49 documents, page 1 of 3
2016 Conference object Unknown

Empowering requirements elicitation interviews with vocal and biofeedback analysis
Ferrari A., Spoletini P., Brock C., Shahwar R.
Interviews with stakeholders are the most commonly used elicitation technique, as they are considered one of the most effective ways to transfer knowledge between requirements analysts and customers. During these interviews, ambiguity is a major obstacle for knowledge transfer, as it can lead to incorrectly understood needs and domain aspects and may ultimately result in poorly defined requirements. To address this issue, previous work focused on how ambiguity is perceived on the analyst side, i.e., when the analyst perceives an expression of the customer as ambiguous. However, this work did not consider how ambiguity can affect customers, i.e., when questions from the analyst are perceived as ambiguous. Since customers are not in general trained to cope with ambiguity, it is important to provide analysts with techniques that can help them to identify these situations. To support the analysts in this task, we propose to explore the relation between a perceived ambiguity on the customer side, and changes in the voice and bio parameters of that customer. To realize our idea, we plan to (1) study how changes in the voice and bio parameters can be correlated to the levels of stress, confusion, and uncertainty of an interviewee and, ultimately, to ambiguity and (2) investigate the application of modern voice analyzers and wristbands in the context of customer-analyst interviews. To show the feasibility of the idea, in this paper we present the result of our first step in this direction: an overview of different voice analyzers and wristbands that can collect bio parameters and their application in similar contexts. Moreover, we propose a plan to carry our research out.Source: 2016 IEEE 24th International Requirements Engineering Conference, pp. 371–376, Beijing, China, 12-16 September 2016
DOI: 10.1109/RE.2016.56

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2011 Report Unknown

CBTC preliminary report
Ferrari, Alessio
CBTC are modern railway signaling systems used in urban railway lines for light rail (e.g., tranvia), heavy rail (e.g., metro) and APM (Automated People Mover, e.g., Airport metros). Sometimes, they can be deployed also on commuter lines (rails going to suburban areas, e.g., S-Bhan). This document summarizes the main features that a generic CBTC shall support, based on the current IEEE standards and on the currently analyzed implementations

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2011 Report Unknown

Evaluation of the IBM rhapsody tool for modeling automatic train protection (ATP) systems: the restrictive signal confirmation (RSC) button
Ferrari Alessio, Illiashenko Oleg, Parfenov Sergii
The current document reports the evaluation of the IBM Rational Rhapsody tool for the modeling of Automatic Train Protection (ATP) systems software. The focus of the activity is on the Restrictive Signal Confirmation (RSC) button, a typical control component that, through not used in every ATP system, is considered a good representative of the expected functionality of an ATP software.

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2015 Conference object Open Access OPEN

Automated service selection using natural language processing
Bano M., Ferrari A., Zowghi D., Gervasi V., Gnesi S.
With the huge number of services that are available online, requirements analysts face a paradox of choice (i.e., choice overload) when they have to select the most suitable service that satisfies a set of customer requirements. Both service descriptions and requirements are often expressed in natural language (NL), and natural language pro- cessing (NLP) tools that can match requirements and service descrip- tions, while filtering out irrelevant options, might alleviate the problem of choice overload faced by analysts. In this paper, we propose a NLP approach based on Knowledge Graphs that automates the process of service selection by ranking the service descriptions depending on their NL similarity with the requirements. To evaluate the approach, we have performed an experiment with 28 customer requirements and 91 service descriptions, previously ranked by a human assessor. We selected the top- 15 services, which were ranked with the proposed approach, and found 53% similar results with respect to top-15 services of the manual ranking. The same task, performed with the traditional cosine similarity ranking, produces only 13% similar results. The outcomes of our experiment are promising, and new insights have also emerged for further improvement of the proposed technique.Source: APRES 2015 - Requirements Engineering in the Big Data Era. Second Asia Pacific Symposium, pp. 3–17, Wuhan, China, 18-20 October 2015
DOI: 10.1007/978-3-662-48634-4_1

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2012 Conference object Open Access OPEN

Product line engineering applied to CBTC systems development.
Ferrari A., Spagnolo G. O., Martelli G., Menabeni S.
Communications-based Train Control (CBTC) systems are the new frontier of automated train control and operation. Currently developed CBTC platforms are actually very complex systems including several functionalities, and every installed system, developed by a different company, varies in extent, scope, number, and even names of the implemented functionalities. International standards have emerged, but they remain at a quite abstract level, mostly setting terminology. This paper reports intermediate results in an effort aimed at defining a global model of CBTC, by mixing semi-formal modelling and product line engineering. The effort has been based on an in-depth market analysis, not limiting to particular aspects but considering as far as possible the whole picture. The adopted methodology is discussed and a preliminary model is presented.Source: Leveraging Applications of Formal Methods, Verification and Validation. Applications and Case Studies. 5th International Symposium., pp. 216–229, Heraclion, Crete, 15-18 October 2012
DOI: 10.1007/978-3-642-34032-1_22

