Hirotaka Hara

Distributed workflow management system for electronic commerce

We describe a new architecture and protocol that we have developed to meet the requirements of workflow systems that are used for electronic commerce systems among enterprises. We developed practical electronic commerce systems using XML-based workflow systems among enterprises. We found that the requirements are greatly different from traditional workflow systems in some points; such as process management, server communication protocol, history log management, data conversion, and external application calls. In this paper, we illustrate the new requirements and problems when EC systems are developed using traditional workflow architecture and protocols, then we propose our new architecture and protocol that provide solutions for these requirements and problems. In this architecture based on XML, servers have the server communication module and the external-call module. The server commutation module provides a way to make a batch request. The external-call module provides a reliable way to call business applications. We also presented a retrying algorithm that maintains consistency between a workflow engine and an external application. The logging server provides a stable and fast way to query logs by collecting events from workflow servers. Our new protocol is being proposed of WfMC (WorkFlow Management Coalition) as an extension of Wf-XML.

Model-based architecture for the Intranet

We propose a system called CEE (Cooperative Environment for Enterprise-computing) which is based on a new architecture for the Intranet. CEE works based on the enterprise model which consists of the organization, business function/process conforming to IDEFO, and resources such as persons and documents. CEE integrates enterprise information and applications based on the enterprise model and enable the following functions on the WWW. 1) CEE automatically generates and maintains WWW pages and links according to business objects in the enterprise model. 2) CEE manages documents linked to the enterprise model and provides check-in/out and version control functions. 3) CEE promotes concurrent engineering by providing notification on the creation or modification of the output document of a process to the succeeding processes. 4) CEE provides document-based project management on the IDEFO chart in addition to traditional time-based project management on the Gantt chart.

Enterprise model-based software architecture with server component integration

Many companies are seeking new information systems that support more business activities than current systems. Such a system should enable more rapid information collection and sharing, and promote increased automation. Furthermore, there is a strong technological demand for the integration of various business systems and rapid modification of business processes and rules embedded in the system. To meet this demand, we propose enterprise model-based software development and associated software architecture with integrated server components. An experimental but practical system has been developed and evaluated in projects located in various countries. This paper discusses the viability of enterprise model-based software architecture with integrated server components such as a business application system, a Web server, a workflow server, and a directory server.

An optimistic method for updating information in distributed collaborative work

Proposes a new method for updating information in distributed collaborative work. The effective performance of collaborative work distributed among several locations requires that information be replicated and freely updated in each distributed server. This is difficult to achieve with existing information-sharing methods such as the WWW and workflow. Our optimistic lock control method enables the direct updating of replicated information in any server while maintaining consistency among all the servers. A server failure is not critical to other servers because there is no master server. This method differs from the traditional master-slave method in which updates are performed in a specific master server. This paper also addresses the dynamic deployment of a new server. Our method is being used on a trial basis for an international software development project between Japan and India.

Practical experiences of designing a distributed collaborative system

The PI-CEE(Project Information Cooperative Enterprise Environment) system is a project information management system that uses Java applications and is based on the model-based distributed collaborative work support concept. It is designed to achieve optimal performance with model-based Java applications for application to large-scale projects. We applied the first prototype of PI-CEE to a large-scale project. The result was twofold: memory use and response time worsened with increases in data quantity. Our design concept is based on doing four things: designing a server transaction system and database, implementing client cache management, making improvements in server-client communication, and multiple-server replication. We discuss our system, the general lessons that we learned from its application, and the problems we encountered and their resolutions.

Performance evaluation for parallel mixed-integer linear programming system

We implemented a parallel mixed-integer linear programming system and evaluated performance on a parallel computer with shared memory. Mixed-integer programming systems are implemented by branch-and-bound (B&B) and simplex algorithms in commercial systems. The system can solve problems including both integers and real variables in linear equations. Problems are solved by generating linear programming (LP) relaxation problems in the B&B algorithm and applying them to simplex algorithms. The parallel mixed-integer linear programming system is written in about 4,000 lines of C. In the initial problem solving stage, the system searches a tree using a depth-first strategy to find an incumbent solution as soon as possible. After the system finds an initial solution, it carries out branch cut processing using a breadth-first strategy. If the queue list managing the subproblem executed by simplex algorithm is empty, the incumbent is the optimal solution. We applied parallel programming to the search using a bread...

An assumption-based combinatorial optimization system

An assumption-based combinatorial optimization system is proposed for solving combinatorial optimization problems. The assumption-based combinatorial optimization system is a local search method in which a solution is formulated as a set of assumptions. Minimal support for the objective function is a minimal set of assumptions that guarantee the value of the objective function. Using minimal support, the system finds an approximate optimal solution efficiently because it: reduces the number of neighbors, defends the loop of a search and prunes search space, and never stays at a local optimal solution. The system was applied to a jobshop scheduling problem, and the systems effectiveness compared with other methods was demonstrated.<<ETX>>