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Technical debt refers to decisions made during the design and development of software that postpone the resolution of technical problems or the enhancement of the software’s features to a later date. If not properly managed, technical debt can put long-term software quality and maintainability at risk. Self-admitted technical debt is defined as the addition of specific comments to source code as a result of conscious and deliberate decisions to accumulate technical debt. In this paper, we will look at the presence of self-admitted technical debt in open-source blockchain projects, which are characterized by the use of a relatively novel technology and the need to generate trust. The self-admitted technical debt was analyzed using NLP techniques for the classification of comments extracted from the source code of ten projects chosen based on capitalization and popularity. The analysis of self-admitted technical debt in blockchain projects was compared with the results of previous non-blockchain open-source project analyses. The findings show that self-admitted design technical debt outnumbers requirement technical debt in blockchain projects. The analysis discovered that some projects had a low percentage of self-admitted technical debt in the comments but a high percentage of source code files with debt. In addition, self-admitted technical debt is on average more prevalent in blockchain projects and more equally distributed than in reference Java projects.If not managed, the relatively high presence of detected technical debt in blockchain projects could represent a threat to the needed trust between the blockchain system and the users. Blockchain projects development teams could benefit from self-admitted technical debt detection for targeted technical debt management.

The evaluation websites of ICO (Initial coin offering) a way to raise funds for creating a new coin, app, or service launches, represent the main source where investors can find interesting information about their investments on one or more ICOs. In the last years many websites offered the possibility to evaluate ICOs. Among all, we chose 8 significant websites where rating, team, socials, platform, country and many other properties are shown for each ICO. These properties can be very helpful to figure out whether an ICO might be a good opportunity or a scam. Analyzing data found on ICOBench website using APIs, we found the same data for 7 other websites using the scraper. Then, we compared the gathered data in order to be able to define the quality of the evaluation websites regarding completeness and clarity of the shown information, finding several differences in rating parameters and ICO distribution. For this purpose we developed an ad-hoc scraping tool to collect in a common data structure the information shown in each website. Thanks to the data obtained with the tool we made interesting analysis, showing the differences between the ICO parameters of the different websites and defining completeness and clarity of the information.

Blockchain technologies and smart contracts are becoming mainstream research fields in computer science and researchers are continuously investigating new frontiers for new applications. Likewise, microservices are getting more and more popular in the latest years thanks to their properties, that allow teams to slice existing information systems into small and independent services that can be developed independently by different teams. A symmetric paradigm applies to smart contracts as well, which represent well defined, usually isolated, executable programs, typically implementing simple and autonomous tasks with a well defined purpose, which can be assumed as services provided by the Contract. In this work we analyze a concrete case study where the microservices architecture environment is replicated and implemented through an equivalent set of smart contracts, showing for the first time the feasibility of implementing a microservices-based system with smart contracts and how the two innovative paradigms match together. Results show that it is possible to implement a simple microservices-based system with smart contracts maintaining the same set of functionalities and results. The result could be highly beneficial in contexts such as smart voting, where not only the data integrity is fundamental but also the source code executed must be trustable. acceptedVersion

Blockchain-based crowdfunding is an emerging economic phenomenon and a state-of-the-art strategy to finance ventures. It bears similarity to conventional crowdfunding, but has its own unique characteristics. Therefore the success factors that affect the outcome of traditional crowdfunding may have a different impact on blockchain-based crowdfunding. Despite that the number of blockchain-based crowdfunding campaigns has increased drastically in the past few years, there is a lack of good understanding of what the success factors are for them in comparison to the ones for conventional crowdfunding. Such understanding is crucial for companies to design their blockchain-based fundraising initiatives properly and facilitate potential investors to seek main signals and drivers of outstanding projects. Furthermore it could help regulators and market participants to understand how the existing regulatory framework applies to blockchain-based crowdfunding. Due to specific characteristics of blockchain-based crowdfunding, regulatory frameworks may require potential re-interpretation of requirements to allow an effective application of regulations. To fill this knowledge gaps, we have reviewed a set of relevant literature on success factors for conventional and blockchain-based crowdfunding. The result of this literature review sheds light on the directions for future research and development. The contribution of our work is a better understanding of the distinctions and similarities of blockchain-based crowdfunding compared to traditional crowdfunding.

