Hernan Astudillo
Universidad Técnica Federico Santa María, Informática, Faculty Member
- Digital Humanities, Web 2.0, Digital Libraries, Social Computing, Wikis, History, and 12 moreDigital History, Humanities Visualization, Intangible cultural heritage, Medieval Studies, Bactria, Hellenism, Indo-Greeks, Late Antique and Byzantine Studies, Andean Archaeology, Ottoman History, Ancient Near East, Hellenistic Babylonia, Persianate Culture in South Asia, and Medieval frontiersedit
Large software systems are designed to satisfy or accommodate many requirements; architectural patterns are a well-known technique to reuse design knowledge. However, requested quality attributes (QA) may be inconsistent at times; e.g.,... more
Large software systems are designed to satisfy or accommodate many requirements; architectural patterns are a well-known technique to reuse design knowledge. However, requested quality attributes (QA) may be inconsistent at times; e.g., high security typically hampers performance and scalability. Thus, a key concern of systems architects is understanding trade-offs among alternative solutions; e.g., a pattern may favor performance at the expense of scalability or security, another may privilege scalability, and yet another may push security. This article argues that the usual organization of individual patterns in topic-related pattern languages is not too helpful to identify trade-offs, and proposes to borrow a taxonomic principle of architectural tactics, organizing the patterns for each QA into “moments”. This enables architects to use simple tradeoff highlighting techniques to understand trade-offs in complex systems. The approach was used in the systematic design of a SCADA-to-ERP secure bridge, where moment-oriented pattern taxonomies for availability, confidentiality, and performance were used. This approach offers the promise of enabling the trade-offenabled, pattern-driven design of large systems by supporting the systematic exploration of trade-offs among patterns for specific QA’s.
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The Electronic Health Record (EHR) is a digital document that stores sensitive patient information. In this regard, there are novel techniques and methods for satisfying security in EHR in specific domains (such as authentication,... more
The Electronic Health Record (EHR) is a digital document that stores sensitive patient information. In this regard, there are novel techniques and methods for satisfying security in EHR in specific domains (such as authentication, networking, cryptography, among others). Nevertheless, there is not enough evidence on quality instruments composed of cross-cutting security metrics obtained from academic as well as grey literature. This article proposes a quality instrument that measures the satisfaction degree of security in EHRs. The instrument is composed of five security approaches and nineteen security metrics collected and characterized from the academic and grey literature. We evaluated the effectiveness of the quality instrument in a case study with 20 healthcare actors in Chile. The results suggest that the metric is quite effective, but it depends on the degree of security training of the clinical staff. The findings of this study support the idea that our quality instrument can be considered as a starting point to evaluate the quality of EHRs.
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The software engineering literature describes several decision-making techniques for architectural design. However, the impact of the experience of those who use these techniques on their efficacy has been little explored. This article... more
The software engineering literature describes several decision-making techniques for architectural design. However, the impact of the experience of those who use these techniques on their efficacy has been little explored. This article addresses this research gap through an experimental study to evaluate the impact of experience of software architecture decision-making team members on the efficacy of TaSPeR (Tactics Selection Poker), a software architecture tactics selection technique based on Planning Poker. A set of 24 IT professional developers was divided into two “expert” teams and two “novice” teams (of six people each); each team had to solve two scenarios, one using TaSPeR and one using an ad-hoc technique; the scenarios were crossed to mitigate possible learning effects. The study compared the effectiveness of teams in terms of precision, recall, and accuracy (of selected tactics versus a ground truth); accuracy was found best. Initial results suggest that TaSPeR improves the accuracy of novice teams but hurts the accuracy of expert teams. This result is quite unexpected and begs replication with even larger populations of IT professionals (no easy task). If the results are confirmed, the question that will rise is: if consensus techniques are so good to estimate, why would they hurt design decision-making by expert teams?
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Software process improvement (SPI) initiatives are based upon an appropriate assessment of the actual state or maturity of processes and a concrete model to guide engineers in the next steps to move from the actual state to an improved... more
Software process improvement (SPI) initiatives are based upon an appropriate assessment of the actual state or maturity of processes and a concrete model to guide engineers in the next steps to move from the actual state to an improved one. In the context of an SPI initiative at the Chilean National Customs Service, we used the SEMAT Kernel to assess software processes and to guide the implementation of practices for their improvement. We present in this paper our experience using the SEMAT Kernel. We also present a description of several lessons learned in this experience.
