This paper addresses quality of service aspects of Web Services (WS) orchestrations created using the Business Process Execution Language for Web Services (BPEL4WS). BPEL4WS is a promising language describing the WS orchestrations in form of Business Processes, but it lacks of a sound formal semantic, which hinders the formal analysis and verification of business processes specified in it. Formal methods, like Petri Nets (PN), may provide a means to analyse BPEL4WS processes, evaluating its performance, detecting weaknesses and errors in the process model already at design-time. A framework for transformation of BPEL4WS into Generalized Stochastic Petri Nets (GSPN)is proposed to analyse the performance and throughput of WS, based on the execution of orchestrated processes.

Business Process Execution Language for Web Services (BPEL4WS) is a promising language describing the Service Oriented Software (SOS) orchestrations in form of Business Processes, but it lacks of a sound formal semantic, which hinders the formal analysis and verification of business processes specified in it. Formal methods, like Petri Nets (PN), may provide a means to analyse BPEL4WS processes, evaluatingits performance, detecting weaknesses and errors in the process model already at design-time. This paper addresses quality of SOS orchestrations created using the BPEL4WS and a framework for transformation of BPEL4WS into Generalized Stochastic Petri Nets (GSPN) is proposed to analise the performance and throughput of SOS, based on the execution of orchestrated processes.

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WS-BPEL Extension for People (BPEL4People) introduces human activity to Web Services Business Process Execution Language (WS-BPEL/BPEL). Some works have been done on the performance verification of WS-BPEL, but there aren't works on the performance verification of WS-BPEL4People. In this paper, we propose a model method for the transformation of WS-BPEL4People/BPEL4People into Generalized Stochastic Petri Nets (GSPN) and this way evaluate its performance. During the transformation, Petri Net is used to model BPEL activities and the human activity of a human task. Then, by validating the generated model, some potential problems with performance of WS-BPEL4People can be detected.

Over the past decade, the fast advance of network technologies, hardware and middleware, as well as software resource sophistication has contributed to the emergence of new computational models. Consequently, there was a capacity increasing for efficient and effective use of resources distributed aiming to integrate them, in order to provide a widely distributed environment, which computational capacity could be used to solve complex computer problems. The two most challenging aspects of distributed systems are resource management and task scheduling. This work contributes to minimize such problems by (i) the use of migration techniques; (ii) implementing a multicore multicluster simulation environment with mechanisms for load balancing with the purpose of analyzing the system in different contexts; (iii) plus, the gang scheduling implementation algorithms will be analyzed through the use of metrics, in order to measure the schedulers performance in different situations. Thus, the results showed a better use of resources, implying operating costs reduction.