FACILITATING CO-CONSTRUCTION BY SOCIAL PRACTICE DESIGN: A CASE OF GEODISTRIBUTED EMPLOYEES FACING THE DESIGN OF MODEL-BASED ENTERPRISE SYSTEMS

This paper describes the experiences of practicing social practice design (SPD) activities with user groups, in geographically distributed, collaborating manufacturing companies, struggling with the introduction of model based enterprise systems. Within a European project, we observed and routinely analyzed ongoing development and assessment work of model based technologies and methodologies, in these companies. Based on an ethnographic study of Modelling sessions and Validation sessions, we performed an in depth analysis of people semantic and pragmatic perspectives (a necessary and needed ‘second step back’), and identified core disconnects on modelling concept use and language, and on motivations and goals, between technology designers – modellers - and domain experts – users - clearly hindering project progress -. These disconnects were addressed with user groups in the form of SPD sessions (‘second order’ activities), which consisted mostly in a series of design game and scenario-building workshops, enriched by open conversations and perspective sharing and comparison. The paper describes how these SPD sessions facilitated the creation of sense making and trust, enabling participants to engage and learn, and to act as change agents in the project, opening the way to co-construction of solutions with other actors. Observations of Modelling and Validation sessions showed that participants could not automatically build on a deep understanding of modelling and its trade-offs; they adopted the representational conventions they had learned to use. Lack of sense making and lack of co-construction were observed, along with lack of facilitation for genuinely participative conditions. Modeller-guided Modelling sessions showed no appropriation of object decomposition and relationship structures by domain experts, nor contribution from users to leadership in the modelling process; only imposition of hierarchical structures by modellers, in the midst of a cloud of mistrust and suspicion. Validation sessions of the model-based approach showed that ‘common’ users do not perceive the value of the approach, as they have not been helped to gain a conceptual understanding of modelling, of the tradeoffs of abstractions, and of how a model may productively interact with work practices. In this distributed project, different concepts of various user groups all conflicted with modellers’ concept. The SPD facilitation interventions helped participants in stepping back from the “official view” of the work process created in the course of the project, and in focussing more on their own experiences, opening up for creativity. SPD events were grounded in the belief that, when it comes to one’s own things, people with no special knowledge of the issues to be discussed can contribute something valuable, especially on those matters that they perceive as problems for themselves; it was impressive to witness how people with no management perspective can engage in strategy development within a very short time. The methods were easy enough to adopt without much preparation and rich enough to stimulate learning and valuable insights; people felt comfortable and not at risk at being judged. Participants expressed how important the experience of working creatively on solving “real problems” had been for them. We can understand this also as a result of the longitudinal character of our SPD engagement with people in the project, which had provided us with good knowledge about work practices, potentials and problems on the one hand, allowed trust building on the other hand

HERDING CATS: OR MODEL-BASED ALIGNMENT OF HETEROGENEOUS PRACTICES

This paper reports on a study of how practitioners in engineering design try to develop and use models of the design space of the enterprise in support of collaborative work within global production networks. The paper also examines the difficulties they face in developing these models

An Energy Aware and Secure MAC Protocol for Tackling Denial of Sleep Attacks in Wireless Sensor Networks

Wireless sensor networks which form part of the core for the Internet of Things consist of resource constrained sensors that are usually powered by batteries. Therefore, careful energy awareness is essential when working with these devices. Indeed,the introduction of security techniques such as authentication and encryption, to ensure confidentiality and integrity of data, can place higher energy load on the sensors. However, the absence of security protection c ould give room for energy drain attacks such as denial of sleep attacks which have a higher negative impact on the life span ( of the sensors than the presence of security features. This thesis, therefore, focuses on tackling denial of sleep attacks from two perspectives A security perspective and an energy efficiency perspective. The security perspective involves evaluating and ranking a number of security based techniques to curbing denial of sleep attacks. The energy efficiency perspective, on the other hand, involves exploring duty cycling and simulating three Media Access Control ( protocols Sensor MAC, Timeout MAC andTunableMAC under different network sizes and measuring different parameters such as the Received Signal Strength RSSI) and Link Quality Indicator ( Transmit power, throughput and energy efficiency Duty cycling happens to be one of the major techniques for conserving energy in wireless sensor networks and this research aims to answer questions with regards to the effect of duty cycles on the energy efficiency as well as the throughput of three duty cycle protocols Sensor MAC ( Timeout MAC ( and TunableMAC in addition to creating a novel MAC protocol that is also more resilient to denial of sleep a ttacks than existing protocols. The main contributions to knowledge from this thesis are the developed framework used for evaluation of existing denial of sleep attack solutions and the algorithms which fuel the other contribution to knowledge a newly developed protocol tested on the Castalia Simulator on the OMNET++ platform. The new protocol has been compared with existing protocols and has been found to have significant improvement in energy efficiency and also better resilience to denial of sleep at tacks Part of this research has been published Two conference publications in IEEE Explore and one workshop paper

Quality assessment technique for ubiquitous software and middleware

The new paradigm of computing or information systems is ubiquitous computing systems. The technology-oriented issues of ubiquitous computing systems have made researchers pay much attention to the feasibility study of the technologies rather than building quality assurance indices or guidelines. In this context, measuring quality is the key to developing high-quality ubiquitous computing products. For this reason, various quality models have been defined, adopted and enhanced over the years, for example, the need for one recognised standard quality model (ISO/IEC 9126) is the result of a consensus for a software quality model on three levels: characteristics, sub-characteristics, and metrics. However, it is very much unlikely that this scheme will be directly applicable to ubiquitous computing environments which are considerably different to conventional software, trailing a big concern which is being given to reformulate existing methods, and especially to elaborate new assessment techniques for ubiquitous computing environments. This paper selects appropriate quality characteristics for the ubiquitous computing environment, which can be used as the quality target for both ubiquitous computing product evaluation processes ad development processes. Further, each of the quality characteristics has been expanded with evaluation questions and metrics, in some cases with measures. In addition, this quality model has been applied to the industrial setting of the ubiquitous computing environment. These have revealed that while the approach was sound, there are some parts to be more developed in the future

Report from GI-Dagstuhl Seminar 16394: Software Performance Engineering in the DevOps World

This report documents the program and the outcomes of GI-Dagstuhl Seminar 16394 "Software Performance Engineering in the DevOps World". The seminar addressed the problem of performance-aware DevOps. Both, DevOps and performance engineering have been growing trends over the past one to two years, in no small part due to the rise in importance of identifying performance anomalies in the operations (Ops) of cloud and big data systems and feeding these back to the development (Dev). However, so far, the research community has treated software engineering, performance engineering, and cloud computing mostly as individual research areas. We aimed to identify cross-community collaboration, and to set the path for long-lasting collaborations towards performance-aware DevOps. The main goal of the seminar was to bring together young researchers (PhD students in a later stage of their PhD, as well as PostDocs or Junior Professors) in the areas of (i) software engineering, (ii) performance engineering, and (iii) cloud computing and big data to present their current research projects, to exchange experience and expertise, to discuss research challenges, and to develop ideas for future collaborations