Modeling Service Level Agreements with Linked USDL Agreement

Nowadays, service trading over the Web is gaining momentum. In this highly dynamic scenario, both providers and consumers need to formalize their contractual and legal relationship, creating service level agreements. Although there exist some proposals that provide models to describe that relationship, they usually only cover technical aspects, not providing explicit semantics to the agreement terms. Furthermore, these models cannot be effectively shared on the Web, since they do not actually follow Web principles. These drawbacks hamper take-up and automatic analysis. In this article, we introduce Linked USDL Agreement, a semantic model to specify, manage and share service level agreement descriptions on the Web. This model is part of the Linked USDL family of ontologies that can describe not only technical but also business related aspects of services, incorporating Web principles. We validate our proposal by describing agreements in computational and non-computational scenarios, namely cloud computing and business process outsourcing services. Moreover, we evaluate the actual coverage and expressiveness of Linked USDL Agreement comparing it with existing models. In order to foster its adoption and effectively manage the service level agreement lifecycle, we present an implemented tool that supports creation, automatic analysis, and publication on the Web of agreement descriptions.Junta de Andalucía P12-TIC-1867Ministerio de Economía y Competitividad TIN2012-32273Junta de Andalucía TIC-5906Ministerio de Economía y Competitividad TIN2015-70560-RComisión Europea FP7-ICT 31786

Evolution and overview of Linked USDL

For more than 10 years, research on service descriptions has mainly studied software-based services and provided languages such as WSDL, OWL-S, WSMO for SOAP, and hREST for REST. Nonetheless, recent developments from service management (e.g., ITIL and COBIT) and cloud computing (e.g. Software-as-a-Service) have brought new re- quirements to service descriptions languages: the need to also model business services and account for the multi-faceted nature of services. Business-orientation, co-creation, pricing, legal aspects, and security issues are all elements which must also be part of service descriptions. While ontologies such as e service and e value provided a first modeling attempt to capture a business perspective, concerns on how to contract services and the agreements entailed by a contract also need to be taken into account. This has for the most part been disregarded by the e family of ontologies. In this paper, we review the evolution and provide an overview of Linked USDL, a comprehensive language which provides a (multi-faceted) description to enable the commercialization of (business and technical) services over the web

Towards SLA modeling for RESTful APIs

The term of API Economy is becoming increasingly used to describe the change of vision in how APIs can add value to the organizations. Furthermore, a greater automation of RESTful APIs management can suppose a competitive advantage for the company. New proposals are emerging in order to automatize some API governance tasks and increase the ease of use (e.g. generation of code and documentation). Despite that, the non-functional aspects are often addressed in a highly specific manner or even there not exists any solution for an automatic governance. Nevertheless, these properties are already defined in natural language at the Service Level Agreement (SLA) that both customer and provided have established. In this paper, we carry out a study on the *aaS industry and analyze the current both API modeling and SLA modeling proposals in order to identify the open challenges for an automatic RESTful API governance.Ministerio de Economía y Competitividad TIN2015-70560-RMinisterio de Economía y Competitividad P12–TIC-1867Ministerio de Economía y Competitividad TIN2014-53986-RED

Describing Digital IT Consulting Services:The DITCOS Ontology Proposal and its Evaluation

The digital transformation of the consulting sector has recently gained momentum due to the Covid-19 pandemic. In particular, the areas of financial and insurance services are receiving strong attention from digitization researchers. However, the field of IT consulting itself evaded the attention of scientists. Moreover, despite the heavy use of digital technologies such as on-line conferencing and digital collaboration, the actual consulting process itself has hardly changed. This indicates the weaknesses of IT consulting as a field in establishing true digital business models and consulting service delivery processes. The present paper makes a twofold contribution to the domain of digitization of the IT consulting domain. First, it introduces the DITCOS-O ontology for semantic description of digital IT consulting services. Second, the DITCOS-DN description notation is derived from DITCOS-O, as a new approach to ontology-based definition of domain specific languages. Then, DITCOS-DN is used to describe different real-world services. The result is the analysis of the coverage of real-world service and the comprehensibility of their digitally described service model representations with the help of IT consulting practitioners.</p

