@article {Bruneo20132090,
	title = {Stochastic evaluation of QoS in service-based systems},
	journal = {IEEE Transactions on Parallel and Distributed Systems - IEEE Computer Society},
	volume = {24},
	number = {10},
	year = {2013},
	note = {cited By 7},
	pages = {2090-2099},
	abstract = {<p>WS-BPEL language has become the industrial standard to design and orchestrate modular applications, formalizing service compositions and business relationships among providers and consumers. Once service level agreements (SLAs) among the parties are established, effective tools for evaluating appropriate measurements have to be developed to meet the requirements. However, the design of quality of service (QoS)-guaranteed composed Web services (WSes) still requires several efforts. This work aims at proposing a complete method to study the QoS of a composed WS at design time, i.e., when the process is specified by using WS-BPEL. Starting from the nonfunctional properties of the WS to compose, we propose a technique to derive non-Markovian stochastic Petri net (NMSPN) models from WS-BPEL processes, with the final goal of evaluating parameters such as the service time distribution and the service reliability. To demonstrate the effectiveness of the proposed method and to validate the obtained model, a nontrivial example implementing a travel agency flight reservation process, exposed as a synchronous composed WS, is investigated. {\textcopyright} 1990-2012 IEEE.</p>
},
	keywords = {Business Process, Business relationships, Design, Information services, Non functional properties, Performance, Quality of service, Random access storage, Reliability, Service level agreement (SLAs), Service oriented architecture (SOA), Service time distribution, Stochastic Petri Nets, Web services, WS-BPEL},
	issn = {10459219},
	doi = {10.1109/TPDS.2012.313},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-84883410035\&partnerID=40\&md5=cdebb3fe5a36e131fd3a9485d01fe3c6},
	author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Marco Scarpa}
}
@proceedings {Bruneo2010,
	title = {QoS assessment of WS-BPEL processes through non-Markovian stochastic Petri nets},
	journal = {Proceedings of the 24th IEEE International Symposium on Parallel and Distributed Processing (IPDPS)},
	year = {2010},
	note = {cited By 11; Conference of 24th IEEE International Parallel and Distributed Processing Symposium, IPDPS 2010 ; Conference Date: 19 April 2010 Through 23 April 2010; Conference Code:80843},
	publisher = {IEEE Computer Society},
	address = {Atlanta, GA, United States, 19-23 April 2010},
	abstract = {<p>Service Oriented Architecture (SOA) is the most important and effective software paradigm to design Internet-based services. Using the SOA technology, value-added services can be easily deployed as a combination of existing Web services. In this context, WS-BPEL language has become the SOA industrial standard. To allow services to be composed, business relationships between providers and consumers have to be adequately managed. This implies that a formal definition of Quality of Service (QoS) is agreed and that effective tools for its measurement have to be developed. However, the design ofQoS guaranteed composed Web services still requires several efforts due to the highly distributed nature ofsuch software applications. This work aims at proposing a methodology to evaluate Web service performance at the earliest design phase. We present a novel technique to translate WS-BPEL processes into non-Markovian stochastic Petri nets with the final goal to evaluate parameters such as service time distribution and service reliability. The obtained model can be numerically solved through automatic tools, allowing to investigate the service behavior under different operating conditions and thus helping software engineers to develop QoS-guaranteed software solutions. {\textcopyright} 2010 IEEE.</p>
},
	keywords = {Automatic tools, Business relationships, Computer software, Design, Design phase, Distributed parameter networks, Effective tool, Formal definition, Graph theory, Industrial standards, Information services, Internet-based services, Non-Markovian, Novel techniques, Operating condition, Petri nets, Quality of service, Service oriented architecture (SOA), Service reliability, Service time distribution, Software applications, Software engineers, Software paradigm, Software solution, Stochastic Petri Nets, Stochastic systems, Value added service, Web services, WS-BPEL},
	isbn = {9781424464432},
	doi = {10.1109/IPDPS.2010.5470391},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-77954020712\&partnerID=40\&md5=70790f3d893defcf4e9c792d8b58c5da},
	author = {Dario Bruneo and Salvatore Distefano and Francesco Longo and Marco Scarpa}
}
