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El autor José María García ha publicado 8 artículo(s):

1 - Towards a Comprehensive Purchasing Model for Cloud Services

The Cloud Service Market has evolved into a complex landscape that challenges the decision making of users as they develop their purchasing process. In particular, we explore the case of cloud infrastructure (IaaS) providers as an example of heterogeneous variety of purchasing options and discounts; this variability represents an important drawback during the decision making process where there is a need to compare and select the best option. In this work, we define a common model to describe purchasing models from different providers taking into account such heterogeneity. This purchasing model represents a first step towards the automated support of decision making problems during the purchasing process. In order to illustrate our approach we apply the model in a real case study of IaaS purchasing.

Autores: Octavio Martín-Díaz / Pablo Fernandez / José María García / Antonio Ruiz-Cortés / 
Palabras Clave: Cloud Services - Decision Making - Purchasing Options

2 - Priority-Based Human Resource Allocation in Business Processes

Business Process Management Systems (BPMS) are increasingly used to support service composition, typically working with executable BP models that involve resources, which include both automatic services and services provided by human resources. The appropriate selection of human resources is critical, as factors such as workload or skills have an impact on work performance. While priorities for automatic services are intensively researched, human resource prioritization has been hardly discussed. In classical workflow management, only resource assignment at BP design time to select potential performers for activities, and resource allocation at run time to choose actual performers, are considered. There is no explicit consideration of prioritizing potential performers to facilitate the selection of actual performers. It is also disregarded in professional solutions.
In this paper, we address this research gap and provide two contributions: (i) we conceptually define prioritized allocation based on preferences; and (ii) we propose a concrete way in which preferences over resources can be defined so that a resource priority ranking can be automatically generated. Our solution builds on the adaptation of a user preference model developed for the discovery and ranking of semantic web services called SOUP [1] to the domain at hand. As a proof of concept, we have extended the resource management tool CRISTAL (http://www.isa.us.es/cristal) with the SOUP component [2], using RAL [3] for resource selection. 1. J. M. García, D. Ruiz, and A. R. Cortés, «A Model of User Preferences for Semantic
Services Discovery and Ranking,» in ESWC (2), pp. 1­14, Springer, 2010. 2. J. M. García, M. Junghans, D. Ruiz, S. Agarwal, and A. R. Cortés, «Integrating
semantic Web services ranking mechanisms using a common preference model,» Knowl.-Based Syst., vol. 49, pp. 22­36, 2013. 3. C. Cabanillas, M. Resinas, and A. Ruiz-Cortés, «Defining and Analysing Resource Assignments in Business Processes with RAL,» in ICSOC, vol. 7084, pp. 477­486, Springer, 2011.
This work was published in ICSOC 2013, vol. 8274, 374-388. It was partially supported by the EU-FP7, the EU Commission, the Spanish and the Andalusian R&D&I programmes (grants 318275, 284860, TIN2009-07366, TIN2012-32273, TIC-5906).

Autores: Cristina Cabanillas / José María García / Manuel Resinas / David Ruiz / Antonio Ruiz-Cortés / Jan Mendling / 
Palabras Clave:

3 - SOA4All Integrated Ranking A Preference-based, Holistic Implementation

There exist many available service ranking implementations, each one providing ad hoc preference models that offer different levels of expressiveness. Consequently, applying a single implementation to a particular scenario constrains the user to define preferences based on the underlying formalisms. Furthermore, preferences from different ranking implementation’s model cannot be combined in general, due to interoperability issues. In this article we present an integrated ranking implementation that enables the combination of three different ranking implementations developed within the EU FP7 SOA4All project. Our solution has been developed using PURI, a Preference-based Universal Ranking Integration framework that is based on a common, holistic preference model that allows to exploit synergies from the integrated ranking implementations, offering a single user interface to define preferences that acts as a fa¸cade to the integrated ranking implementation.

Autores: José María García / David Ruiz / Antonio Ruiz-Cortés / 
Palabras Clave: Preference Models - Ranking Tools - Semantic Web Services - Systems Integration

4 - Automatic Generation of Purchasing Plans for Cloud Services

The myriad of cloud service providers, as well as their overwhelming variety of configuration and purchasing options, result in a highly complex purchasing scenario. Furthermore, users may specify their needs for cloud services provisioning with a certain scheduling restrictions. There is a need for an automatic support for obtaining an appropriate purchasing plan, which takes into account both service configurations and scheduling needs, while allowing the comparison among different providers and their various offerings. In this work, we present an automatic purchasing plan generator, which analyzes cloud service offerings from several providers to obtain an optimized purchasing plan according to user needs. From the obtained purchasing plan, our solution can provide the corresponding charge plan, possibly including discounts, which serves the purpose of comparing offerings to get the best option.