Automating SLA-Driven API Development with SLA4OAI

The OpenAPI Specification (OAS) is the de facto standard to describe RESTful APIs from a functional perspective. OAS has been a success due to its simple model and the wide ecosystem of tools supporting the SLA-Driven API development lifecycle. Unfortunately, the current OAS scope ignores crucial information for an API such as its Service Level Agreement (SLA). Therefore, in terms of description and management of non-functional information, the disadvantages of not having a standard include the vendor lock-in and prevent the ecosystem to grow and handle extra functional aspects. In this paper, we present SLA4OAI, pioneering in extending OAS not only allowing the specification of SLAs, but also supporting some stages of the SLA-Driven API lifecycle with an open-source ecosystem. Finally, we validate our proposal having modeled 5488 limitations in 148 plans of 35 real-world APIs and show an initial interest from the industry with 600 and 1900 downloads and installs of the SLA Instrumentation Library and the SLA Engine.Ministerio de Economía y Competitividad TIN2015-70560-RMinisterio de Ciencia, Innovación y Universidades RTI2018-101204-B-C21Ministerio de Educación, Cultura y Deporte FPU15/0298

Using a Work System Metamodel and USDL to Build a Bridge between Business Service Systems and Service Computing

This paper explores the support for more comprehensive modeling of service systems than that possible through modeling methods developed through partial perspectives, with uncertainties about their wider suitability and need for integration with other methods in this domain. It responds to a Dual Call for Papers from INFORMS Service Science and IEEE Transactions on Service Computing requesting contributions that address the barely explored challenge of establishing links between business views of service systems and more technical views from service computing. Competing definitions of service reveal that most business views of service emphasize acts or outcomes produced for others, whereas a service computing view emphasizes encapsulated functionalities that can be discovered and launched by service consumers. This paper uses work system theory (WST) and a related work system metamodel to represent a business view of service systems. It uses the Unified Service Description Language (USDL 2.0) to represent a service computing view of service systems. Application of the business view to the previously defined EU-Rent example illustrates how successively more detailed business-oriented descriptions of a service situation reveal needs for functionality that are well described by USDL. In other words, business service system views and service computing views, as represented by WST and USDL respectively, serve complementary purposes. WST supports modeling and analysis of business situations, while USDL is the basis of detailed descriptions of services as encapsulated functionality

Semantics of Data Mining Services in Cloud Computing

M. Parra-Royon holds a "Excelencia" scholarship from the Regional Government of Andaluc a (Spain). This work was supported by the Research Projects P12-TIC-2958 and TIN2016-81113-R (Ministry of Economy, Industry and Competitiveness - Government of Spain).In recent years with the rise of Cloud Computing (CC), many companies providing services in the cloud, are empowering a new series of services to their catalogue, such as data mining (DM) and data processing (DP), taking advantage of the vast computing resources available to them. Different service definition proposals have been put forward to address the problem of describing services in CC in a comprehensive way. Bearing in mind that each provider has its own definition of the logic of its services, and specifically of DM services, it should be pointed out that the possibility of describing services in a flexible way between providers is fundamental in order to maintain the usability and portability of this type of CC services. The use of semantic technologies based on the proposal offered by Linked Data (LD) for the definition of services, allows the design and modelling of DM services, achieving a high degree of interoperability. In this article a schema for the definition of DM services on CC is presented considering all key aspects of service in CC, such as prices, interfaces, Software Level Agreement (SLA), instances or DM work ow, among others. The new schema is based on LD, and it reuses other schemata obtaining a better and more complete definition of the services. In order to validate the completeness of the scheme, a series of DM services have been created where a set of algorithms such as Random Forest (RF) or KMeans are modeled as services. In addition, a dataset has been generated including the definition of the services of several actual CC DM providers, conforming the effectiveness of the schema.P12-TIC-2958 and TIN2016-81113-R (Ministry of Economy, Industry and Competitiveness - Government of Spain