An ICO (Initial Coin Offering) is an innovative way to fund projects based on blockchain. The funding is based on the selling of tokens by means of decentralized applications called smart contracts written in Solidity, a programming language specific for Ethereum blockchain. The ICOs work in a volatile context and it is crucial that the team is capable of handling constant changes. The Agile methods, proven practices enabling to develop software in presence of changing requirements, could be a means for managing uncertainty. The main goals of this work are to understand software engineering activities related to ICOs, recognize the ICOs developed using Agile methods, and make a comparison between ICOs and Agile ICOs. In addition, we perform a deeper analysis of Agile ICOs concerning project planning, software development, and code features. Our work shows that the roles of the people involved in an ICO can be compared to the typical roles of the SCRUM methodology. The majority of Agile ICOs use tool of testing before storing smart contract on blockchain. Finally, the application of volumetric and complexity software metrics shows that the files of Agile ICOs is on average shorter and less complex than in other smart contracts.

We present an application of Blockchain technology and Smart Contracts to the management of Agile projects, using Scrum or Lean-Kanban processes. In our application the duties of the Product Owner for certifying the correctness of the outcomes are delegated to one or more Smart Contracts deployed on the Ethereum Blockchain and written in Solidity. An agreement with the Customer can also allow the Smart Contracts to automatically enable payments, to introduce penalties or grants on the basis of the outcome. Product Owner duties and work can thus be relieved allowing to allocate resources on more profitable and productive tasks. Other possibilities are examined as well.

Since 1978 several Lean Strategies have been defined and nowadays companies are increasing the adoption of them. However, there are still several practitioners that face some issues in understanding which practice is most suitable for their context and how to apply the practice in the correct way. In order to help practitioners to select which practice to adopt, in this work we provide a systematic comparison of the most common Lean Strategies based on a structured literature review. We compared the process models of the six most common Lean Strategies including: Lean Design, Lean Innovation, Lean Manufacturing, Lean Thinking, Lean SixSigma and Lean Startup.

Initial Cryptoasset Offering (ICO), also often called Initial Coin Offering or Initial Token Offering (ITO) is a new means of fundraising through blockchain technology, which allows startups to raise large amounts of funds from the crowd in an unprecedented speed. However it is not easy for ordinary investors to distinguish genuine fundraising activities through ICOs from scams. Different websites that gather and evaluate ICOs at different stages have emerged as a solution to this issue. What remains unclear is how these websites are evaluating ICOs, and consequently how reliable and credible their evaluations are. In this paper we present the first findings of an analysis of a set of 28 ICO evaluation websites, aiming at revealing the state of the practice in terms of ICO evaluation. Key information about ICOs collected by these websites are categorised, and key factors that differentiate the evaluation mechanisms employed by these evaluation websites are identified. The findings of our study could help a better understanding of what entails to properly evaluate ICOs. It is also a first step towards discovering the key success factors of ICOs.

Just a few years after its birth, Knowledge Management drew the attention of the academic world, becoming a matter of intense study as the scientific community has always felt the need to create the cooperation among its members allowing the information exchange. Many disciplines develop several standardized formalization that domain experts can use to share information as reusable knowledge. The purpose of this chapter is the study of a process to formalize knowledge by using an iterative approach mixing a top-down and bottom up analysis of a specific domain and the bottom-up analysis for the information in the object of the specific domain. Our case study analyzes the domain of descriptions and reviews of Italian wines. We start by analyzing the information collected from the Web in order to define a taxonomy able to represent the knowledge related to the above mentioned domain.

SUMMARY A software maintenance process is important for reducing maintenance effort and for improving software quality. In recent years, the Lean–Kanban approach has been widely applied in software practice including software maintenance. This approach minimizes Work-in-Progress (WIP), which is the number of items that are worked on by the team at any given time, thus improving the maintenance process. In this paper, we describe our simulation studies, which show that the Lean–Kanban approach can indeed help reduce the average time needed to complete maintenance requests. We develop a process simulator that can simulate both existing maintenance processes that do not use a WIP limit and that adopt it. We perform two case studies using real maintenance data collected from a Microsoft project and from a Chinese software firm. The main results of our study are twofold. First, we demonstrate that it is possible to effectively model and simulate, using actors and events, a maintenance process where a flow of issues is processed through a sequence of activities, correctly reproducing key statistics of real data. Second, our results confirm that the WIP-limited process could be useful to increase the efficiency of software maintenance, as reported in previous industrial practices. Copyright © 2013 John Wiley & Sons, Ltd.

