Adaptive development and maintenance of user-centric software systems

A software system cannot be developed without considering the various facets of its environment. Stakeholders – including the users that play a central role – have their needs, expectations, and perceptions of a system. Organisational and technical aspects of the environment are constantly changing. The ability to adapt a software system and its requirements to its environment throughout its full lifecycle is of paramount importance in a constantly changing environment. The continuous involvement of users is as important as the constant evaluation of the system and the observation of evolving environments. We present a methodology for adaptive software systems development and maintenance. We draw upon a diverse range of accepted methods including participatory design, software architecture, and evolutionary design. Our focus is on user-centred software systems

Intelligent Assistance for Software Development and Maintenance

This article presents an architecture for controlled automation in software development environments. Controlled automation enables environments to behave as intelligent assistants by answering questions about the software project and automatically invoking tools to further the users’ goal of producing a working software system. The discussion of the architecture focuses primarily on the programming stages of development and maintenance. An environment assists programmers by understanding the technical aspects of the evolving software system and by actively participating in the programming process. The architecture supports these capabilities by providing two kinds of knowledge representation: (1) the knowledge specific to a particular software project is represented as entities in a database and (2) the knowledge that models programming activities in general is represented as rules amenable to forward and backward chaining. These rules enable an environment to automatically carry out each activity sometime between when its conditions are satisfied and its results are required. The rules are grouped into collections called strategies. One or more specific strategies are employed according to each user’s current context and goals, and determine when forward or backward chaining should be applied and which rules are considered during chaining. This architecture has been validated through a prototype implementation that models the capabilities of an existing environment that supports automation

Recent Developments in Hardware-in-the-Loop Formation Navigation and Control

The Formation Flying Test-Bed (FFTB) at NASA Goddard Space Flight Center (GSFC) provides a hardware-in-the-loop test environment for formation navigation and control. The facility is evolving as a modular, hybrid, dynamic simulation facility for end-tc-end guidance, navigation, and control (GN&C) design and analysis of formation flying spacecraft. The core capabilities of the FFTB, as a platform for testing critical hardware and software algorithms in-the-loop, are reviewed with a focus on many recent improvements. Two significant upgrades to the FFTB are a message-oriented middleware (MOM) architecture, and a software crosslink for inter-spacecraft ranging. The MOM architecture provides a common messaging bus for software agents, easing integration, arid supporting the GSFC Mission Services Evolution Center (GMSEC) architecture via software bridge. Additionally, the FFTB s hardware capabilities are expanding. Recently, two Low-Power Transceivers (LPTs) with ranging capability have been introduced into the FFTB. The LPT crosslinks will be connected to a modified Crosslink Channel Simulator (CCS), which applies realistic space-environment effects to the Radio Frequency (RF) signals produced by the LPTs

S-Net for multi-memory multicores

Copyright ACM, 2010. This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in Proceedings of the 5th ACM SIGPLAN Workshop on Declarative Aspects of Multicore Programming: http://doi.acm.org/10.1145/1708046.1708054S-Net is a declarative coordination language and component technology aimed at modern multi-core/many-core architectures and systems-on-chip. It builds on the concept of stream processing to structure dynamically evolving networks of communicating asynchronous components. Components themselves are implemented using a conventional language suitable for the application domain. This two-level software architecture maintains a familiar sequential development environment for large parts of an application and offers a high-level declarative approach to component coordination. In this paper we present a conservative language extension for the placement of components and component networks in a multi-memory environment, i.e. architectures that associate individual compute cores or groups thereof with private memories. We describe a novel distributed runtime system layer that complements our existing multithreaded runtime system for shared memory multicores. Particular emphasis is put on efficient management of data communication. Last not least, we present preliminary experimental data

A Design Science Research Methodology for Microservice Architecture and System Research

