Silvia Abrahão

A functional size measurement method for object-oriented conceptual schemas: design and evaluation issues

Functional Size Measurement (FSM) methods are intended to measure the size of software by quantifying the functional user requirements of the software. The capability to accurately quantify the size of software in an early stage of the development lifecycle is critical to software project managers for evaluating risks, developing project estimates and having early project indicators. In this paper, we present OO-Method Function Points (OOmFP), which is a new FSM method for object-oriented systems that is based on measuring conceptual schemas. OOmFP is presented following the steps of a process model for software measurement. Using this process model, we present the design of the measurement method, its application in a case study, and the analysis of different evaluation types that can be carried out to validate the method and to verify its application and results.

A systematic review of the use of requirements engineering techniques in model-driven development

Model-Driven Development (MDD) emphasizes the use of models at a higher abstraction level in the software development process and argues in favor of automation via model execution, transformation, and code generation. However, one current challenge is how to manage requirements during this process whilst simultaneously stressing the benefits of automation. This paper presents a systematic review of the current use of requirements engineering techniques in MDD processes and their actual automation level. 72 papers from the last decade have been reviewed from an initial set of 884 papers. The results show that although MDD techniques are used to a great extent in platform-independent models, platform-specific models, and at code level, at the requirements level most MDD approaches use only partially defined requirements models or even natural language. We additionally identify several research gaps such as a need for more efforts to explicitly deal with requirements traceability and the provision of better tool support.

An Object-Oriented Approach to Automate Web Applications Development

This paper presents the Object-OrientedWeb-Solutions Modeling approach (OOWS), which provides mechanisms to deal with the development of hypermedia information systems and e-commerce applications in web environments. It is proposed as an extension of an object-oriented method for automatic code generation based on conceptual models (OO-Method). The main contribution of this work is the introduction of a navigational model that is completely embedded in the process of conceptual modeling, to specify navigational features as a main part of what is conventionally specified during the conceptual modeling process. This navigational model provides abstraction primitives that allow to capture and represent navigational semantics in a precise way. We show how to put into practice the OOWS approach through a successful practical example developed within the context of e-commerce applications.

Usability Evaluation of User Interfaces Generated with a Model-Driven Architecture Tool

Model-driven architecture (MDA) has recently attracted the interest of both the research community and industry corporations. It specifies an automated process for developing interactive applications from high-level models to code generation. This approach can play a key role in the fields of software engineering (SE) and human-computer interaction (HCI). Although there are some MDA-compliant methods for developing user interfaces, none of them explicitly integrates usability engineering with user interface engineering. This chapter addresses this issue by showing how the usability of user interfaces that are generated automatically by an industrial MDA-compliant CASE tool can be assessed. The goal is to investigate whether MDA-compliant methods improve software usability through model transformations. To accomplish this, two usability evaluations were conducted in the code model (final user interface). Results showed that the usability problems identified at this level provide valuable feedback on the improvement of platform-independent models (PIM) and platform-specific models (PSM) supporting the notion of usability produced by construction.

Assessing the Effectiveness of Sequence Diagrams in the Comprehension of Functional Requirements: Results from a Family of Five Experiments

Modeling is a fundamental activity within the requirements engineering process and concerns the construction of abstract descriptions of requirements that are amenable to interpretation and validation. The choice of a modeling technique is critical whenever it is necessary to discuss the interpretation and validation of requirements. This is particularly true in the case of functional requirements and stakeholders with divergent goals and different backgrounds and experience. This paper presents the results of a family of experiments conducted with students and professionals to investigate whether the comprehension of functional requirements is influenced by the use of dynamic models that are represented by means of the UML sequence diagrams. The family contains five experiments performed in different locations and with 112 participants of different abilities and levels of experience with UML. The results show that sequence diagrams improve the comprehension of the modeled functional requirements in the case of high ability and more experienced participants.

