Managing dependency relations in inter-organizational models

In various fields like software development, information systems development, and e-business development, model-based approaches allow specifying different models of which each emphasizes one specific aspect or part of the software system. In this thesis we consider particularly model-based approaches for defining inter-organizational cooperations. These cooperations are usually complex in terms of coordination, agreements, and value creation for involved partners.\ud \ud At design time one should ensure that the different models are consistent with each other, i.e., that they describe the same system. At runtime we additionally have to deal with the fact that behavior of the software system might be different from that agreed upon. Such deviant behavior can, for example, be caused by partners in the cooperation that do not behave according to the agreement. Therefore, the challenges are to ensure consistency at design time as well as to monitor the system at runtime in order to detect inconsistencies with the models it relies on.\ud \ud When managing complex cooperations, it is also vital to maintain the models describing them to keep an overview on the successfulness of the cooperation. Changing one model to regain consistency with the running system might result in new inconsistencies between the different models. As a consequence, this maintenance phase of the models is time consuming and grows in complexity with increasing number of models describing the system. \ud \ud This thesis proposes a method that supports ensuring and maintaining consistency between running system and underlying models for inter-organizational cooperations. We provide a structured and model-independent approach to check and maintain consistency. Thereby, we focus on identifying and maintaining these inter-model relations.\ud \ud We validate our method by conducting two case studies in two different fields of research. The first scenario deals with business and coordination models, while the second one addresses Web service compositions. Furthermore, we provide a prototypical implementation as proof-of-concept evaluation of both scenarios. We conclude with an empirical validation of the Web service composition scenario by an extensive and interactive survey conducted among 34 participants. This survey confirms the suitability of our proposed management solution provided for real life use

Towards Management of Complex Service Compositions

Many companies offer physical products combined with on-line services. For example, product configuration, ordering, order tracking, and payments can be done on-line. The service part of the total offering (the composition) is typically composed of services offered by providers where performance of both the composition (provided by the company) and the input services (obtained from providers) is governed by service level agreements (SLAs). The goal of our approach is to diagnose the performance of an on-line service composition in terms of the performance of on-line input services, with respect to the performance indicators mentioned in the SLAs, and to do this in real-time. Classical SLA monitoring techniques are batch-oriented and are not usable in the highly dynamic environment of Web service provision, where provider relations may change even during service delivery. Our techniques use real-time analysis of log files to trace and diagnose performance on-the-fly. Current Web service monitoring techniques do not relate a composite service to its components, as needed to provide diagnostic information. Furthermore, current approaches do not take into account that the dependency of a composition on its components varies for different attributes (such as cost and response time). In this paper we propose to extend our previous research in this area by lifting a number of simplifying assumptions to make the approach applicable in real-life, and by extending our study to frequently used SLAs in practice

MaDe4IC: an abstract method for managing model dependencies in inter-organizational cooperations

Inter-organizational cooperations are complex in terms of coordination, agreements, and value creation for involved partners. When managing complex cooperations, it is vital to maintain models describing them. Changing one model to regain consistency with the running system might result in new inconsistencies. As a consequence, this maintenance phase grows in complexity with increasing number of models. In this context, challenges are to ensure consistency at design time and to monitor the system at runtime, i.e., at design time, consistency between different models describing the cooperation needs to be ensured. At runtime, behavior of the software system needs to be compared with its underlying models. In this paper, we propose a structured and model-independent method that supports ensuring and maintaining consistency between running system and underlying models for inter-organizational cooperations

Monitoring Dependencies for SLAs: The MoDe4SLA Approach

In service oriented computing different techniques for monitoring Service Level Agreements (SLAs) are available. Many of these monitoring approaches focus on bilateral agreements between partners. However, when monitoring composite services it is not only important to figure out whether SLAs are violated, but we also need to analyze why these violations have occurred. When offering a composite service a company depends on its content providers to meet the service level they agreed upon. Due to these dependencies a company should not only monitor the SLA of the composite service, but also the SLAs of the services it depends on. By analyzing and monitoring the composite service in this way, causes for SLA violations can be easier found. In this paper we demonstrate how to analyze SLAs during development phase and how to monitor these dependencies using event logs during runtime. We call our approach MoDe4SLA (Monitoring Dependencies for SLAs)

Monitoring Service Compositions In MoDe4SLA: Design of Valdiation

In previous research we introduced the MoDe4SLA approach for monitoring service compositions. MoDe4SLA identifies complex dependencies between Service Level Agreements (SLAs) in a service composition. By explicating these dependencies, causes of SLA violations of a service might be explained by malfunctioning of the services it depends on. MoDe4SLA assists managers in identifying such causes. In this paper we discuss how to evaluate our approach concerning usefulness for the user as well as effectiveness for the business. Usefulness is evaluated by experts who are asked to manage simulated runs of service compositions using MoDe4SLA. Their opinion on the approach is an indicator for its usefulness. Effectiveness is evaluated by comparing runtime results of SLA management using MoDe4SLA with runtime results of unsupported management. Criteria for effectiveness are cost reduction and increase in customer satisfaction

On formalising dialogue systems for argumentation in the event calculus

This paper studies the logical formalisation and implementation of dialogue systems for argumentation, motivated by the claim that this benefits their formal investigation and implementation. A case study is described in which a dialogue system of Prakken is formalised in Shanahan’s version of the ‘full ’ Event Calculus and then implemented as a Prolog program. Then a second case study is briefly summarised in which a dialogue system of Parsons, Wooldridge and Amgoud is formalised in the same way. From the case studies some conclusions are drawn on the usefulness of the formalisation method

Pruebas inmunológicas e inmunohistoquímicas en Medicina Bucal. Parte II

En este segundo artículo sobre las pruebas inmunológicas e inmunohistoquímicas utilizadas en Medicina Bucal, se revisan los métodos de detección de antígenos o anticuerpos específicos de diversas enfermedades no necesariamente autoinmunes, también las técnicas de identificación de linfocitos T o B, los análisis de las funciones efectoras de los linfocitos, las pruebas de inmunotluorescencia y algunos tests diagnósticos específicos