Advanced service monitoring configurations with SLA decomposition and selection

Service Level Agreements (SLAs) for Software Services aim to clearly identify the service level commitments established between service requesters and providers. The commitments that are agreed however can be expressed in complex notations through a combination of expressions that need to evaluated and monitored efficiently. The dynamic allocation of the responsibility for monitoring SLAs (and often different parts within them) to different monitoring components is necessary as both SLAs and the components available for monitoring them may change dynamically during the operation of a service based system. In this paper we discuss an approach to supporting this dynamic configuration, and in particular, how SLAs expressed in higher-level notations can be efficiently decomposed and appropriate monitoring components dynamically allocated for each part of the agreements. The approach is illustrated with mechanical support in the form of a configuration service which can be incorporated into SLA-based service monitoring infrastructures

Combinatorial Auction-based Mechanisms for Composite Web Service Selection

Composite service selection presents the opportunity for the rapid development of complex applications using existing web services. It refers to the problem of selecting a set of web services from a large pool of available candidates to logically compose them to achieve value-added composite services. The aim of service selection is to choose the best set of services based on the functional and non-functional (quality related) requirements of a composite service requester. The current service selection approaches mostly assume that web services are offered as single independent entities; there is no possibility for bundling. Moreover, the current research has mainly focused on solving the problem for a single composite service. There is a limited research to date on how the presence of multiple requests for composite services affects the performance of service selection approaches. Addressing these two aspects can significantly enhance the application of composite service selection approaches in the real-world. We develop new approaches for the composite web service selection problem by addressing both the bundling and multiple requests issues. In particular, we propose two mechanisms based on combinatorial auction models, where the provisioning of multiple services are auctioned simultaneously and service providers can bid to offer combinations of web services. We mapped these mechanisms to Integer Linear Programing models and conducted extensive simulations to evaluate them. The results of our experimentation show that bundling can lead to cost reductions compared to when services are offered independently. Moreover, the simultaneous consideration of a set of requests enhances the success rate of the mechanism in allocating services to requests. By considering all composite service requests at the same time, the mechanism achieves more homogenous prices which can be a determining factor for the service requester in choosing the best composite service selection mechanism to deploy

Value Creation through Co-Opetition in Service Networks

Well-defined interfaces and standardization allow for the composition of single Web services into value-added complex services. Such complex Web Services are increasingly traded via agile marketplaces, facilitating flexible recombination of service modules to meet heterogeneous customer demands. In order to coordinate participants, this work introduces a mechanism design approach - the co-opetition mechanism - that is tailored to requirements imposed by a networked and co-opetitive environment

An analysis of the impact of land registration and certification on the sustainable use of farmlands in northwestern Ethiopia : a case study

This study analyses the impact of land registration and certification scheme on sustainable use of farmlands in Debre Mawi and Densa Bahta rural kebeles of Amhara region in northwestern Ethiopia, with a view to contributing to the theoretical debate on tenure security and more realistic policy advocacy on the sustainable use of farmlands. Within the framework of qualitative research methodology, the case study approach helps to observe and understand the relationship between land titling and sustainable use of farmlands in Densa Bahta and Debre Mawi kebeles of the Amhara region in Ethiopia. Specific methods employed were focus group discussions, in-depth interviews and observation, complemented by context analyses of relevant documents. It was found that land titling has contributed to a high perception of security of land tenure among study respondents. However, results show that land titling has both positive and negative impacts on sustainable use of farmlands. The positive impact of land titling is ascribed to its assurance effect and legal obligation imposed on farmers to adopt proper land management practices. The negative impact of land titling arises from its failure to address the existing inequality in possession of farmlands among the village communities. Failure of farmers’ high perceptions of their security of land tenure to translate into sustainable land use practices has implications for the relative importance of productive asset endowments, self-efficacy and risk perception on the sustainable use of farmlands in the Amhara region. Interviewees that follow unsustainable farming practices were endowed with relatively lower pieces of farmland and disadvantaged in possession of other productive assets. They also demonstrated a low level of self-efficacy and a risk-averse attitude to adopting conservation technologies, as they possessed smaller sizes of farmland compared with the village and regional average. The study urges a holistic approach and comprehensive analytical framework to understand the synergy of several factors that affect the sustainable use of farmlands.Environmental SciencesD. Litt. et Phil. (Development Studies