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Architectural Technical Debt (ATD) is a metaphor used to describe consciously decisions taken by software architects to accomplish short-term goals but possibly negatively affecting the long-term health of the system. However,... more
Architectural Technical Debt (ATD) is a metaphor used to describe consciously decisions taken by software architects to accomplish short-term goals but possibly negatively affecting the long-term health of the system. However, difficulties arise when repayment strategies are defined because software architects need to be aware of the consequences of these strategies over others decisions in the software architecture. This article proposes REBEL, a semi-automated model-driven approach that exploits natural language processing, machine learning and model checking techniques on heterogeneous project artifacts to build a model that allows to locate and visualize the impact produced by the consciously injected ATD and its repayment strategy on the other architectural decisions. The technique is illustrated with a data analytics project in Colombia where software architects are unaware of the consequences of the repayment strategies. This proposal seeks to support teams of architects to make explicit the current and future impact of the ATD injected as a result of decisions taken, focusing on the architectural level rather than code level.
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The UNESCO convention on Intangible Cultural Heritage (ICH) requires countries to document their oral traditions, performing arts, traditional festivities, and so forth. Several institutions gather ICH, traditionally by hand, and record... more
The UNESCO convention on Intangible Cultural Heritage (ICH) requires countries to document their oral traditions, performing arts, traditional festivities, and so forth. Several institutions gather ICH, traditionally by hand, and record and disseminate it through conventional information systems (static knowledge in relational databases, RDB). Two difficulties are that (1) review/refinement of their underlying database schemata by domain experts becomes disruptive, and (2) contribution from community, non-expert users becomes hard, even impossible. This article presents an interactive tool that implements a recent technique to perform Knowledge Discovery in Databases (KDD) guided by Formal Concept Analysis (FCA). The tool takes an RDB schema (in SQL), translates it into a formal context and later in a concept lattice using the CORON platform, allows domain experts to manipulate it and produces a formal ontology (in RDFS). Later, the ontology can be used to instantiate a semantic wik...
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Mercado Pablico is a ChileCompra's platform for tenders, an environment where Chilean companies offer and demand goods and services of all kinds. The main aim of this platform is to make more efficient and transparent the contracting... more
Mercado Pablico is a ChileCompra's platform for tenders, an environment where Chilean companies offer and demand goods and services of all kinds. The main aim of this platform is to make more efficient and transparent the contracting processes. Nowadays, tenders asking more than one good and/or service are answered separately. Thus, after receiving the offers from the sellers, the buyer must select for each part of the tender the best offer. Unfortunately, this is an inefficient and non optimal process. On the one hand, buyers spend much time in building a joint contract where not necessarily they obtained the best deal and on the other hand, small providers are less likely to be selected (if they apply) when competing with bigger providers or alliances of them (which already offer most products and typically at better prices). To address these issues, we presented VirtualMarket, a multi-agent platform, which extends the ChileCompra's platform representing providers as software agents (with willingness to cooperate), which, through the creation of alliances, are capable of naturally identifying associativity opportunities, when tenders are published, and negotiate preagreements which make them more competitive. In this ongoing work, we propose to use a slightly modified version of the Zeuthen Strategy in order to support providers agents during the negotiation of the terms of the alliance formation without revealing their utility functions. Our preliminary results about the feasibility and performance of our proposal are encouraging.
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In virtual markets based on multi-agent systems, clients and providers delegate the responsibility of buying or selling a product or service to software agents. In this sense, decentralized negotiation strategies in multi-agent systems... more
In virtual markets based on multi-agent systems, clients and providers delegate the responsibility of buying or selling a product or service to software agents. In this sense, decentralized negotiation strategies in multi-agent systems are the key to allow that agents to reach agreements. However, in environments where there is not any mediator, to reach consensus is not warranted. In this work, we propose a decentralized strategy of negotiation in order to two or more agents may negotiate as a group at the same time several characteristics of several products. We apply this proposal in a virtual market simulating ChileCompra, where provider agents generate coalitions to satisfy tenders requesting several products or services.
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Issue 2 of volume 18 of the CLEI Electronic Journal presents a selection of the best papers from the XL Latin American Computing Conference (CLEI 2014).
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Microservice-based systems promote agility and rapid business development. Some features, such as fast time-to-market, scalability and optimal response times, have encouraged stakeholders to get more involved in the development and... more
Microservice-based systems promote agility and rapid business development. Some features, such as fast time-to-market, scalability and optimal response times, have encouraged stakeholders to get more involved in the development and implementation of microservices architectures in order to translate their business vision into the implementation of the architecture. Although some techniques allow the inclusion of the stakeholders' perspective in the design of microservice architectures, few proposals consider such perspectives in the selection and evaluation of technologies that implement microservice architectures. Indeed, the qualities that characterize microservice-based systems strongly depend on the suitable selection of technologies, such as application frameworks and platforms. This article proposes a collaborative technique that includes stakeholders and software architects in the selection and evaluation of application frameworks and platforms to implement microservice-based systems. We evaluated the technique in an industrial case of design and implementation of an Ambient-Assisted Living (AAL) system, which combines microservice architecture and Internet-of-Medical-Things (IoMT) sensors. The case results indicate that the proposed technique supported stakeholders in the pragmatic evaluation of alternative technological solutions. Additionally, it allowed the implementation of an AAL system that satisfies the quality specifications of stakeholders and end-users. This initial study suggests that actively including stakeholders in the implementation of microservice-based systems allows architects to make design decisions that better consider stakeholders viewpoints as well as managing their expectations.