SETI, the Search for ExtraTerrestrial Intelligence, is the search for radio signals emitted by alien civilizations living in the Galaxy. Narrow-band FFT-based approaches have been preferred in SETI, since their computation time only grows like N*lnN, where N is the number of time samples. On the contrary, a wide-band approach based on the Kahrunen-Lo`eve Transform (KLT) algorithm would be preferable, but it would scale like N*N. In this paper, we describe a hardware-software infrastructure based on FPGA boards and GPU-based PCs that circumvents this computation-time problem allowing for a real-time KLT.

The structure of the Web grows and changes, giving the user the chance to actively participate in its development. This study tries to link the worlds of Social Media and Semantic Web, with the aim of proposing a semantic classification of the information coming from the Web. Our approach consists in a mixed-iterative process, where top-down and bottom-up analyses of the knowledge domain which has to be represented are applied. We start from the concept of the domain knowledge base. The fundamental body of knowledge available on a domain is the knowledge valuable for knowledge users. We need to represent and manage this knowledge, to define a formalization and codification of knowledge in the domain. This kind of representation was created according to the criteria by which information, in a given domain, is structured within the net, by taking the hierarchy proposed in different sites as a reference.

Agile software development is now in its teens. It began by performing in relatively small pioneering organizations; then it gained the interest of medium-size companies, academia, and applied research institutions and laboratories; nowadays it runs in organizations of any kind, including major software and systems development companies. Because of such a wide diffusion of Agile in industry, the need for collaboration between academics and practitioners increases, in the aim of improving the body of knowledge available to help managers, system engineers, and software engineers to take their managerial/economical, and architectural/project / technical decisions. During its 15 editions, the XP conference has been a major supporter of the Agile vision of software development. Year after year, the XP conference has been supporting the improvements, observing the growth, of the Agile software development and providing evidence about the advantages that Agile development can provide. In fact, these XP editions brought together industrial practitioners and researchers in the fields of information systems and software development. They examined latest theory, practical applications and implications of agile and lean methods. XP2014, in continuity with the past editions, built a multidisciplinary platform for research and practice on various aspects of agile methods, increased interaction and collaboration between practitioners and researchers, discussed and rethought the relationships, synergies, compatibilities and incompatibilities between agile and lean practices. XP2014 committees included the Research Program Committee and the Experience Report Program Committee. This book presents the regular papers and short papers that the former, and the experience reports that the latter, respectively, accepted for presentation at XP2014. Let’s note that the acceptance process was really selective; specifically, more than 50% of the submitted papers and experience reports were rejected. This book presents chapters concerning or rethinking Agile and Lean development research topics, including: Contracting, Maturity modeling, Value-Based Software Development, Large-Scale Software Development, Methods, Metrics, Testing, Challenges and Perspectives, Software Development in Practice and Teaching at University. The experience reports come from both industry and research institutes, and their topics span from studying global architecture design approaches to investigating challenges involved when advancing software development practices. Hopefully, we reached the goal of doing our best in serving the Agile community by synthesizing the states of the art and practice and tracing its perspectives.

In recent years, we witnessed the diffusion and rise in popularity of software platforms for the User Generated Content (UGC) management, especially multimedia objects. These platforms handle a large amount of unclassified information. UGC websites (e.g. YouTube and Flickr) do not force the users to perform classification operations and metadata definitions, leaving space to a logic of free-tags (Folksonomies). We analyzed the standards used in UGC websites for the management of the multimedia contents and their metadata. We defined an ontology to represent the semantics of these multimedia contents, so that in turn the metadata classification can give an unambiguous meaning. In order to unify metadata coming from different sources we defined all rules of mapping toward a structure defined by sources such as YouTube and Flickr. The innovation is in the approach for the formalization of web semantics for multimedia content: we used standards such as Dublin Core, Exif, IPTC and in particular the Adobe XMP standard as a starting point of this domain. With the proposed approach, once can categorize and catalog all non-standard and unclassifiable information inside the ontology, using pre-made schemas.

We developed an event-driven simulator of the Kanban process a WIP limited pull system visualized by the Kanban board. WIP (work in process) represent the capacity in the activity to perform features simoultaneously. The simulator is fully object-oriented, and its design model reflects the objects of the Lean software development domain. We used this simulator to assess comparatively WIP-limited and unlimited processes. We also studied the optimum values of the working item limits in the activities, using a paradigmatic case of 4 activities and 100 work items. The cost function used is equal to the total time needed to complete the project, plus a weighted sum of the limits themselves. We performed an exhaustive search on all the admissible values of the solution, finding sensible optimal values, and a non-trivial behavior of the cost function in the optimization space.