Conceptual Modelling of Web Applications: The OOWS Approach

This chapter introduces a method that integrates navigational and presentational designs to object-oriented conceptual modelling, and also provides systematic code generation. The essential expressiveness is provided using graphical schemas that specify navigation and presentation features, and use high-level abstraction primitives. Using conceptual schemas as input, a methodology is defined to systematically take a problem space to the solution space by defining a set of correspondences between conceptual modelling abstractions and the final software components. We also provide a case study that details the application of the proposed methodology.

Early Usability Evaluation in Model Driven Architecture Environments

Due to the increasing interest in the model driven architecture (MDA) paradigm, the conceptual models have become the backbone of the software development process. So far some methods exist to develop a user interface according to a MDA-compliant method, none of them explicitly connects usability to their process activities. In this paper, we present a framework which incorporates usability as part of a MDA development process. In particular, a usability model for early evaluation is proposed. Using this model, the usability of a software system is evaluated and improved at the platform independent model (PIM) level. It focuses on the correspondences between the abstract user interface elements and the final user interface elements in a specific platform (CM). This framework has been successfully applied to an industrial MDA tool

A systematic review of quality attributes and measures for software product lines

It is widely accepted that software measures provide an appropriate mechanism for understanding, monitoring, controlling, and predicting the quality of software development projects. In software product lines (SPL), quality is even more important than in a single software product since, owing to systematic reuse, a fault or an inadequate design decision could be propagated to several products in the family. Over the last few years, a great number of quality attributes and measures for assessing the quality of SPL have been reported in literature. However, no studies summarizing the current knowledge about them exist. This paper presents a systematic literature review with the objective of identifying and interpreting all the available studies from 1996 to 2010 that present quality attributes and/or measures for SPL. These attributes and measures have been classified using a set of criteria that includes the life cycle phase in which the measures are applied; the corresponding quality characteristics; their support for specific SPL characteristics (e.g., variability, compositionality); the procedure used to validate the measures, etc. We found 165 measures related to 97 different quality attributes. The results of the review indicated that 92% of the measures evaluate attributes that are related to maintainability. In addition, 67% of the measures are used during the design phase of Domain Engineering, and 56% are applied to evaluate the product line architecture. However, only 25% of them have been empirically validated. In conclusion, the results provide a global vision of the state of the research within this area in order to help researchers in detecting weaknesses, directing research efforts, and identifying new research lines. In particular, there is a need for new measures with which to evaluate both the quality of the artifacts produced during the entire SPL life cycle and other quality characteristics. There is also a need for more validation (both theoretical and empirical) of existing measures. In addition, our results may be useful as a reference guide for practitioners to assist them in the selection or the adaptation of existing measures for evaluating their software product lines.

Defining and validating metrics for navigational models

Nowadays, several approaches for developing Web applications have been proposed in the literature. Most of them extend existing object-oriented conceptual modeling methods, incorporating new constructors in order to model the navigational structure and the content of Web applications. Such new constructors are commonly represented in a navigational model. While navigational models constitute the backbone of Web application design, their quality has a great impact on the quality of the final product, which is actually implemented and delivered. We discuss a set of metrics for navigational models that has been proposed for analyzing the quality of Web applications in terms of size and structural complexity. These metrics were defined and validated using a formal framework (DISTANCE) for software measure construction that satisfies the measurement needs of empirical software engineering research. Some experimental studies have shown that complexity affects the ability to understand and maintain conceptual models. In order to prove this, we also made a controlled experiment to observe how the proposed metrics can be used as early maintainability indicators.

Measuring the functional size of web applications

Today, more and more Web sites and Applications (WebApps) are becoming mission-critical systems. Measures of functional size are a prerequisite to successful quantitative management of software projects. However, the nature of the web has recently imposed new and challenging characteristics, which are not supported by the existing estimation metric and models. In order to avoid the Web crisis, we urge the use of web engineering approaches for developing and estimating web projects in a systematic way. To achieve this goal, we present a novel size metric for accurately measuring the functional size of web applications early in the development life cycle. The main contribution of this work is the introduction of a measurement process that is embedded in the conceptual modelling phase of a model-driven approach for developing web applications. The results obtained from our experiments with this approach are outlined in this work.