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2014 Conference object Open Access OPEN

Context transformations for goal models
Spoletini P., Ferrari A., Gnesi S.
This paper proposes a technique to support the requirements engineer in transforming existing models into new models to address the customer's needs. In particular, we identify a set of possible categories of context change that indicate in which direction the original model needs to evolve. Furthermore, we associate a transformation to each category, and we formalise it in terms of graph grammars. Our results are a generalisation of an experimental evaluation based on 10 models retrieved from the literature and 25 scenarios of context change. This work represents a step forward in the formalisation of requirements models since it provides the foundations of a tool to support the automatic transformation of models, and employs graph grammars to provide a formal layer to the approach.Source: MoDRE 2014 - IEEE 4th International Model-Driven Requirements Engineering Workshop, pp. 17–26, Karlskrona, Sweden, 25 August 2014
DOI: 10.1109/MoDRE.2014.6890822
Project(s): LEARN PAD via OpenAIRE

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2016 Article Restricted

Ambiguity and tacit knowledge in requirements elicitation interviews
Ferrari A., Spoletini P., Gnesi S.
Interviews are the most common and effective means to perform requirements elicitation and support knowledge transfer between a customer and a requirements analyst. Ambiguity in communication is often perceived as a major obstacle for knowledge transfer, which could lead to unclear and incomplete requirements documents. In this paper, we analyze the role of ambiguity in requirements elicitation interviews, when requirements are still tacit ideas to be surfaced. To study the phenomenon, we performed a set of 34 customer-analyst interviews. This experience was used as a baseline to define a framework to categorize ambiguity. The framework presents the notion of ambiguity as a class of four main sub-phenomena, namely unclarity, multiple understanding, incorrect disambiguation and correct disambiguation. We present examples of ambiguities from our interviews to illustrate the different categories, and we highlight the pragmatic components that determine the occurrence of ambiguity. Along the study, we discovered a peculiar relation between ambiguity and tacit knowledge in interviews. Tacit knowledge is the knowledge that a customer has but does not pass to the analyst for any reason. From our experience, we have discovered that, rather than an obstacle, the occurrence of an ambiguity is often a resource for discovering tacit knowledge. Again, examples are presented from our interviews to support this vision.Source: Requirements engineering (Lond., Print) (2016). doi:10.1007/s00766-016-0249-3
DOI: 10.1007/s00766-016-0249-3
Project(s): LEARN PAD via OpenAIRE

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2016 Conference object Open Access OPEN

Ensuring action: identifying unclear actor specifications in textual business process descriptions
Sanne U., Witschel H. F., Ferrari A., Gnesi S.
In many organisations, business process (BP) descriptions are available in the form of written procedures, or operational manuals. These documents are expressed in informal natural language, which is inherently open to different interpretations. Hence, the content of these documents might be incorrectly interpreted by those who have to put the process into practice. It is therefore important to identify language defects in written BP descriptions, to ensure that BPs are properly carried out. Among the potential defects, one of the most relevant for BPs is the absence of clear actors in action-related sentences. Indeed, an unclear actor might lead to a missing responsibility, and, in turn, to activities that are never performed. This paper aims at identifying unclear actors in BP descriptions expressed in natural language. To this end, we define an algorithm named ABIDE, which leverages rule-based natural language processing (NLP) techniques. We evaluate the algorithm on a manually annotated data-set of 20 real-world BP descriptions (1,029 sentences). ABIDE achieves a recall of 87%, and a precision of 56%. We consider these results promising. Improvements of the algorithm are also discussed in the paper.Source: International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management, pp. 140–147, Porto, Portugal, 9-11 November 2016
DOI: 10.5220/0006040301400147

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2012 Conference object Unknown

Lessons learnt from the adoption of formal model-based development.
Ferrari A., Fantechi A., Gnesi S.
This paper reviews the experience of introducing formal model-based design and code generation by means of the Simulink/Stateflow platform in the development process of a railway signalling manufacturer. Such company operates in a standard-regulated framework, for which the adoption of commercial, non qualified tools as part of the development activities poses hurdles from the verification and certification point of view. At this regard, three incremental intermediate goals have been defined, namely (1) identification of a safe-subset of the modelling language, (2) evidence of the behavioural conformance between the generated code and the modelled specification, and (3) integration of the modelling and code generation technologies within the process that is recommended by the regulations. These three issues have been addressed by progressively tuning the usage of the technologies across different projects. This paper summarizes the lesson learnt from this experience. In particular, it shows that formal modelling and code generation are actually powerful means to enhance product safety and cost effectiveness. Nevertheless, their adoption is not a straightforward step, and incremental adjustments and refinements are required in order to establish a formal model-based process.Source: NASA Formal Methods Symposium. 4th International Symposium, pp. 24–36, Norfolk, VA, USA, 3-5 April 2012
DOI: 10.1007/978-3-642-28891-3_5