As enterprise continue their Digital journey, Monolithic architecture approach of building Digital platforms has now proven to be inefficient and obsolete. Architectural paradigms in software development are changing with the spinning of time. The paradigms of architecture, formerly considered sufficiently well architecture and even dominant over the years, are now referred to as monolithic. The demands for fresh technology approaches are continuously evolving to cope the new set of business challenges. [25] The purpose of this thesis is to evaluate the approach with an experiment in designing a microservice system. The thesis motivates, presents, demonstrates in use, and evaluates a methodology in microservice system for conducting Design Science (DS) research. Moreover, the thesis will go through in detail description of Microservice architecture and enables us to differentiate and find the right Software Development Methodology (SDM) for the Digital platform. SDM enables the proper management of the software development processes, the project team, products and services in terms of cost effectiveness, time, and quality. [23] The objective of this thesis is to investigate the differences in between architectural paradigms such as monolithic, cloud native and microservice and find the appropriate paradigm that satisfy the enterprises for continuing their digital business. The research of using different platforms and environment for possible improvement on the software development process that enables easy to develop, run and ship distributed application easily and anywhere will be carried out. Similarly, research also focuses on maintaining the development environment consistent, testable and maintainable and hosting the application to the cloud irrespective to underling infrastructure and operation system. The research artifacts will help the enterprises and stakeholders to take an important decision in the selection of the architectural paradigm for their digital platform in advance. The paper concludes that, Microservice architecture is one of the well-known SDM suitable for large enterprise software business application

Energy performance analysis in interdisciplinary education – Lessons learned from a simulation-based teaching approach

The education of building practitioners is challenged by the increasing need for interdisciplinary profiles in the professional practice. To progress toward the goal of a sustainable built environment, a common language must be shared among fields such as architecture and engineering, between which persisting barriers remain. This paper presents an interdisciplinary teaching approach that aimed at getting architecture and engineering students to develop – around a unique case study evolving in parallel to the course – an understanding of the relationships between architectural and constructive aspects, simulation parameters, and energy and thermal comfort performance. Lessons learned from this experience include: the (in)adequacy of using an advanced software (EnergyPlus) imposing a steep initial learning curve, the limitations of working on a case study whose scope extends beyond the context of the class, and the conflict between achieving pedagogical objectives and valuing ‘real-time consultancy’ work in an evolving project. These challenges however seem to have been key to enable students to develop a solid knowledge of the concepts and technical language, as well as strong simulation competences, pushing them to embrace the added value of interdisciplinarity possibly more effectively than if a theoretical exercise had been used.Postprint (author's final draft

Evolving information systems: meeting the ever-changing environment

To meet the demands of organizations and their ever-changing environment, information systems are required which are able to evolve to the same extent as organizations do. Such a system has to support changes in all time-and application-dependent aspects. In this paper, requirements and a conceptual framework for evolving information systems are presented. This framework includes an architecture for such systems and a revision of the traditional notion of update. Based on this evolutionary notion of update (recording, correction and forgetting) a state transition-oriented model on three levels of abstraction (event level, recording level, correction level) is introduced. Examples are provided to illustrate the conceptual framework for evolving information systems

Digital Ecosystems: Ecosystem-Oriented Architectures

We view Digital Ecosystems to be the digital counterparts of biological ecosystems. Here, we are concerned with the creation of these Digital Ecosystems, exploiting the self-organising properties of biological ecosystems to evolve high-level software applications. Therefore, we created the Digital Ecosystem, a novel optimisation technique inspired by biological ecosystems, where the optimisation works at two levels: a first optimisation, migration of agents which are distributed in a decentralised peer-to-peer network, operating continuously in time; this process feeds a second optimisation based on evolutionary computing that operates locally on single peers and is aimed at finding solutions to satisfy locally relevant constraints. The Digital Ecosystem was then measured experimentally through simulations, with measures originating from theoretical ecology, evaluating its likeness to biological ecosystems. This included its responsiveness to requests for applications from the user base, as a measure of the ecological succession (ecosystem maturity). Overall, we have advanced the understanding of Digital Ecosystems, creating Ecosystem-Oriented Architectures where the word ecosystem is more than just a metaphor.Comment: 39 pages, 26 figures, journa