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Several governmental and non-governmental organizations (NGOs), motivated by the UNESCO have undertaken the task of docu- menting the intangible cultural heritage of their communities. However, this has proven to be a dicult task. In this... more
Several governmental and non-governmental organizations (NGOs), motivated by the UNESCO have undertaken the task of docu- menting the intangible cultural heritage of their communities. However, this has proven to be a dicult task. In this work we present a conceptual knowledge discovery in databases (CKDD) approach to aid a particular organization in this task (which has already started). Because of the dy- namism of the cultural heritage domain, the design of the database used to store the documentation data has become obsolete. We propose to redesign the database (actually, its schema) to unveil independent mod- ules of information collaboratively created by dierent domain experts. Finally, we present a straightforward method to convert the redesigned data schema into an ontological model which can be used for integration and publication purposes.
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Microservices are an emerging trend for development of service-oriented software. This approach proposes to build each application as a collection of small services running on separate process and inter-communicating with lightweight... more
Microservices are an emerging trend for development of service-oriented software. This approach proposes to build each application as a collection of small services running on separate process and inter-communicating with lightweight mechanisms. Systematic development of microservices is hampered by the lack of a catalog of emerging recurrent architectural solutions (architectural patterns) and design decisions (architectural tactics). This article describes a systematic review of academic and industrial literature regarding architectural patterns and architectural tactics for microservices. The review yield 44 architectural patterns in academic sources and 74 in industrial ones, as well as a few architectural tactics originally proposed to address related problems. Most architectural patterns and tactics are associated to one of just five quality attributes: scalability, flexibility, testability, performance, and elasticity. Also, most microservices in academic (but not industrial) literature are related to DevOps and IoT. The findings lead to propose a new taxonomy of microservice architectural patterns.
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System-of-Systems (SoS) are composed by heterogeneous constituent systems that are autonomous, independently managed and operated, and geographically distributed. Architectural evaluation is a key activity of all systems design,... more
System-of-Systems (SoS) are composed by heterogeneous constituent systems that are autonomous, independently managed and operated, and geographically distributed. Architectural evaluation is a key activity of all systems design, construction and operation; unfortunately, the interrelationships among SoS constituent systems and quality attributes (QA) make hard to evaluate SoS. Several evaluation techniques have been proposed, but this corpus of knowledge has not yet been organized for easy access. This article describes the design, execution and results of a Systematic Literature Mapping (SLM) of architectural evaluation proposals, focusing on the QA's they address and the techniques they use. The SLM yield 1675 articles, of which 22 were selected for detailed analysis; most of them take a quantitative perspective (82\%) and the rest are hybrid quantitative/qualitative (18\%); most proposals offer no empirical validation at all (64\%); and the most addressed QA's are perform...
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Page 1. CONTEXTA/SR: A multi-institutional semantic integration platform Hernán Astudillo, Universidad Técnica Federico Santa María, Chile Pablo Inostroza, Universidad Técnica Federico Santa María, Chile Claudia López, Universidad Técnica... more
Page 1. CONTEXTA/SR: A multi-institutional semantic integration platform Hernán Astudillo, Universidad Técnica Federico Santa María, Chile Pablo Inostroza, Universidad Técnica Federico Santa María, Chile Claudia López, Universidad Técnica Federico Santa María, Chile ...
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Microservice-based systems promote agility and rapid business development. Some features, such as fast time-to-market, scalability and optimal response times, have encouraged stakeholders to get more involved in the development and... more
Microservice-based systems promote agility and rapid business development. Some features, such as fast time-to-market, scalability and optimal response times, have encouraged stakeholders to get more involved in the development and implementation of microservices architectures in order to translate their business vision into the implementation of the architecture. Although some techniques allow the inclusion of the stakeholders’ perspective in the design of microservice architectures, few proposals consider such perspectives in the selection and evaluation of technologies that implement microservice architectures. Indeed, the qualities that characterize microservice-based systems strongly depend on the suitable selection of technologies, such as application frameworks and platforms. This article proposes a collaborative technique that includes stakeholders and software architects in the selection and evaluation of application frameworks and platforms to implement microservice-based ...
