Fine-grain process modelling

In this paper, we propose the use of fine-grain process modelling as an aid to software development. We suggest the use of two levels of granularity, one at the level of the individual developer and another at the level of the representation scheme used by that developer. The advantages of modelling the software development process at these two levels, we argue, include respectively: (1) the production of models that better reflect actual development processes because they are oriented towards the actors who enact them, and (2) models that are vehicles for providing guidance because they may be expressed in terms of the actual representation schemes employed by those actors. We suggest that our previously published approach of using multiple “ViewPoints” to model software development participants, the perspectives that they hold, the representation schemes that they deploy and the process models that they maintain, is one way of supporting the fine-grain modelling we advocate. We point to some simple, tool-based experiments we have performed that support our proposition

On the consequences of acting in the presence of inconsistency

Managing inconsistency in specifications covers a range of activities from consistency checking and inconsistency analysis to inconsistency handling through action. In this paper we argue that inconsistency analysis is insufficient to determine the choice of actions to take in the presence of inconsistency. Rather, we propose that some form of `hypothetical reasoning' is needed in order to determine the consequences of different actions and thereby facilitate the decision-making process. We suggest some logic-based techniques and associated heuristics for analysing the consequences of acting in the presence of inconsistency. 1. Inconsistencies in specifications Deciding what action to take in the presence of inconsistency is difficult. Most researchers agree that eradicating inconsistency in specifications is a desirable and worthy goal, but there is an emerging view that it may also be acceptable to live with inconsistency in certain circumstances or for transient periods of time [..

The Many Facets of Mediation: A Requirements-driven Approach for Trading-off Mediation Solutions

Mediation aims at enabling dynamic composition of multi- ple components by making them interact successfully in order to satisfy given requirements. Through dynamic composition, software systems can adapt their structure and behaviour in dynamic and heterogeneous envi- ronments such as ubiquitous computing environments. This paper pro- vides a review of existing mediation approaches and their key character- istics and limitations. We claim that only a multifaceted approach that brings together and enhances the solutions of mediation from different perspectives is viable in the long term. We discuss how requirements can help identify synergies and trade-offs between these approaches and drive the selection of the appropriate mediation solution. We also highlight the open issues and future research directions in the area

Restructuring requirements specifications for managing inconsistency and change: a case study

This paper describes our experiences in restructuring multi-perspective requirements specifications in order to identify and analyse inconsistencies and manage change. A partial, heterogeneous and reasonably large requirements specification from a NASA project was analysed and decomposed into a structure of "viewpoints", where each viewpoint encapsulates partial requirements of some system components described in the specification. Relationships between viewpoints were identified which included not only the interactions explicitly stated in the requirements but also some implicit and potentially problematic inter-dependencies. The restructuring process and a first informal analysis of the resulting relationships enabled the detection of inconsistencies and the definition of some interesting domain-dependent consistency rules. We believe that this restructuring into viewpoints also facilitated requirements understanding through partitioning, and requirements maintenance and evolution through explicit identification of the inter-viewpoint relationships

INCONSISTENCY HANDLING IN MULTIPERSPECTIVE SPECIFICATIONS

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Viewpoints - a vehicle for method and tool integration

This paper proposes an object-based framework for the development of heterogeneous, composite systems. Such systems require the use of multiple notations and development strategies to describe multiple developer perspectives. The framework employs coarse-grain objects, called ViewPoints, that represent “agents” having “rolesin” and “views-of” a problem domain. These ViewPoints are loosely coupled, locally managed encapsulations, integrated via inter-ViewPoint consistency relations and transformations. Tool integration is treated as a special case of method integration, and is demonstrated by The viewer - a prototype support environment presented in this paper. The viewer supports the proposed framework, and illustrates how ViewPoints may be used for method design, description, integration and use. Developed in Objectworks/Smalltalk, it maps the object-based framework onto an object-oriented implementation. The top level architecture and implementation of The viewer is also briefly presented

Personal Informatics for Non-Geeks: Lessons Learned from Ordinary People

We have been studying how ordinary people use personal informatics technologies for several years. In this paper we briefly describe our early studies, which influenced our design decisions in a recent pilot study that included junior doctors in a UK hospital. We discuss a number of failures in compliance and data collection as well as lessons learned

Expressing The Relationships Between Multiple Views In Requirements Specification

Composite systems generally comprise heterogeneous components whose specifications are developed by many development participants. The requirements of such systems are invariably elicited from multiple perspectives which will overlap, complement and contradict each other. If these requirements are developed and specified using multiple methods and notations respectively, then it is necessary to express and check the relationships between the resultant specification fragments. In this paper we deploy multiple “ViewPoints” that hold partial requirements specifications, described and developed using different representation schemes and development strategies. We discuss the notion of interViewPoint communication in the context of this ViewPoints framework, and propose a general model for such communication. We elaborate on some of the requirements for expressing and enacting inter-ViewPoint relationships, and use fragments of the requirements specification method CORE to illustrate our model

A framework for expressing the relationships between multiple views in requirements specification

Composite systems are generally comprised of heterogeneous components whose specifications are developed by many development participants. The requirements of such systems are invariably elicited from multiple perspectives that overlap, complement, and contradict each other. Furthermore, these requirements are generally developed and specified using multiple methods and notations, respectively. It is therefore necessary to express and check the relationships between the resultant specification fragments. In this paper, we deploy multiple ViewPoints that hold partial requirements specifications, described and developed using different representation schemes and development strategies. We discuss the notion of inter-ViewPoint communication in the context of this ViewPoints framework, and propose a general model for ViewPoint interaction and integration. We elaborate on some of the requirements for expressing and enacting inter-ViewPoint relationships-the vehicles for consistency checking and inconsistency management. Finally, though we use simple fragments of the requirements specification method CORE to illustrate various components of our work, we also outline a number of larger case studies that me have used to validate our framework. Our computer-based ViewPoints support environment, The Viewer, is also briefly described