Unbundling tenure issues for urban sanitation development

Urbanisation in sub-Saharan Africa is characterised by a proliferation of informal settlements which all too often embody poverty; low access to basic services and lack secure tenure. The reality of sanitation infrastructure in low and middle income cities is a spectrum of sanitation systems ranging from conventional utility managed systems to basic household facilities. Population growth has outpaced urban planning and provision and, given projected urbanisation trends, a prevalence of non-piped self-build sanitation systems is the most likely scenario for urban sanitation in the developing world, at least for the immediate to mid-term. This presents different governance challenges especially as informal occupations are often on unsuitable land which exacerbates the difficulties in service provision. Sanitation, tenure and development are inextricably linked, not only with respect to these challenges of urbanisation, but also under the strategic objectives of the Millennium Development Goals (MDG). Together sanitation and tenure security are primary indicators of the MDG7, targets ten (access to improved sanitation) and eleven (improving the lives of slum dwellers). The link between sanitation and tenure is the focus of this research. Both tenure and sanitation are fragmented into their component parts to understand exactly how and where they interact. Tenure is defined in terms of formal land tenure; tenure status (to differentiate between landlord and tenant) and tenure security. Sanitation issues are investigated with respect to access, household investment and emptying behaviours. The research framework combines the concept of decision making domains to describe the urban context with a city-wide systems view of sanitation, where both formal and informal institutional arrangements are considered. This research concludes on five main points: firstly, tenure security is a necessary precondition for household investment but, given that urban sanitation development and provision happen largely under the radar of formal city planning and urban management, it is de facto rather than de jure tenure rights that provide the security for household investment in sanitation. The second finding is that few urban sanitation strategies cater for those who are unwilling or unable to invest. This is a fundamental oversight in current urban sanitation strategies of the population segments who cannot invest, thus failing to provide a sanitation strategy for all. This is of growing concern given the type of urbanisation being witnessed in developing countries characterised by increasing concentrations low income populations and tenants. The third finding is that those who are unwilling to invest may be willing to pay (and do) for sanitation services. This places a greater emphasis on downstream and operational sanitation activities (i.e. tenure neutral options). The fourth finding is that there are multiple service providers and majority of urban sanitation transactions take place outside the formal service provision. Giving meaning to these informal transactions is likely to offer insight into improved governance for urban sanitation. The final point is that there is a need to widen the scope of formal sanitation service provision to include tenure neutral sanitation options to reach the needs of tenants and those living with poor tenure security. xiii Practically, this means that by taking a city-wide approach supported by the sanitation cityscape tool which is presented in the thesis one can identify which element(s) of the sanitation system are most appropriate to target given the tenure situation. Without this consideration, urban sanitation interventions are likely to be targeted inappropriately. These conclusions are based upon primary data collected from a household survey (n=363) and a series of key informant interviews collected during 2008 in Greater Dakar, Senegal

Uma proposta de arquitetura de resiliência computacional para infraestruturas baseadas em SOA de empresas virtuais

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia de Automação e Sistemas, Florianópolis, 2019Uma Empresa Virtual (EV) é um tipo de rede colaborativa de organizações na qual grupos de empresas se unem dinâmica, lógica e temporariamente para melhor atender a demandas de mercado. Atuando como se fossem uma única empresa, compartilham recursos, custos e riscos de um negócio, representando assim um proeminente modelo de sustentabilidade, especialmente para pequenas e médias empresas. Uma das pré-condições para atuar numa EV é que os sistemas computacionais dos seus membros interoperem para que os processos de negócio associados à EV possam ser executados sem problemas pelos mais diversos sistemas envolvidos. Esta tese explora um cenário onde todos os sistemas das empresas são implementados de uma forma que possam ser expostos como serviços de software numa perspectiva SOA (Service Oriented Architecture), serem invocados pelos processos de negócio da EV em questão e, ao mesmo tempo, possam ser compartilhados com os outros membros. Desta forma, quando uma EV é formada, um grande sistema distribuído baseado em serviços é dinamicamente criado. Dado que em uma EV novas empresas podem entrar e outras sair ao longo de sua existência, tal sistema não é estático, mas sim deve alterar sua composição, tanto em tempo de projeto, quanto em tempo de execução. Como cada empresa pode participar simultaneamente em mais do que uma EV, isso também significa que cada um dos seus serviços poderá estar envolvido ao mesmo tempo em inúmeras orquestrações, porém em diferentes contextos de negócio e requisitos de qualidade de serviço. Este sistema computacional (e seus inúmeros serviços) deve permanecer operacional ao longo de todo ciclo de vida da EV de forma a sustentar a execução dos processos e, assim, do negócio. Em um sistema como esse, largamente distribuído e com serviços implementados em diferentes tecnologias, várias falhas podem ocorrer. Esta tese propõe uma arquitetura computacional para um sistema de resiliência para esse cenário, fazendo com que o sistema como um todo se recupere diante das falhas e mantenha o nível de qualidade de serviço geral do negócio da EV. Após pesquisa na literatura, não foram encontrados trabalhos que cobrissem a área de intersecção entre resiliência, SOA e EV. Baseado no modelo de referência de computação autonômica MAPE-K, a arquitetura proposta é auto resiliente e foi concebida ela mesma como SOA; portanto distribuída, com baixo acoplamento e escalável. Além disso, seu projeto contempla as modernas visões de economia orientada a serviços, compreendendo ecossistemas de provedores de serviços de software. Para garantir a permanência da EV em operação, várias técnicas consolidadas de tolerância a falhas foram empregadas, combinadas e adaptadas ao cenário em questão, atuando tanto reativamente como proativamente, e respeitando os níveis de responsabilidade das camadas de negócio, TI e de infraestrutura computacional. Um robusto protótipo de software foi implementado como prova de conceito, onde se buscou utilizar o maior número possível de padrões abertos de TI. Ele foi avaliado experimentalmente em um cenário controlado de EV. Ao se aplicar indicadores de desempenho de referência, a arquitetura mostrou-se promissora, suportando a execução dos sistemas da EV na quase totalidade dos casos mesmo diante de inúmeras falhas. A implementação teve algumas simplificações e o desenho da arquitetura partiu de uma série de pressupostos. Ao final, conclusões finais do trabalho são apresentadas bem como um conjunto de trabalhos futuros é sugerido.Abstract: Virtual Enterprises (VE) is a type of collaborative networked organization in which groups of companies are dynamically, logically and temporally joined to better meet market demands. Acting as a single company, they share resources, costs and business risks, thus representing a prominent sustainability model, especially for small and medium-sized enterprises. One of the preconditions for operating as an EV is that the members? IT systems should interoperate in way the business processes associated with EV can be executed by the most diverse involved systems without problems. This thesis exploits a scenario where all company systems are implemented in way they can be exposed as software services in the SOA (Service Oriented Architecture) perspective, being invoked by the VE?s business processes and, at the same time, can be shared with the other members. In this way, when an EV is formed, a large distributed service-based system is dynamically created. Given that new companies can enter and other leave a VE during the general VE process, such system is not static, but rather can change its composition, both at design and run time. Yet, since given companies can participate in many EV simultaneously, this also means that their services can be involved in diverse orchestrations although in different business contexts and quality of services requirements. This computational system (and its many services) should remain operating throughout the VE?s life cycle in order to sustain the execution of the processes and thus of the business. In a system like this, widely distributed and with services implemented in different technologies, several failures can occur. This thesis proposes a resilience system computing architecture for this scenario, making the system able to recover from failures while maintaining the level of general service quality of the VE business. After a literature research, no works were found out that covered the intersection area of resilience, SOA and VE. Based on the MAPE-K autonomic computing reference model, the proposed architecture is self-resilient and was conceived as a SOA itself; therefore, it is distributed, loosely coupled and scalable. In addition, its design adopts the modern vision of service-oriented economy, comprising ecosystems of software service providers. In order to guarantee the VE operation, several fault tolerance techniques were used, combined and adapted to that scenario, acting both reactively and pro-actively, and respecting the responsibility levels of the business, IT and computing infrastructure layers. A robust software prototype was implemented as proof of concept, using as many open IT standards as possible. It was evaluated experimentally in a controlled VE scenario. After the application of reference performance indicators, the architecture showed to be promising, supporting the VE?s systems execution in almost all cases in the presence of numerous failures. The implementation has simplifications and the architecture design has adopted several assumptions. Conclusions are presented in the end, including suggestions for future work

