Systematic formulation of non-functional characteristics of software

This paper presents NoFun, a notation aimed at dealing with non-functional aspects of software systems at the product level in the component programming framework. NoFun can be used to define hierarchies of non-functional attributes, which can be bound to individual software components, libraries of components or (sets of) software systems. Non-functional attributes can be defined in several ways, being possible to choose a particular definition in a concrete context. Also, NoFun allows to state the values of the attributes in component implementations, and to formulate non-functional requirements over component implementations. The notation is complemented with an algorithm able to select the best implementation of components (with respect to their non-functional characteristics) in their context of use.Peer ReviewedPostprint (published version

StarGro: Building i* metrics for agile methodologies

Requirements management is one of the cornerstone activities in software development. Agile methodologies use dedicated methods, techniques and artifacts in order to implement this activity. Remarkably, Backlog Grooming is the activity of managing and welcoming changing requirements in SCRUM. However, current industrial practices in agile development still tend to render this process in the shape of a list of statements, features and bug fixes that often leads to a blurred view of the goals of the project, the underestimation of client's needs and the decrease of the ability to respond to changes. In this paper we outline an approach that uses goal and agent oriented modelling techniques in order to fill in this "intentional" gap that current industrial approaches lack.Peer ReviewedPostprint (published version

A goal model for crowdsourced software engineering

Crowdsourced Software Engineering (CSE) is the act of undertaking any external software engineering tasks by an undefined, potentially large group of online workers in an open call format. Using an open call, CSE recruits global online labor to work on various types of software engineering tasks, such as requirements extraction, design, coding and testing. The field is rising rapidly and touches various aspects of software engineering. CSE has grown significance in both academy and industry. Despite of the enormous usage and significance of CSE, there are many open challenges reported by various researchers. In order to overcome the challenges and realizing the full potential of CSE, it is highly important to understand the concrete advantages and goals of CSE. In this paper, we present a goal model for CSE, to understand the real environment of CSE, and to explore the aspects that can somehow overcome the aforementioned challenges. The model is designed using RiSD, a method for building Strategic Dependency (SD) models in the i* notation, applied in this work using iStar2.0. This work can be considered useful for CSE stakeholders (Requesters, Workers, Platform owners and CSE organizations).Peer ReviewedPostprint (published version

Bridging the gap between design and implementation of components libraries

Object-oriented design is usually driven by three main reusability principles: step-by-step design, design for reuse and design with reuse. However, these principles are just partially applied to the subsequent object-oriented implementation, often due to efficienc y constraints, yielding to a gap between design and implementation. In this paper we provide a solution for bridging this gap for a concrete framework, the one of designing and implementing container-like component libraries, such as STL, Booc h Components, etc. Our approach is based on a new design pattern together with its corresponding implementation. The proposal enhances the same principles that drive the design process: step-by--step implementation (adding just what is needed in every step), implementation with reuse (component implementations are reused while library implementation progresses and component hierarchies grow) and implementation for reuse (intermediate component implementations can be reused in many different points o f the hierarchy). We use our approach in two different manners: for building a brand-new container-like component library, and for reengineering an existing one, Booch Components in Ada95.Postprint (published version

Adding efficient and reliable access paths to the JCF

The Java Collections Framework (JCF) is the standard Java library for representing and manipulating collections (i.e., objects that represent a group of objects, such as sets, lists, etc.). Although JCF provides adequate functionality for many purposes, it does not offer any mechanism for accessing directly the objects stored in collections apart from the standard Java references. This absence is a crucial functionality exhibited by many other widespread Java and non-Java collection libraries. In this paper, we carry out a reengineering process on the JCF to add this kind of alternative access paths, which we give the name of shortcuts. This process relies on a framework called Shortcut-Based Framework, which has been defined as library- independent. We present this framework and then we show how it may be tailored to the specific case of the JCF. The resulting JCF with shortcuts library is fully compatible with the original one (i.e., programs using the original JCF are not required to be modified), and exhibits good behaviour with respect to efficiency, reliability and internal quality. As an additional benefit of the framework, we mention that it can be applied to other collection libraries, as we have done before with an Ada95 one.Postprint (published version

Supporting process reuse in PROMENADE

Process reuse (the ability to construct new processes by assembling already built ones) and process harvesting (the ability to build generic processes that may be further reused, from existing ones) are two crucial issues in process technology. Both activities involve defining a set of mechanisms, like abstraction, adaptation, composition, etc. which are appropriate to achieve their goals. In this report, we define a general framework to process reuse and harvesting that proposes a complete set of mechanisms to deal with both activities. This general framework is particularized to the context of a process modelling language to model software processes, called PROMENADE. A definition of the identified reuse and harvesting mecha-nisms is proposed in the context of PROMENADE. Finally, two process reuse case studies which composes various reuse mechanisms are presented.Postprint (published version

Software process modelling as relationships between tasks

Systematic formulation of software process models is currently a challenging problem in software engineering. We present an approach to define models covering the phases of specification, design, implementation and testing of software systems in the component programming framework, taking into account non-functional aspects of software (efficiency, etc.), automatic reusability of implementations in systems and also prototyping techniques involving both specifications and implementations. Our proposal relies on the identification of a catalogue of tasks that appear during these phases which satisfy some relationships concerning their order of execution. A software process model can be defined as the addition of more relationships over these tasks using a simple, modular process language. We have developed also a formal definition of correctness of a software development with respect to a software process model, based on the formulation of models as graphs.Peer ReviewedPostprint (published version

Personal recommendations in requirements engineering : the OpenReq approach

[Context & motivation] Requirements Engineering (RE) is considered as one of the most critical phases in software development but still many challenges remain open. [Problem] There is a growing trend of applying recommender systems to solve open RE challenges like requirements and stakeholder discovery; however, the existent proposals focus on specific RE tasks and do not give a general coverage for the RE process. [Principal ideas/results] In this research preview, we present the OpenReq approach to the development of intelligent recommendation and decision technologies that support different phases of RE in software projects. Specifically, we present the OpenReq part for personal recommendations for stakeholders. [Contribution] OpenReq aim is to improve and speed up RE processes, especially in large and distributed systemsPeer ReviewedPostprint (author's final draft