Xavier Burgués

Combined Selection of COTS Components

In this paper the problem of the combined selection of COTS components is analyzed in organizations of a specialized nature. This is currently a process of great interest: once many organizations have implemented recently ERP systems for supporting their central management areas, they need to select specialized components for other more particular business areas. We propose a model of combined selection of components based on the distinction of two levels. At the global level the combined selection process takes place, and it includes the initial planning, the enactment of the individual selection processes, the proposal of scenarios to evaluate and the final selection of COTS components. At the local level we locate all the individual selection processes of the different particular business areas, under the supervision of the process at the global level. The model presented here arises from the observation of an ongoing real case.

Towards a Quality Model for the Selection of ERP Systems

ERP systems are a category of COTS products that offers extensive support to the management of business processes in most kind of companies and organizations. Due to their increasing adoption and the risks coming from their incorrect selection, efforts towards effective and reliable selection methods should have a positive impact in the community. This chapter proposes the adoption of quality models as a means for structuring the description of the capabilities of such type of products. The ISO/IEC 9126-1 quality standard is chosen as a framework, and a methodology for tailoring it to this specific domain is followed. The chapter also shows the formalization of the quality model by using a formal language. Last, the use of the quality model for processing quality requirements is also addressed.

Development of service-oriented architectures using model-driven development

ContextModel-Driven Development (MDD) and Service-Oriented Architecture (SOA) are two challenging research areas in software engineering. MDD is about improving software development whilst SOA is a service-based conceptual development style, therefore investigating the available proposals in the literature to use MDD when developing SOA may be insightful. However, no studies have been found with this purpose. ObjectiveThis work aims at assessing the state of the art in MDD for SOA systems. It mainly focuses on: what are the characteristics of MDD approaches that support SOA; what types of SOA are supported; how do they handle non-functional requirements. MethodWe conducted a mapping study following a rigorous protocol. We identified the representative set of venues that should be included in the study. We applied a search string over the set of selected venues. As result, 129 papers were selected and analysed (both frequency analysis and correlation analysis) with respect to the defined classification criteria derived from the research questions. Threats to validity were identified and mitigated whenever possible. ResultsThe analysis allows us to answer the research questions. We highlight: (1) predominance of papers from Europe and written by researchers only; (2) predominance of top-down transformation in software development activities; (3) inexistence of consolidated methods; (4) significant percentage of works without tool support; (5) SOA systems and service compositions more targeted than single services and SOA enterprise systems; (6) limited use of metamodels; (7) very limited use of NFRs; and (8) limited application in real cases. ConclusionThis mapping study does not just provide the state of the art in the topic, but also identifies several issues that deserve investigation in the future, for instance the need of methods for activities other than software development (e.g., migration) or the need of conducting more real case studies.

LEARN-SQL: Automatic Assessment of SQL Based on IMS QTI Specification

In this paper we present LEARN-SQL, a system conforming to the IMS QTI specification that allows on-line learning and assessment of students on SQL skills in an automatic, interactive, informative, scalable and extensible manner.

Improving the accuracy of UML metamodel extensions by introducing induced associations

In the process of extending the UML metamodel for a specific domain, the metamodel specifier introduces frequently some metaassociations at MOF level M2 with the aim that they induce some specific associations at MOF level M1. For instance, if a metamodel for software process modelling states that a “Role” is responsible for an “Artifact”, we can interpret that its specifier intended to model two aspects: (1) the implications of this metaassociation at level M1 (e.g., the specific instance of Role “TestEngineer” is responsible for the specific instance of Artifact “TestPlans”); and (2) the implications of this metaassociation at level M0 (e.g., “John Doe” is the responsible test engineer for elaborating the test plans for the package “Foo”). Unfortunately, the second aspect is often not enforced by the metamodel and, as a result, the models which are defined as its instances may not incorporate it. This problem, consequence of the so-called “shallow instantiation” in Atkinson and Kühne (Procs. UML’01, LNCS 2185, Springer, 2001), prevents these models from being accurate enough in the sense that they do not express all the information intended by the metamodel specifier and consequently do not distinguish metaassociations that induce associations at M1 from those that do not. In this article we introduce the concept of induced association that may come up when an extension of the UML metamodel is developed. The implications that this concept has both in the extended metamodel and in its instances are discussed. We also present a methodology to enforce that M1 models incorporate the associations induced by the metamodel which they are instances from. Next, as an example of application we present a quality metamodel for software artifacts which makes intensive use of induced associations. Finally, we introduce a software tool to assist the development of quality models as correct instantiations of the metamodel, assuring the proper application of the induced associations as required by the metamodel.

A MOF-compliant approach to software quality modeling

Software quality is a many-faceted concept that depends on the kind of artifact to be measured, the context where measurement takes place, the quality framework used, and others. Furthermore, there is a great deal of standards, white papers, and in general proposals of any kind related to software quality. Consequently, a unified software quality framework seems to be needed to compare, combine or select these proposals and to define new ones. In this paper we propose a MOF-compliant approach for structuring quality models in order to formalise software quality issues and deal with quality information modelling. We propose two types of models: a generic model, situated in the M2 MOF layer; and a hierarchy of reference models, defined in the Ml and M0 MOF layers. The generic model elements are derived from the UML meta-model by specialization. Then, we can instantiate them to get reference models that formalise (combinations of) existing proposals which may be further refined for defining quality frameworks to be used in different experiences. Each of these models is divided into three parts, namely fundamental concepts, metrics and context. We illustrate our proposal providing a multi-level reference model in the context of collection libraries quality evaluation.

Inducing Metaassociations and Induced Relationships

In the last years, UML has been tailored to be used as a domain-specific modelling notation in several contexts. Extending UML with this purpose entails several advantages: the integration of the domain in a standard framework; its potential usage by the software engineering community; and the existence of supporting tools. In previous work, we explored one particular issue of heavyweight extensions, namely, the definition of inducing meta-associations in metamodels as a way to induce the presence of specific relation-ships in their instances. Those relationships were intended by the metamodel specifier but not forced by the metamodel itself. However, our work was restricted to the case of induced associations. This paper proposes an extension to the general case in which inducing metaassociations may force the existence of arbitrary relationships at M1. To attain this goal, we provide a general defini-tion of inducing metaassociation that covers all the possible cases. After revisi-ting induced associations, we show the inducement of the other relationship types defined in UML: association classes, generalization and dependencies.

QUINST: A Metamodeling Tool

We present a metamodeling tool to support a modeling methodology which we have succesfully applied in the field of software quality. As a distinguishing and general purpose functionality, it implements the concept of induced associations, which are introduced by the tool when the user instantiates metaclasses related by inducing metaassociations in the metamodel.