Marcela Daniele

A method to evaluate QoS of web services required by a workflow

The Web services technology for invoking external applications from a workflow engine provides significant benefits to the WFMS. With the increasing number of web services that provide similar functionality, it is important to find the best web service that meets the users needs, including both their functional and non functional requirements. The non-functional description of the service requires specifying at run time, the quality attributes that can influence the choice of a web service offered by a supplier. In this sense, it is essential to use metrics to evaluate the quality characteristics of Web services (QoS) in order to filter out Web services discovered, and obtain the most suitable one. The dynamic behavior of Web services regarding the development of new services and constantly changing existing ones, requires a continuous evaluation process, leading to capture web service information with respect to their quality and performance evaluation as requested by the workflow. This paper proposes a quantitative measurement method that allows evaluating QoS of web services, and provides a value that allows the comparison and selection that best meets the required characteristics.

Towards an automatic model transformation mechanism from UML state machines to DEVS models

The development of complex event-driven systems requires studies and analysis prior to deployment with the goal of detecting unwanted behavior. UML is a language widely used by the software engineering community for modeling these systems through state machines, among other mechanisms. Currently, these models do not have appropriate execution and simulation tools to analyze the real behavior of systems. Existing tools do not provide appropriate libraries (sampling from a probability distribution, plotting, etc.) both to build and to analyze models. Modeling and simulation for design and prototyping of systems are widely used techniques to predict, investigate and compare the performance of systems. In particular, the Discrete Event System Specification (DEVS) formalism separates the modeling and simulation; there are several tools available on the market that run and collect information from DEVS models. This paper proposes a model transformation mechanism from UML state machines to DEVS models in the Model-Driven Development (MDD) context, through the declarative QVT Relations language, in order to perform simulations using tools, such as PowerDEVS. A mechanism to validate the transformation is proposed. Moreover, examples of application to analyze the behavior of an automatic banking machine and a control system of an elevator are presented.

Metamodel-based transformation from UML state machines to DEVS models

The development of complex dynamic systems require studies and analysis prior to deployment with the goal of detecting unwanted behavior. UML is a language widely used for modeling these systems through state machines, among other mechanisms. Currently, these models do not have appropriate execution and simulation tools to analyze the real behavior of systems. Modeling and simulation for design and prototyping of systems are widely used techniques. In particular, the Discrete Event system Specification (DEVS) formalism separates the modeling and simulation; there are several tools available on the market that run and collect information from DEVS models. This paper proposes a model transformation mechanism of UML state machines to DEVS models in the context MDD, through the declarative QVT Relations language, in order to perform simulations using tools, such as PowerDEVS.

Delayed completion of Final Project of the career Computer Analyst: Seeking its causes

The software development methodologies and modeling techniques simplify the complexity of the software construction. The management of a software project wants to get a quality product, planning, organizing, supervising and controlling the evolution of this project throughout its life cycle. This work stems from a Research and Innovation Project for Improvement of Undergraduate Education that involves four courses of the last year of the course grade Computer Analyst, including the Final Project. This paper intends to address, investigate and identify the causes which make having the methodological tools and training, more teachers with years of experience in delivering these courses and personal monitoring of each group of students who made the Final Project, many cases fail to complete the project within the established planning.

A precise definition of QoS for web services and its application in the invocation of applications from a workflow

The Workflow Reference Model standardizes workflow application development, in order to achieve the interoperability of different workflows. The web services technology allows optimizing the invocation of applications from the workflow engine, so that the workflow engine does not need to know the location of the application to invoke, and that any application can be relocated without involving a change in its invocation. But UDDI, the protocol used to register and locate web services, has some problems in establishing the correspondence between requester requirements and the specifying of services that have the same semantic behavior, even with different syntactic description. Furthermore, in the selection of a web service their quality attributes (QoS) are not considered. This proposal applies to the case study OpenUP/Basic, focusing on the quality attributes of web services for optimal selection and invocation.

Generic Model of the Business Model and Its Formalization in Object-Z

This chapter shows the generic model of the business model, represented graphically with a UML class diagram, product of the analysis of the artifacts that compose the business model and their relationships, according to rational unified process (RUP) (2000). Moreover, the chapter defines a set of rules that the model must verify. It has been demonstrated that graph modeling is useful to visualize, specify, build, and document the artifacts of a system, offering a common language, easy to understand and apply. However, it lacks a precise semantics, which causes problems of ambiguities that in turn generate incorrect or different interpretations. In order to improve upon this, the generic model is translated into a formal specification language. This translation, carried out in Object-Z, allows the expression of a specific business model in a particular domain without ambiguity, and it facilitates the analysis of the properties of the system, showing possible inconsistencies, ambiguities, or incompleteness. IDEA GROUP PUBLISHING This paper appears in the publication, Verification, Validation, and Testing in Software Engineering edited by Aristides Dasso, Ana Funes