A Quality-Driven Approach to Enable Decision-Making in Self-Adaptive Software

Self-adaptive software systems are increasingly in demand. The driving forces are changes in the software “self” and “context”, particularly in distributed and pervasive applications. These systems provide self-* properties in order to keep requirements satisfied in different situations. Engineering self-adaptive software normally involves building the adaptable software and the adaptation manager. This PhD thesis focuses on the latter, especially on the design and implementation of the deciding process in an adaptation manager. For this purpose, a Quality-driven Framework for Engineering an Adaptation Manager (QFeam) is proposed, in which quality requirements play a key role as adaptation goals. Two major phases of QFeam are building the runtime adaptation model and designing the adaptation mechanism. The modeling phase investigates eliciting and specifying key entities of the adaptation problem space including goals, attributes, and actions. Three composition patterns are discussed to link these entities to build the adaptation model, namely: goal-centric, attribute-action-coupling, and hybrid patterns. In the second phase, the adaptation mechanism is designed according to the adopted pattern in the model. Therefore, three categories of mechanisms are discussed, in which the novel goal-ensemble mechanism is introduced. A concrete model and mechanism, the Goal-Attribute-Action Model (GAAM), is proposed based on the goal-centric pattern and the goal-ensemble mechanism. GAAM is implemented based on the StarMX framework for Java-based systems. Several considerations are taken into account in QFeam: i) the separation of adaptation knowledge from application knowledge, ii) highlighting the role of adaptation goals, and iii) modularity and reusability. Among these, emphasizing goals is the tenet of QFeam, especially in order to address the challenge of addressing several self- * properties in the adaptation manager. Furthermore, QFeam aims at embedding a model in the adaptation manager, particularly in the goal-centric and hybrid patterns. The proposed framework focuses on mission-critical systems including enterprise and service-oriented applications. Several empirical studies were conducted to put QFeam into practice, and also evaluate GAAM in comparison with other adaptation models and mechanisms. Three case studies were selected for this purpose: the TPC-W bookstore application, a news application, and the CC2 VoIP call controller. Several research questions were set for each case study, and findings indicate that the goal-ensemble mechanism and GAAM can outperform or work as well as a common rule-based approach. The notable difference is that the effort of building an adaptation manager based on a goal-centric pattern is less than building it using an attribute-action-coupling pattern. Moreover, representing goals explicitly leads to better scalability and understandability of the adaptation manager. Overall, the experience of working on these three systems show that QFeam improves the design and development process of the adaptation manager, particularly by highlighting the role of adaptation goals

Evaluating micro, small and medium-sized enterprises (MSMEs) development programmes in Mexico: a practical participatory approach

This thesis is about a participatory approach to evaluation of development programmes for micro, small and medium-sized enterprises (MSMEs) in Mexico. It advocates the use of intangible factors (stakeholders' claims, concerns and issues) and the participation of stakeholders in the process of evaluation. This evaluation approach could complement conventional approaches used to evaluate programmes for MSMEs in Mexico. In considering these ideas, this research explored the evolution of evaluation identified by Guba and Lincoln and noted some of the problems faced in the evaluation of programmes for MSMEs (e.g. absence of clear objectives, difficulties in expressing the objectives in quantifiable measures and inappropriateness to deal with social behaviour inquiry). This research proposed a shift towards a qualitative evaluation approach and developed a Situationally Responsive Practical Participatory Evaluation (SRPPE) approach. This approach relied upon the accommodation of Guba and Lincoln's Fourth Generation Evaluation and Patton's Utilization-focused evaluation. In this sense, the term accommodation refers to the integration of their methodologies from a practical point of view and their use in parallel from a theoretical point of view. The SRPPE approach considered the claims, concerns and issues (CC&I) of the programme stakeholders as inputs of the evaluation. These refer to the favourable and unfavourable assertions related to the programme and to the declarations of disagreement between stakeholders of the programme. The CC&I are used to analyse components such as decision-making, political, learning and characteristics of the evaluator. The output of the evaluation process promotes conceptual, symbolic and instrumental uses of the evaluation. This approach was tested using a constructivist and interpretivist methodology in which the nominal group technique and focus groups were used to collect information. The information was analysed and interpreted by following a qualitative approach and case studies were used to describe the structure and outcomes of the evaluation of two Mexican programmes for MSMEs. The findings of the research project suggested that an evaluation approach which considered intangible factors helped to understand the programmes, revealed the different views stakeholders had, unveiled conflicts due to different stakeholders' interests and provided a guide towards programme improvement

An application of the concept of messy problems to supply chain management : an investigation of non-standard supply chains in humanitarian logistics

