Maintaining consistency in distributed systems

In systems designed as assemblies of independently developed components, concurrent access to data or data structures normally arises within individual programs, and is controlled using mutual exclusion constructs, such as semaphores and monitors. Where data is persistent and/or sets of operation are related to one another, transactions or linearizability may be more appropriate. Systems that incorporate cooperative styles of distributed execution often replicate or distribute data within groups of components. In these cases, group oriented consistency properties must be maintained, and tools based on the virtual synchrony execution model greatly simplify the task confronting an application developer. All three styles of distributed computing are likely to be seen in future systems - often, within the same application. This leads us to propose an integrated approach that permits applications that use virtual synchrony with concurrent objects that respect a linearizability constraint, and vice versa. Transactional subsystems are treated as a special case of linearizability

Towards a Framework for Developing Mobile Agents for Managing Distributed Information Resources

Distributed information management tools allow users to author, disseminate, discover and manage information within large-scale networked environments, such as the Internet. Agent technology provides the flexibility and scalability necessary to develop such distributed information management applications. We present a layered organisation that is shared by the specific applications that we build. Within this organisation we describe an architecture where mobile agents can move across distributed environments, integrate with local resources and other mobile agents, and communicate their results back to the user

Coping with Problems of Understanding in Interorganizational Relationships: Using Formalization as a Means to make Sense

Research into the management of interorganizational relationships has hitherto primarily focused on problems of coordination, control and to a lesser extent, legitimacy. In this article, we assert that partners cooperating in such relationships are also confronted with ‘problems of understanding’. Such problems arise from differences between partners in terms of culture, experience, structure and industry, and from the uncertainty and ambiguity that participants in interorganizational relationships experience in early stages of collaboration. Building on Karl Weick’s theory of sensemaking, we advance that participants in interorganizational relationships use formalization as a means to make sense of their partners, the interorganizational relationships in which they are engaged and the contexts in which these are embedded so as to diminish problems of understanding. We offer a systematic overview of the mechanisms through which formalization facilitates sensemaking, including: (1) focusing participants’ attention; (2) provoking articulation, deliberation and reflection; (3) instigating and maintaining interaction; and (4) reducing judgment errors and individual biases, and diminishing incompleteness and inconsistency of cognitive representations. In this way, the article contributes to a better understanding of the relationships between formalization and sensemaking in collaborative relationships, and it carries Karl Weick’s thinking on the relationship between sensemaking and organizing forward in the context of interorganizational management.Formalization;Sensemaking;Interorganizational Cooperation;Understanding

A goal-oriented requirements modelling language for enterprise architecture

Methods for enterprise architecture, such as TOGAF, acknowledge the importance of requirements engineering in the development of enterprise architectures. Modelling support is needed to specify, document, communicate and reason about goals and requirements. Current modelling techniques for enterprise architecture focus on the products, services, processes and applications of an enterprise. In addition, techniques may be provided to describe structured requirements lists and use cases. Little support is available however for modelling the underlying motivation of enterprise architectures in terms of stakeholder concerns and the high-level goals that address these concerns. This paper describes a language that supports the modelling of this motivation. The definition of the language is based on existing work on high-level goal and requirements modelling and is aligned with an existing standard for enterprise modelling: the ArchiMate language. Furthermore, the paper illustrates how enterprise architecture can benefit from analysis techniques in the requirements domain

Dynamic System Adaptation by Constraint Orchestration

For Paradigm models, evolution is just-in-time specified coordination conducted by a special reusable component McPal. Evolution can be treated consistently and on-the-fly through Paradigm's constraint orchestration, also for originally unforeseen evolution. UML-like diagrams visually supplement such migration, as is illustrated for the case of a critical section solution evolving into a pipeline architecture.Comment: 19 page

