Andy Bond

Supporting business contracts in open distributed systems

Open distributed systems are increasingly used to support business transactions within and across organisations. In order to achieve this goal, fundamental concepts of business practices should be incorporated into a supporting architecture. Support for business contracts can be regarded as an essential ingredient of such an architecture in terms of facilitating more efficient inter-organisational business interactions. This is augmented by the prevailing feeling in business today that global interdependencies are becoming more critical for gaining and maintaining the competitive edge. In this paper we make an initial attempt to identify important contract concepts from economic and legal standpoints and use them to derive a business contract framework. We further discuss how these concepts can be incorporated into an architecture for open distributed processing (ODP).<<ETX>>

An information model for nomadic environments

We present a software architecture which facilitates nomadic computing in an open distributed computing environment. We introduce a model for the description of mobile objects (users, computers and application objects) and their types. The descriptions create an information base for protocols managing mobility of the mobile objects. We present an architecture of servers which extend a distributed computing environment to implement these mobility management protocols.

Domain-specific metamodels for heterogeneous information systems

There is considerable interest in developing distributed information systems on top of legacy systems. Over the last two decades, many issues and solutions have been brought forward pertaining to issues of integration, e.g., schema integration, schema mapping. We have developed a schema mapping framework that features domain-specific metamodels, metamodel-driven schema translation, and semi-automated schema mapping driven by the metamodel. First, we exploit metamodels, i.e., models about models, which transcend heterogeneity among different data models. Second, we enhance them with domain semantics to better express metadata, resulting in less ambiguous information schemas. Third, we develop our own methods of schema translation and schema mapping based on the domain-specific metamodel, capable of a significant degree of semi-automation for convenience and adherence to the metamodel. Finally, our metadata management framework uses metadata repositories that facilitate reuse, interoperability and extensibility. This paper describes our implementation and utilization of domain-specific metamodels within the schema mapping framework that we have developed.

ODSI: enterprise service co-ordination

A challenge for the distributed systems community is to build simple yet flexible environments for composing applications from service components. We need to make the art of software composition available to a broader range of software architects rather than solely technical specialists. Software components are inherently heterogeneous and require infrastructure support for their entire lifecycle of creation, incorporation, alteration, and demise. The ODSI architecture supports the specification and execution of heterogeneous service collaborations based on a shared enterprise model and event-based management infrastructure.

A simple architecture description model

The paper presents a simple composable architecture description model. Components are core modeling concepts. Components describe their relationship with other components by means of interface provision and requirement descriptions. These interfaces define the connectors that structure and compose components together.

Specifying and building interoperable eHealth systems: ODP benefits and lessons learned

This paper describes the experiences of Australias National E-Health Transition Authority in using the RM-ODP to address a number of interoperability challenges in Australian eHealth. The RM-ODP viewpoints provide the separation of concerns across a specification, allowing direct support of independent capability levels within an eHealth community. The RM-ODP provides precise architectural expression, including that of business and policy contexts critical for eHealth. This precision is important for a tools-based architectural approach that supports traceability between requirements, design and implementation. The paper identifies some issues encountered while using the RM-ODP, which provide input into further standardisation efforts.

Meta object approach to database schema integration

Database schema integration is significant not only in building multidatabase systems but also in data warehousing. Meta data, which define schemas, are normally involved in the surrounding issues. And while many of these issues have been addressed in the past, unresolved issues remain. The authors present an approach that not only uses metadata but also uses meta-meta information to make schema integration more possible. Our solution requires a meta object facility that serves not only as a repository but also as a more feasible means of managing meta data. We also advocate the use of such a facility as part of an object oriented middleware environment that provides an open interface standard and several useful services in distributed object management.

Support for mobile computing in open distributed systems

The Reference Model for Open Distributed Processing provides a framework for building distributed heterogeneous applications and creates a good basis for building mobile (ubiquitous) computing applications. We analyse the requirements imposed by mobile computing on distributed environments and characterise adaptability strategies which can be applied in nomadic environments to cope with the quality of service changes due to user, computer or application mobility. We then describe the design of an architecture which extends the ODP architecture to provide support for mobile computing. We characterise the functionality of the architecture, the RPC semantics used for communication in this architecture as well as a prototype built in a CORBA environment.

Visualizing service interaction in an open distributed system

Service interaction in open distributed processing (ODP) environments is difficult to visualize. Interaction often takes place asynchronously and new participants can join the system at any time. If errors are apparent in an interaction, debugging usually takes place through each service involved in the exchange. When peer-to-peer systems involve more than a couple of parties, this technique is often inadequate. This paper describes a tool for visualizing service interaction in a DCE/sup 1/ environment. We combine an event logging service (ELVIN) and an animation tool (WALTER) to provide an, insight into service interaction. Important events are logged by each participant and then animated through a graphical display. These tools have proven useful in both the management and debugging of complex ODP systems.<<ETX>>

Services, Processes and Policies for Digital Health: FHIR&#x00AE; Case Study

This paper provides a number of recommendations for expressing the behavioral semantics of a digital health enterprise. This includes the specification of policies, processes and services, with a particular focus on the RM-ODP enterprise and computational concerns. We believe that these behavioral aspects are needed to complement well developed expression of information semantics. The paper is motivated by the need for better approaches to expressing behaviour in the emerging FHIR® standard and providing a solid architecture framework to practitioners when using FHIR. However, the concepts and ideas are more general and can be applied to other technologies when building digital health solutions.