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The open data movement is developing and has gained worldwide political relevance, resulting in a proliferation of proposals that assess the progress of open governance initiatives (OGD) in different countries. The evaluation of OGD is a... more
The open data movement is developing and has gained worldwide political relevance, resulting in a proliferation of proposals that assess the progress of open governance initiatives (OGD) in different countries. The evaluation of OGD is a subject that has been studied recently. In this study, we present a systematic mapping study to show the scopes, instrument, methods and political, technical and organizational dimensions that assess the OGD. The analysis reviewed studies published in SCOPUS between 2009 and 2018. We found that the scope of the 30 studies focuses on the evaluation of the implementation. Similarly, the main type of evaluation is the application of the initiatives, through Frameworks and indicators, in the political and technical dimensions. The above shows that it is possible to approach the evaluation of the preparation of the OGD as future work, as an instrument that supports public entities in identifying capabilities to implement an OGD program.
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Microservices is an architectural style that conceives systems as a modular, costumer, independent and scalable suite of services; it offers several advantages but its growing popularity has given rise to security challenges. Building... more
Microservices is an architectural style that conceives systems as a modular, costumer, independent and scalable suite of services; it offers several advantages but its growing popularity has given rise to security challenges. Building secure systems is greatly helped by deploying existing security mechanisms, but current literature does not guide developers about which mechanisms are actually used by developers of microservicesbased systems. This article describes the design and results of a systematic mapping study to identify the security mechanisms used in microservices-based systems described in the literature. The study yielded 321 articles, of which 26 are primary studies. Key findings are that (i) the studies mention 18 security mechanisms; (ii) the most mentioned security mechanisms are authentication, authorization and credentials; and (iii) almost 2/3 of security mechanisms focus on stopping or mitigating attacks, but none on recovering from them. Additionally, it emerges that experiments and case studies are the most used empirical strategies in microservices security research. The clear identification of most-used security solutions will facilitate the reuse of existing architectural knowledge to address security problems in microservices-based systems.
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Software architecture teaching is particularly hard for undergrad students, as the typically do not have work experience with medium or large software systems that have competing stakeholders. In particular, current software engineering... more
Software architecture teaching is particularly hard for undergrad students, as the typically do not have work experience with medium or large software systems that have competing stakeholders. In particular, current software engineering education approaches do not seem useful to teach a method like ATAM (Architecture Trade-off Analysis Method), designed for evaluation of architectural designs by competing stakeholders. This article presents a role playing game (RPG) to support teaching of ATAM to graduate informatics students, in classroom or distance learning by simulating stakeholders interaction. A case study was developed based on the Chilean National System of Tsunami Alarms (SNAM); the material includes case description and an initial proposal for architecture and utility tree, and to enable role-playing, also includes stakeholders' roles and competing goals,. Students assume some stakeholder role, prioritize and examine quality attributes, negotiate priority and difficulty of scenarios, and agree on a final architecture. The system has been piloted, and will be deployed to a graduate software architecture class in mid-July. Role playing games for software engineering education allow to exercise technically-based negotiation skills, and empirical studies like this one will gather applicability and usefulness information for its nuanced application to future cohorts.
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Abstract???E-government initiatives are being carried out by countries all around the world, to provide better services to citizens and business. Chile is not an exception in this trend and its e-government implementation strategy is... more
Abstract???E-government initiatives are being carried out by countries all around the world, to provide better services to citizens and business. Chile is not an exception in this trend and its e-government implementation strategy is considering international best practices. This ...
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Background Microservices are an architectural approach of growing use, and the optimal granularity of a microservice directly affects the application’s quality attributes and usage of computational resources. Determining microservice... more
Background Microservices are an architectural approach of growing use, and the optimal granularity of a microservice directly affects the application’s quality attributes and usage of computational resources. Determining microservice granularity is an open research topic. Methodology We conducted a systematic literature review to analyze literature that addresses the definition of microservice granularity. We searched in IEEE Xplore, ACM Digital Library and Scopus. The research questions were: Which approaches have been proposed to define microservice granularity and determine the microservices’ size? Which metrics are used to evaluate microservice granularity? Which quality attributes are addressed when researching microservice granularity? Results We found 326 papers and selected 29 after applying inclusion and exclusion criteria. The quality attributes most often addressed are runtime properties (e.g., scalability and performance), not development properties (e.g., maintainabilit...
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MASPEGHI 2004 is the third edition of the MASPEGHI workshop. This year the organizers of both the ECOOP 2002 Inheritance Workshop and MASPEGHI 2003 came together to enlarge the scope of the workshop and to address new challenges. We... more
MASPEGHI 2004 is the third edition of the MASPEGHI workshop. This year the organizers of both the ECOOP 2002 Inheritance Workshop and MASPEGHI 2003 came together to enlarge the scope of the workshop and to address new challenges. We succeeded in gathering a diverse group of researchers and practitioners interested in mechanisms for managing specialization and generalization of programming language