A Longitudinal Study of Identifying and Paying Down Architectural Debt

Architectural debt is a form of technical debt that derives from the gap between the architectural design of the system as it "should be" compared to "as it is". We measured architecture debt in two ways: 1) in terms of system-wide coupling measures, and 2) in terms of the number and severity of architectural flaws. In recent work it was shown that the amount of architectural debt has a huge impact on software maintainability and evolution. Consequently, detecting and reducing the debt is expected to make software more amenable to change. This paper reports on a longitudinal study of a healthcare communications product created by Brightsquid Secure Communications Corp. This start-up company is facing the typical trade-off problem of desiring responsiveness to change requests, but wanting to avoid the ever-increasing effort that the accumulation of quick-and-dirty changes eventually incurs. In the first stage of the study, we analyzed the status of the "before" system, which indicated the impacts of change requests. This initial study motivated a more in-depth analysis of architectural debt. The results of this analysis were used to motivate a comprehensive refactoring of the software system. The third phase of the study was a follow-on architectural debt analysis which quantified the improvements made. Using this quantitative evidence, augmented by qualitative evidence gathered from in-depth interviews with Brightsquid's architects, we present lessons learned about the costs and benefits of paying down architecture debt in practice.Comment: Submitted to ICSE-SEIP 201

Impact analysis of the CAP reform on main agricultural commodities

End of project reportThis study has been carried out for the European Commission's Joint Research Centre to analyze agricultural policies at Member State, EU15 and EU25 levels as well as for Bulgaria and Romania. The modelling tool allows for projections and policy analysis (up to a 10 year horizon) for the enlarged EU.This study has been carried out for the European Commission's Joint Research Centre, under Contract no 150267-2005-FIED-N

Sustainable car life cycle design, taking inspiration from natural systems and thermodynamics

This paper exposes the search for a tool and method, which from a systems approach, adopts the rules and logic that govern our physical context (biosphere) in order to provide guidelines that the car industry could use to achieve an ideal state for ecological, economical and social sustainability

Universal Resource Lifecycle Management

This paper presents a model and a tool that allows Web users to define, execute, and manage lifecycles for any artifact available on the Web. In the paper we show the need for lifecycle management of Web artifacts, and we show in particular why it is important that non-programmers are also able to do this. We then discuss why current models do not allow this, and we present a model and a system implementation that achieves lifecycle management for any URI-identifiable and accessible object. The most challenging parts of the work lie in the definition of a simple but universal model and system (and in particular in allowing universality and simplicity to coexist) and in the ability to hide from the lifecycle modeler the complexity intrinsic in having to access and manage a variety of resources, which differ in nature, in the operations that are allowed on them, and in the protocols and data formats required to access them

Single Value Devices

We live in a world of continuous information overflow, but the quality of information and communication is suffering. Single value devices contribute to the information and communication quality by fo- cussing on one explicit, relevant piece of information. The information is decoupled from a computer and represented in an object, integrates into daily life. However, most existing single value devices come from conceptual experiments or art and exist only as prototypes. In order to get to mature products and to design meaningful, effective and work- ing objects, an integral perspective on the design choices is necessary. Our contribution is a critical exploration of the design space of single value devices. In a survey we give an overview of existing examples. The characterizing design criteria for single value devices are elaborated in a taxonomy. Finally, we discuss several design choices that are specifically important for moving from prototypes to commercializable products

Global state, local decisions: Decentralized NFV for ISPs via enhanced SDN

The network functions virtualization paradigm is rapidly gaining interest among Internet service providers. However, the transition to this paradigm on ISP networks comes with a unique set of challenges: legacy equipment already in place, heterogeneous traffic from multiple clients, and very large scalability requirements. In this article we thoroughly analyze such challenges and discuss NFV design guidelines that address them efficiently. Particularly, we show that a decentralization of NFV control while maintaining global state improves scalability, offers better per-flow decisions and simplifies the implementation of virtual network functions. Building on top of such principles, we propose a partially decentralized NFV architecture enabled via an enhanced software-defined networking infrastructure. We also perform a qualitative analysis of the architecture to identify advantages and challenges. Finally, we determine the bottleneck component, based on the qualitative analysis, which we implement and benchmark in order to assess the feasibility of the architecture.Peer ReviewedPostprint (author's final draft

