Richard McClatchey

A Distributed Workflow and Product Data Management Application for the Construction of Large Scale Scientific Apparatus

Recently there has been much discussion about workflow management for computer-based systems. Workflow management allows business managers to coordinate and schedule activities of organisations to optimise the flow of information or operations between the resources of the organisation. Scientific and engineering applications are also being viewed as potential areas in which the principles of workflow management can be applied. Scientific applications, however, present particular problems of workflow management. Not only do the workflow definitions change frequently [VWW96, ER95] but their refinement may only take place as a result of experimentation as the workflow process itself is followed. For these reasons and others commercial workflow management systems appear to be inadequate for the purposes of managing scientific workflow management applications.

Workshop on workflow management in scientific and engineering applications—report

On the 1st and 2nd of September a workshop was staged at the 8th international conference on Database and Expert Systems Applications (DEXA97) in Toulouse, France. The workshop was entitled Workflow Management in Scientific and Engineering Applications and was organized by Richard McClatchey of the Complex Cooperative Systems research center at the University of the West of England (UK) and by Gottfried Vossen of the University of Muenster (Germany). The workshop followed up many issues raised at the NATO Advanced Studies Institute on Workflow Management and Interoperability held in August in Istanbul and in particular was aimed at dynamic or ad-hoc aspects of workflow management which come to light in engineering or scientific applications.

The use of an object repository in the configuration of control systems at CERN

The CERN-based CICERO project is creating a general purpose Control Information System (named Cortex) which will enable physicists and technicians in integrating computer control systems across computer networks using standard protocols and interfaces. Cortex has two major functionalities: a configuration based tool for describing the components to be connected and their interfaces, and an on-line message passing system. An Object Oriented Database is seen as an essential feature of such a system, both for the control system configuration process and to provide information for the on-line system. This paper reports on an investigation into the requirements for the use of an Object repository in providing these features. The requirements are compared to the functionality provided by a set of current, stable commercially available Object Oriented Databases, to demonstrate areas where features need to be developed, either by the application programmer or the database developers.

Managing separation of concerns in grid applications through architectural model transformations

Grids enable the aggregation, virtualization and sharing of massive heterogeneous and geographically dispersed resources, using files, applications and storage devices, to solve computation and data intensive problems, across institutions and countries via temporary collaborations called virtual organizations (VO) as described in [1]. Most implementations result in complex superposition of software layers, often delivering low quality of service and quality of applications. As a consequence, Grid-based applications design and development is increasingly complex, and the use of most classical engineering practices is unsuccessful. Not only is the development of such applications a time-consuming, error prone and expensive task, but also the resulting applications are often hard-coded for specific Grid configurations, platforms and infrastructures. Having neither guidelines nor rules in the design of a Grid-based application is a paradox since there are many existing architectural approaches for distributed computing, which could ease and promote rigorous engineering methods based on the re-use of software components. It is our belief that ad-hoc and semiformal engineering approaches, in current use, are insufficient to tackle tomorrow’s Grid developments requirements. Because Grid-based applications address multidisciplinary and complex domains (health, military, scientific computation), their engineering requires rigor and control. This paper therefore advocates a formal model-driven engineering process and corresponding design framework and tools for building the next generation of Grids. To achieve these objectives, two approaches are combined: (1) a formal semantic is used to model and check Grid applications; (2) a model-driven approach is adopted to promote model re-use, through separation of concerns, to model transformations, to hide the platform complexity and to refine abstract software descriptions into concrete usable ones.

Integrating Product Data with Workflow Data in Enterprise Models

Enterprises need to cope with increasing volumes of complex and evolving data and at the same time to reduce ‘time-to-market’ for products. As data volumes increase and user communities grow and change with time, enterprise systems must be able to provide access to the enterprise data appropriate to multiple application ‘viewpoints’. In addition, the enterprise model must be flexible, adaptable and secure and be designed to maximise reusability of code, to cope with distribution of the enterprise activities and to inter-operate with existing legacy systems. The era where business rules are buried deep within the application code is coming to an end. Today users themselves seek to dynamically change their business rules and they need systems which can adapt to their evolving business needs, meet their requirements and scale to large installations. This paper outlines how an enterprise model that integrates process and product data modelling has been constructed following a description-driven design approach for the management of large-scale scientific apparatus construction.

Explicit modeling of the semantics of large multi-layered object-oriented databases

Description-driven systems based on meta-objects are an increasingly popular way to handle complexity in large-scale object-oriented database applications. Such systems facilitate the management of large amounts of data and provide a means to avoid database schema evolution in many settings. Unfortunately, the description-driven approach leads to a loss of simplicity of the schema, and additional software behaviour is required for the management of dependencies, description relationships, and other Design Patterns that recur across the schema. This leads to redundant implementations of software that cannot be handled by using a framework-based approach. This paper presents an approach to address this problem which is based on the concept of an ontology of Design Patterns. Such an ontology allows the convenient separation of the structure and the semantics of database schemata. Through that, reusable software can be produced which separates application behaviour from the database schema.

Methods and standards in the design of control information systems

Abstract With the advent of standards in distributed object technology, it is now feasible to reuse control objects in a deterministic manner across control systems. The CERN-based CICERO project aims to use object-oriented methods to design the main building blocks of a generic control information system to be based on the distributed object standard CORBA (CORBA 1992). CICERO is producing an integrating environment (Cortex, Barillere 1994a) into which distributed user control objects will ultimately be ‘plugged and played’ and a supporting information system for the configuration and management of that environment Cortex has been designed to be sufficiently generic in nature to allow its use both in scientific and industrial applications.