Benefits and swot analysis of iknow estudent services system

The implementation of new robust and complex overall systems in any area is in the very least demanding, complicated, extensive, particularized and delicate. Especially if they are planned to be designed for almost entire higher education system in a country. Inevitably at the beginning, the stakeholders in the existing processes and resources will be reluctant to radical change such as the one in the case of iKnow system implementation, setbacks can be experienced in the mentality shifts, workflow adjustments and adaptation, but also in the different starting points in different institutions for such implementations. And this is only before the beginning of usage of the system. As with any big, ERP-like software solution, the first period of implementation may be the scariest, until everyone gets on board. Then the impressions from the intuitive interface, completion of tasks from distance, the overview of many aspects, maybe never even considered before, and the usefulness of the reports will kick in. That is the point from which the added value from the iKnow eStudent Services System will start to pile up improvements in many directions and depths. This paper can serve as an introduction to the benefits, strengths and opportunities that can be expected from iKnow, and food for thought for the involved parties in the realization of the project for its weaknesses and threats. By observing the requirements for the system on one side, and the technical documentation and the software itself on the other, we can conclude that what is asked for has been delivered in the construction area, and time will show that the objectives will be reachable in the very least, if not completely, with timely implementation and proper usage

Towards a Systematic Repository of Knowledge About Managing Collaborative Design Conflicts

Increasingly, complex artifacts such as cars, planes and even software are designed using large-scale and often highly distributed collaborative processes. A key factor in the effectiveness of these processes concerns how well conflicts are managed. Better approaches need to be developed and adopted, but the lack of systematization and dissemination of the knowledge in this field has been a big barrier to the cumulativeness of research in this area as well as to incorporating these ideas into design practice. This paper describes a growing repository of conflict management expertise, built as an augmentation of the MIT Process Handbook, that is designed to address these challenges.

Evaluating cross-organizational ERP requirements engineering practices: a focus group study

This focus group study presents our first validation of practices for engineering the coordination requirements in cross-organizational Enterprise Resource Planning (ERP) projects. The study evaluates 13 practices addressing a variety of coordination aspects crucial to ERP projects. These practices are results in previously published research publications by the first author. The practices are formulated in response to practitioners' needs at ERP adopting organizations. The proposed practices have now reached the stage where we need some independent feedback as to the extent to which they fit the realities of practitioners. We perform this validation by means of a qualitative research approach, namely the focus group method. Current software engineering literature provides few examples of using focus groups in the evaluation of good software development practices. Because of this, providing reflections on our focus-group-based validation experiences will be of value to both the research community and practitioners

A Software Suite for the Control and the Monitoring of Adaptive Robotic Ecologies

Adaptive robotic ecologies are networks of heterogeneous robotic devices (sensors, actuators, automated appliances) pervasively embedded in everyday environments, where they learn to cooperate towards the achievement of complex tasks. While their flexibility makes them an increasingly popular way to improve a system’s reliability, scalability, robustness and autonomy, their effective realisation demands integrated control and software solutions for the specification, integration and management of their highly heterogeneous and computational constrained components. In this extended abstract we briefly illustrate the characteristic requirements dictated by robotic ecologies, discuss our experience in developing adaptive robotic ecologies, and provide an overview of the specific solutions developed as part of the EU FP7 RUBICON Project

Pattern Reification as the Basis for Description-Driven Systems

One of the main factors driving object-oriented software development for information systems is the requirement for systems to be tolerant to change. To address this issue in designing systems, this paper proposes a pattern-based, object-oriented, description-driven system (DDS) architecture as an extension to the standard UML four-layer meta-model. A DDS architecture is proposed in which aspects of both static and dynamic systems behavior can be captured via descriptive models and meta-models. The proposed architecture embodies four main elements - firstly, the adoption of a multi-layered meta-modeling architecture and reflective meta-level architecture, secondly the identification of four data modeling relationships that can be made explicit such that they can be modified dynamically, thirdly the identification of five design patterns which have emerged from practice and have proved essential in providing reusable building blocks for data management, and fourthly the encoding of the structural properties of the five design patterns by means of one fundamental pattern, the Graph pattern. A practical example of this philosophy, the CRISTAL project, is used to demonstrate the use of description-driven data objects to handle system evolution.Comment: 20 pages, 10 figure