Integrating Thermodynamics and Biology for Sustainable Product Lifecycle Design

The linkage between raw resources consumption and economic growth through product manufacture and disposal is creating an untenable pressure on the planet’s natural systems; therefore understanding and embracing the mechanics of the biology and physics of our context could lead to novel approaches in the design of human-built systems/products. Designers are, by active association, responsible for that pressure and much of the impact can be traced back to the early stages of the design process. For designers and engineers the main constraint is accessibility to knowledge of multiple and complex factors in easily digestible form when starting a project. Added to this is the possibility to transcend the realm of products and explore creative solutions throughout the entire life cycle, giving designers the opportunity to propose entire new business models and systems. This paper exposes the search for an intuitive soft modeling tool that considers some of these factors and inspires the innovation of business and systems innovation from a biophysical perspective. The aim of this tool is to enable the exploration of these factors in a playful intuitive way and relate these outcomes to the design of a business model operating within the principles of trophic levels. The first key question to the development of this approach has been: how does it work in nature? Organisms search for their food in other organisms and at the same time are the food of others; biomass and energy are transferred from one level to another, losses occur, higher qualities of energy are created and all is maintained in continuous cycles. The linear human production of goods can be rethought by taking into account this basic principle of thermodynamics and although this is not a technological problem, the relevant constrains need to be integrated for this approach to be feasible. These are from an economics origin: how to achieve a healthy business from a non-linear process? It is proposed that an analogy between natural and human systems: autotrophs = manufacturing, heterotrophs = distributors and consumers, their concentration and size, their possible combinations and their eventual business interpretations, is referred to as Trophic Economics. The envisioned tool will combine the exploration of the complex factors involved in the lifecycle of a product with the suggested Trophic Economics models. The outcome could be sketches of the possible boundaries and structures of new business and products, to be resolved later on the drawing board. In order to measure and keep track of the most relevant decisions, a designer must embrace tools like emergy accounting, MIPS and MI (Wuppertal Institute, 2002) used in related combination, plus indexes of CO2 emissions and relevant economic, social-demographic and ecosystems information about the countries involved in any give proposition of manufacture and use

Towards a flexible open-source software library for multi-layered scholarly textual studies: An Arabic case study dealing with semi-automatic language processing

This paper presents both the general model and a case study of the Computational and Collaborative Philology Library (CoPhiLib), an ongoing initiative underway at the Institute for Computational Linguistics (ILC) of the National Research Council (CNR), Pisa, Italy. The library, designed and organized as a reusable, abstract and open-source software component, aims at solving the needs of multi-lingual and cross-lingual analysis by exposing common Application Programming Interfaces (APIs). The core modules, coded by the Java programming language, constitute the groundwork of a Web platform designed to deal with textual scholarly needs. The Web application, implemented according to the Java Enterprise specifications, focuses on multi-layered analysis for the study of literary documents and related multimedia sources. This ambitious challenge seeks to obtain the management of textual resources, on the one hand by abstracting from current language, on the other hand by decoupling from the specific requirements of single projects. This goal is achieved thanks to methodologies declared by the 'agile process', and by putting into effect suitable use case modeling, design patterns, and component-based architectures. The reusability and flexibility of the system have been tested on an Arabic case study: the system allows users to choose the morphological engine (such as AraMorph or Al-Khalil), along with linguistic granularity (i.e. with or without declension). Finally, the application enables the construction of annotated resources for further statistical engines (training set). © 2014 IEEE

Knowledge modelling for integrating semantic web services in e-government applications

Service integration and domain interoperability are the basic requirements in the development of current service-oriented e-Government applications. Semantic Web and, in particular, Semantic Web Service (SWS) technology aim to address these issues. However, the integration between e-Government applications and SWS is not an easy task. We argue that a more complex semantic layer needs to be modeled. The aim of our work is to provide an ontological framework that maps such a semantic layer. In this paper, we describe our approach for creating a project-independent and reusable model, and provide a case study that demonstrates its applicability