livelink Workflow from the Open centralized state and activity chart into a provably Text Corporation [13], Mentor-lite from University of equivalent partitioned one and is suitable for Saarland [14], WIDE from the WIDE research group distributed execution was developed. As work went [15], Workflow Suite from the Ultimus Corporation on, the researches realized the limitations of the [16]. The number is estimated to be between 200-300 workflow architectures. in 1999 [5]. Herein, four of the WFMSs that have deeper impacts on workflow technology are Consequently they continue to work on Mentor-lite, a reviewed: Exitoca/FMQM, Mentor-lite, WIDE and second-generation Mentor system. Mentor-lite is a EntireX. lightweight WFMS. It separates the workflow kernel functionality from the additional functionality of · Exitoca/FMQM From IBM workflow systems, and it supports the incremental FlowMark is the initial workflow product from IBM integration of workflow technology within existing [9]. It is built based on the client/server architecture. business environments. System components like The server, in turn is a client of a centralized history management and worklist management are database, ObjectStore, where both runtime and extensions of the kernel. An invocation interface for buildtime workflow information is stored. At runtime, application programs is provided by a generic IDL information flows from the database to the server, interface on the engine side and specific wrappers on from the server to the runtime client, and vice versa. the application side. The centralization of database forces the clients to be connected to the server at all times to be able to The workflow engine kernel consists of three progress in their work, thus it is vulnerable to server components: (i) the workflow specifications failures and offers limited scalability due to the interpreter, (ii) the communication manager potential performance bottleneck caused by the (ComMgr), and (iii) the log manager (LogMgr), centralized server. To overcome these problems, which are closely integrated with the interpreter. IBM designed a distributed architecture for a WFMS They use state and activity charts for process with improved reliability and scalability. definition. A workflow process can be executed in a distributed manner over several workflow engines at 2 different sites. A separate workflow log is used at manages interactions between XML-enabled and each site where a Mentor-lite workflow engine is non-XML-enabled systems, EntireX Adapters are running. And a few workflow engines at different pre-build adapters that enable software integration sites can share the same worklist database for with standard applications such as Siebel, SAP and workflow process definition (workflow repository). Vantive. It also can integrate with various databases such as Oracle, Adabas; and other technologies such · The WIDE WFMS as CICS and MQSeries. WIDE is an European Esprit project involving Sema Group, Politencnico di Milano, University of Twente, The four WFMSs reviewed in this Section have ING Bank and the Manresa Hospital[15]. This successfully separated application logic and process project has focused on extending distributed and logic, and they evolved to support distribution active database technologies to the workflow arena. execution of processes. They have different The WFMS system architecture consists of three emphasizes. Exotica/FMQM has focused on using layers, the workflow server layer, basic access layer persistent messages for communication between and the database layer. The workflow engine distributed workflow engines. In the Mentor-lite, provides functionalities to run locally the tasks and attention is concentrated on separating the workflow their activation according to the Workflow schemas kernel functionality from the additional functionality stored in it, including exception support. It also typical of workflow systems, thus supports the interacts with other servers to perform tasks like task incremental integration of workflow technology distribution, remote execution and global transaction within existing business environments. The WIDE management. While Workflow specific data and has focused on extending distributed and active application data are provided by a database database technologies to the workflow product. management system. The interaction between the EntireX is XML-based, and can integrate different workflow engine and the database is through the databases and applications residing in different basic access layer module. platforms. EntireX also provides graphical user interface to enable workflow user to define · EntireX from Software AG processes. EntireX from Software AG is an XML-based workflow