Autores: Octavio Martín-Díaz / José María García / Pablo Fernandez / Antonio Ruiz-Cortés / 
Palabras Clave: Cloud Services - Discounts - Purchasing Plan

5 - Modeling Service Level Agreements with Linked USDL Agreement (Resumen)

A pesar de la importancia de los servicios en la economía, las tareas como la búsqueda, análisis de alternativas, y contratación de servicios en virtud de acuerdos de nivel de servicio (ANS), siguen realizándose manualmente. En la denominada Web de los servicios existen alternativas para facilitar la automatización de estas tareas basadas en diversos modelos conceptuales: genéricos como Linked USDL, o centrados en algún aspecto concreto, como
WS-Agreement con los ANS. Sin embargo, estos últimos contemplan principalmente sólo aspectos técnicos, sin proporcionar una semántica explícita a los términos del ANS ni cumplir los principios de la Web, dificultando su adopción y análisis automático.

En este artículo presentamos Linked USDL Agreement, una extensión de la familia de ontologías Linked USDL que proporciona facilidades para especificar, gestionar y compartir descripciones de ANS en la Web. Este modelo semántico evita los problemas de interoperabilidad y heterogeneidad de las especificaciones de ANS actuales. Además, dado que nuestro modelo sigue los principios de la Web de los datos, las descripciones de ANS generadas son fácilmente publicables, compartibles y analizables, sirviendo como soporte del ciclo de vida de los servicios.

Nuestra propuesta ha sido validada tanto sobre servicios Web tradicionales (e.g. computación en la nube), como sobre servicios no-computacionales (e.g. outsourcing de procesos de negocio). La comparación realizada con otras alternativas existentes, así como la implementación de una herramienta que facilita la creación, publicación, y análisis automático de documentos en Linked USDL Agreement, nos permite afirmar que nuestra propuesta es capaz de soportar
completamente la gestión del ciclo de vida de los ANS.

Autores: José María García / Pablo Fernandez / Carlos Pedrinaci / Manuel Resinas / Jorge S. Cardoso / Antonio Ruiz Cortés / 
Palabras Clave:

6 -

7 - Automated analysis of cloud offerings for optimal service provisioning (Summary)

Resumen de la contribución

La aparición del paradigma de la computación en la nube ha conllevado un cambio significativo dentro de la industria de las tecnologías de la información, tanto para proveedores de servicios como para los propios consumidores. Así, existen servicios como los de Amazon Elastic Computing Cloud (EC2) o Google Compute Engine que ofrecen computación virtualizada y almacenamiento de recursos (comúmente denominados Infraestructuras como Servicios o IaaS por sus siglas en inglés), de forma que los clientes pueden adquirirlos para reducir los costes de operación de sus sistemas, en comparación con el aprovisionamiento de las mismas infraestructuras de computación en un entorno local. Sin embargo, el aprovisionamiento de servicios en la nube resulta una tarea muy compleja dada la abrumadora variedad de proveedores, configuraciones y opciones de compra disponibles. En este escenario aparecen además diversas dificultades para comparar las ofertas de los distintos proveedores, debido a la heterogeneidad en la descripción de las configuraciones, opciones de compra, o incluso descuentos aplicables. A su vez, las necesidades concretas de los consumidores podrían incluir restricciones adicionales para tener en cuenta una planificación temporal previa en cuanto al número de instancias de IaaS que necesitarán en determinados momentos. Aunque existen algunas herramientas y calculadoras on-line que permiten buscar configuraciones concretas de IaaS, éstas no tienen en cuenta cuestiones como la planificación y la optimización de las opciones de compra. En este trabajo presentamos un framework de análisis automático que es capaz de analizar y comparar ofertas de servicios en la nube de distintos proveedores para obtener un plan de aprovisionamiento óptimo de acuerdo con las necesidades de los consumidores. Dicho plan especifica la cantidad y el tipo de instancias de IaaS que deben adquirirse, junto con la planificación de su uso. Hemos desarrollado un prototipo que ha sido validado en un escenario de virtualización de clases de laboratorio, comparando las opciones de dos proveedores.

Autores: José María García / Octavio Mart??n-D??az / Pablo Fernandez, / Antonio Ruiz-Cortés / Miguel Toro / 
Palabras Clave:

8 - A Service Level Agreement Driven Framework to Customise Cloud Service Billing

Cloud service providers offer to their customers a variety of pricing policies, which range from the simple, yet widely used pay-as-you-go schema to complex discounted models. When executing the billing process, stakeholders have to consider usage metrics and service level objectives in order to obtain the correct billing and conform to the service level agreement in place. The more metrics, discount and compensations rules are added to the pricing schema, the more complex the billing generation results. In this paper we present a monitoring-based solution that enables the dynamically definition of both service level objectives and discount rules, so that providers can customise the billing generation process in terms of the service level agreement they offer. We validate our proposal in a real-world scenario, introducing a micro-service based software solution deployed in a Kubernetes cluster.

Autores: José María García / Octavio Martín-Díaz / Pablo Fernandez / Carlos Müller / Antonio Ruiz-Cortés / 
Palabras Clave: Billing - Cloud Services - Monitoring - Pricing - Service Level Agreements