Regional Development Modeling: Theory and Practice

This volume contains a collection of papers presented at IIASA's conference on "Theoretical and Practical Aspects of Regional Development Modelling". Of the 50 papers presented , 26 were selected for publication, in such a way as to strike a balance between theory and application of regional systems analysis. The book is divided into seven parts. After an introduction, the second and third parts contain overviews of current modelling practice and planned economies. In the next two parts, the focus shifts to the theoretical problems encountered in structural and multi-objective analysis of regional systems. The final two sections contain examples of regional development models currently ready for use or in operation and analyze the success of these models in clarifying regional planning and policy problems

Supply Chain

Traditionally supply chain management has meant factories, assembly lines, warehouses, transportation vehicles, and time sheets. Modern supply chain management is a highly complex, multidimensional problem set with virtually endless number of variables for optimization. An Internet enabled supply chain may have just-in-time delivery, precise inventory visibility, and up-to-the-minute distribution-tracking capabilities. Technology advances have enabled supply chains to become strategic weapons that can help avoid disasters, lower costs, and make money. From internal enterprise processes to external business transactions with suppliers, transporters, channels and end-users marks the wide range of challenges researchers have to handle. The aim of this book is at revealing and illustrating this diversity in terms of scientific and theoretical fundamentals, prevailing concepts as well as current practical applications

Overview of Infrastructure Charging, part 4, IMPROVERAIL Project Deliverable 9, “Improved Data Background to Support Current and Future Infrastructure Charging Systems”

Improverail aims are to further support the establishment of railway infrastructure management in accordance with Directive 91/440, as well as the new railway infrastructure directives, by developing the necessary tools for modelling the management of railway infrastructure; by evaluating improved methods for capacity and resources management, which allow the improvement of the Life Cycle Costs (LCC) calculating methods, including elements related to vehicle - infrastructure interaction and external costs; and by improving data background in support of charging for use of railway infrastructure. To achieve these objectives, Improverail is organised along 8 workpackages, with specific objectives, responding to the requirements of the task 2.2.1/10 of the 2nd call made in the 5th RTD Framework Programme in December 1999.This part is the task 7.1 (Review of infrastructure charging systems) to the workpackage 7 (Analysis of the relation between infrastructure cost variation and diversity of infrastructure charging systems).Before explaining the economic characteristics of railway and his basic pricing principles, authors must specify the objectives of railways infrastructure charging.principle of pricing ; rail infrastructure charging ; public service obligation ; rail charging practice ; Europe ; Improverail