Purpose: This thesis aims to develop a conceptual framework for the management of non-standard supply chains, based upon the concepts of wicked and messy problems and complex adaptive systems, and to validate it in a humanitarian logistics context. Whilst a general theory of wicked and messy problems is in existence, this has not been applied in a supply chain context. Humanitarian logistics presents a complex managerial challenge, in which standard logistics approaches and techniques have been applied with variable success. Here, the underlying generative mechanisms are explored. Design/ Methodology / Approach: This thesis adopts a critical realist approach. A conceptual framework for messy supply chains is developed based on a review of literature on logistics and supply chain management, as well as complex adaptive systems, and wicked and messy problems. This framework is explored in the context of humanitarian logistics. After an initial round of interviews, three case studies were conducted, focusing on humanitarian responses as the unit of analysis. In total, 44 semistructured interviews were conducted. An analysis of findings in each case is followed by the cross-case analysis of key themes, ultimately resulting in a revised framework. Findings: All of the proposed generative mechanisms underlying the messiness in humanitarian logistics are found to be relevant. The challenges for the management of such messy supply chains lie in the behavioural complexity they represent through the mechanisms of sociopolitical impact and the multitude of diverse stakeholder views they encapsulate. Logistics and supply chain management struggles to find holistic management approaches to address such behavioural complexity appropriately. Implications: This research has highlighted the strong element of behavioural complexity that underlies humanitarian logistics and other messy supply chains and is often inadequately addressed by managers and literature alike. The acknowledgement of all the different elements of messiness in humanitarian logistics and other scenarios, as well as the need for holistic management approaches, changes the way in which messy supply chains are seen. The revised conceptual framework presented in this thesis provides a foundation for further study of various messy supply chain contexts. Originality/Value: This thesis provides a novel view of supply chains that are inadequately captured by current frameworks and typologies. As the complexity of supply chain contexts intensifies, behavioural aspects become increasingly important. The framework provided represents a first application of the rich body of literature on wicked and messy problems, as well as complex adaptive systems in supply chain management

System Qualities Ontology, Tradespace and Affordability (SQOTA) Project – Phase 4

This task was proposed and established as a result of a pair of 2012 workshops sponsored by the DoD Engineered Resilient Systems technology priority area and by the SERC. The workshops focused on how best to strengthen DoD’s capabilities in dealing with its systems’ non-functional requirements, often also called system qualities, properties, levels of service, and –ilities. The term –ilities was often used during the workshops, and became the title of the resulting SERC research task: “ilities Tradespace and Affordability Project (iTAP).” As the project progressed, the term “ilities” often became a source of confusion, as in “Do your results include considerations of safety, security, resilience, etc., which don’t have “ility” in their names?” Also, as our ontology, methods, processes, and tools became of interest across the DoD and across international and standards communities, we found that the term “System Qualities” was most often used. As a result, we are changing the name of the project to “System Qualities Ontology, Tradespace, and Affordability (SQOTA).” Some of this year’s university reports still refer to the project as “iTAP.”This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant of Defense for Research and Engineering (ASD(R&E)) under Contract HQ0034-13-D-0004.This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant of Defense for Research and Engineering (ASD(R&E)) under Contract HQ0034-13-D-0004

ACHIEVING AUTONOMIC SERVICE ORIENTED ARCHITECTURE USING CASE BASED REASONING

Service-Oriented Architecture (SOA) enables composition of large and complex computational units out of the available atomic services. However, implementation of SOA, for its dynamic nature, could bring about challenges in terms of service discovery, service interaction, service composition, robustness, etc. In the near future, SOA will often need to dynamically re-configuring and re-organizing its topologies of interactions between the web services because of some unpredictable events, such as crashes or network problems, which will cause service unavailability. Complexity and dynamism of the current and future global network system require service architecture that is capable of autonomously changing its structure and functionality to meet dynamic changes in the requirements and environment with little human intervention. This then needs to motivate the research described throughout this thesis. In this thesis, the idea of introducing autonomy and adapting case-based reasoning into SOA in order to extend the intelligence and capability of SOA is contributed and elaborated. It is conducted by proposing architecture of an autonomic SOA framework based on case-based reasoning and the architectural considerations of autonomic computing paradigm. It is then followed by developing and analyzing formal models of the proposed architecture using Petri Net. The framework is also tested and analyzed through case studies, simulation, and prototype development. The case studies show feasibility to employing case-based reasoning and autonomic computing into SOA domain and the simulation results show believability that it would increase the intelligence, capability, usability and robustness of SOA. It was shown that SOA can be improved to cope with dynamic environment and services unavailability by incorporating case-based reasoning and autonomic computing paradigm to monitor and analyze events and service requests, then to plan and execute the appropriate actions using the knowledge stored in knowledge database