Pedro Valderas

Towards the Model Driven Development of context-aware pervasive systems

In this work, we introduce a Model Driven Development method for developing context-aware pervasive systems. This method allows us to specify a context-aware pervasive system at a high level of abstraction by means of a set of models, which describes both the system functionality and the context information. From these models, an automated code generation strategy is applied. This strategy allows us to generate the system Java code that provides the system functionality and as well as an OWL specification that represents the context information and allows us to manage this information without additional burden. Furthermore, this specification is used by a reasoner at runtime to infer context knowledge that is not directly observable, and it is also used by machine learning algorithms to give support to the system adaptation according to the context information.

A Survey of Requirements Specification in Model-Driven Development of Web Applications

Model-driven development has become more and more important in the last few years. In the context of web application development, many web Engineering methods that propose model-driven development processes have appeared. However, earlier stages of these processes are seldom considered and few of these methods rigorously face the problems of specifying web application requirements and translating them into the proper conceptual model. However, it is widely recognized that requirements engineering activities are essential to obtain quality software products. This article surveys Model-driven web engineering methods in a comparative study and analyzes the techniques proposed for specifying functional, data and navigational requirements as well as the mechanisms provided for automatically translating these requirements into conceptual models. Our main goal is to provide a critical view of the support that is provided by these methods for handling web application requirements in order to show their current limitations and strengths.

A transformational approach to produce web application prototypes from a web requirements model

There are a significant number of proposals for modelling and developing web applications, but very few of them rigorously deal with how to elicit and represent requirements, and how to go from the Requirements Model to the Conceptual Model with a sound methodological basis. This work presents an approach to capture web application requirements. The main goal of this approach is to provide analysts with techniques that allow them to specify not only the functional and data requirements of a web application but also the navigational ones at early stages. These techniques make it possible to identify, specify and describe every task that must be achieved by web application users. In addition, we introduce a strategy based on graph transformations that allow us to automate the derivation of the navigational model of the OOWS method from early requirements specifications. Finally, by using the OOWS automatic code capabilities, we show how this graph transformations-based strategy allows us to obtain web applications prototypes from early requirements specifications.

Introducing requirements traceability support in model-driven development of web applications

In this work, we present an approach that introduces requirements traceability capabilities in the context of model-driven development of Web applications. This aspect allows us to define model-to-model transformations that not only provide a software artifact of lower abstraction (as model-to-model transformations usually do) but also to provide feedback about how they are applied. This feedback helps us to validate whether transformations are correctly applied. In particular, we present a model-to-model transformation that allows us to obtain navigational models of the Web engineering method OOWS from a requirements model. This transformation is defined as a set of mappings between these two models that have been implemented by means of graph transformations. The use of graph transformations allows us to develop a tool-supported strategy for applying mappings automatically. In addition, mechanisms for tracing requirements are also included in the definition of graph transformations. These mechanisms allow us to link each conceptual element to the requirements from which it is derived. In particular, we focus on tracing requirements throughout the navigational model, which describe the navigational structure of a Web application. To take advantage of these traceability mechanisms, we have developed a tool that obtains traceability reports after applying transformations. These reports help us to study aspects such as whether requirements are all supported, the impact of changing a requirement, or how requirements are modelled.

Supporting runtime system evolution to adapt to user behaviour

Using a context-aware approach, we deal with the automation of user routines. To do this, these routines, or user behaviour patterns, are described using a context model and a context-adaptive task model, and are automated by an engine that executes the patterns as specified. However, user behavior patterns defined at design time may become obsolete and useless since users needs may change. To avoid this, it is essential that the system supports the evolution of these patterns. In this work, we focus on supporting this evolution by confronting an important challenge in evolution research: raise the level in which evolution is applied to the modelling level. We develop mechanisms to support the pattern evolution by updating the models at runtime. Also, we provide end-users with a tool that allows them to carry out the pattern evolution by using user-friendly interfaces.

From web requirements to navigational design – a transformational approach

Although MDA defines each stage for building software from models, it does not specify any concrete technique. In this sense, in the Web applications development, little methodological support is provided to both define and apply model to model transformations. In this work, we present a strategy based on graph transformations in order to define and to automatically apply model to model transformations. This strategy has been used to automate the OOWS CIM to PIM transformation.

Context-Adaptive Coordination of Pervasive Services by Interpreting Models during Runtime†

One of the most important goals of pervasive systems is to help users in their daily life by automating their behaviour patterns. To achieve this, pervasive services must be dynamically coordinated, executed and adapted to context according to user behaviour patterns. In this work, we propose a model-driven solution to meet this challenge. We propose a task model and a context ontology to design context-adaptive coordination of services at a high level of abstraction. This design facilitates the coordination analysis at design time and is also reused at runtime. We propose a software architecture that interprets the models at runtime in order to coordinate the service execution that is required to support user behaviour patterns. This coordination is done in a context-adaptive way and decoupled from service implementation. This approach makes the models the only representation of service coordination, which facilitates the maintenance and evolution of the executed service coordination after deployment.

Transforming web requirements into navigational models: AN MDA based approach

Model Driven Architecture (MDA) is being adopted as a new development strategy. MDA is based on both the definition of models at different levels of abstraction and the application of consecutive transformations in order to obtain code from these models. However, little methodological support is provided to both define and apply model-to-model transformations. In this work, we introduce a strategy based on graph transformations that allow us to automate the derivation of the navigational model of the OOWS method from early requirements specifications, by following an MDA-based development process. In order to define and apply the graph transformations the Attributed Graph Grammar tool is used. In addition, due to the OOWS PIM-to-Code transformation capabilities, we show how this strategy allows us to obtain prototypes of web applications from early requirements specifications.

Developing e-commerce applications from task-based descriptions

In the development of E-commerce applications several decisions must be taken to provide the information, functionality and navigation that better fills to the commercial needs of an organization. These decisions define the requirements that an E-commerce application must satisfy. Although there are a significant number of proposals for modelling and developing E-commerce applications, very few of them clearly state how to elicit and represent E-commerce requirements, and how to go from the requirements specification to the Web conceptual model with a sound methodological basis. This work presents an approach to capture E-commerce application requirements by means of: (1) the identification of the tasks that users must be able to achieve and (2) the description of these tasks from the point of view of the interaction that the user requires of the web application. In addition, we show how the web conceptual model of the OOWS method can be systematically derived from a task description.

Towards the involvement of end-users within model-driven development

The models that guide the development of software systems Model-Driven Development (MDD) are usually conceived to be used by software professional developers and they are quite difficult to be understood by end-users. In this work, we propose a method that improves the involvement of end-users within MDD approaches. Furthermore, we present an example of how each step of the method is applied to involve end-users within an existing MDD approach for developing smart homes.