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2013 Article Unknown

The Metro Rio case study
Ferrari A., Fantechi A., Magnani G., Grasso D., Tempestini M.
This paper reports on the Simulink/Stateflow based development of the on-board equipment of the Metrô Rio Automatic Train Protection system. Particular focus is given to the strategies followed to address formal weaknesses and certification issues of the adopted tool-suite. On the development side, constraints on the Simulink/Stateflow semantics have been introduced and design practices have been adopted to gradually achieve a formal model of the system. On the verification side, a two-phase approach based on model-based testing and abstract interpretation has been followed to enforce functional correctness and runtime error freedom. Formal verification has been experimented as a side activity of the project. Quantitative results are presented to assess the overall strategy: the effort required by the design activities is balanced by the effectiveness of the verification tasks enabled by model-based development and automatic code generation.Source: Science of computer programming (Print) 78 (2013): 828. doi:10.1016/j.scico.2012.04.003
DOI: 10.1016/j.scico.2012.04.003

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2016 Conference object Unknown

Formal methods and safety certification: Challenges in the railways domain
Fantechi A., Ferrari A., Gnesi S.
The railway signalling sector has historically been a source of success stories about the adoption of formal methods in the certification of software safety of computer-based control equipment.Source: Leveraging Applications of Formal Methods, Verification and Validation: Discussion, Dissemination, Applications. 7th International Symposium, pp. 261–265, Corfu, Greece, 10-14 October 2016
DOI: 10.1007/978-3-319-47169-3_18

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2014 Article Restricted

From commercial documents to system requirements: an approach for the engineering of novel CBTC solutions
Ferrari A., Spagnolo G. O., Menabeni S., Martelli G.
Communications-based train control (CBTC) systems are the new frontier of automated train control and operation. Currently developed CBTC platforms are actually very complex systems including several functionalities, and every installed system, developed by a different company, varies in extent, scope, number, and even names of the implemented functionalities. International standards have emerged, but they remain at a quite abstract level, mostly setting terminology. This paper presents the results of an experience in defining a global model of CBTC, by mixing semi-formal modelling and product line engineering. The effort has been based on an in-depth market analysis, not limiting to particular aspects but considering as far as possible the whole picture. The paper also describes a methodology to derive novel CBTC products from the global model, and to define system requirements for the individual CBTC components. To this end, the proposed methodology employs scenario-based requirements elicitation aided with rapid prototyping. To enhance the quality of the requirements, these are written in a constrained natural language (CNL), and evaluated with natural language processing (NLP) techniques. The final goal is to go toward a formal representation of the requirements for CBTC systems. The overall approach is discussed, and the current experience with the implementation of the method is presented. In particular, we show how the presented methodology has been used in practice to derive a novel CBTC architecture.Source: International journal on software tools for technology transfer (Print) (2014): 1–21. doi:10.1007/s10009-013-0298-6
DOI: 10.1007/s10009-013-0298-6

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2016 Other Unknown

User interface for content analysis component
Spagnolo G. O., Ferrari A.
This is the Content Analysis component of the LearnPAd platform. It implements automated procedures to verify that the textual content that describes the tasks of a Business Process (e.g., documents created in the Collaborative Workspace) provides information that is consistent with respect to the Business Process model itself, and to automatically identify ambiguous sentences and vague terms in natural language requirements, and estimates quantitative indexes concerning the linguistic quality of the contents.Project(s): LEARN PAD via OpenAIRE

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2012 Conference object Unknown

A clustering-based approach for discovering flaws in requirements specifications
Ferrari A., Gnesi S., Tolomei G.
In this paper, we present the application of a clustering algorithm to exploit lexical and syntactic relationships occurring between natural language requirements. Our experiments conducted on a real-world data set highlight a correlation between clustering outliers, i.e., requirements that are marked as "noisy" by the clustering algorithm, and requirements presenting "flaws". Those flaws may refer to an incomplete explanation of the behavioral aspects, which the requirement is supposed to provide. Furthermore, flaws may also be caused by the usage of inconsistent terminology in the requirement specification. We evaluate the ability of our proposed algorithm to effectively discover such kind of flawed requirements. Evaluation is performed by measuring the accuracy of the algorithm in detecting a set of flaws in our testing data set, which have been previously manually-identified by a human assessor.Source: 27th Annual ACM Symposium on Applied Computing, pp. 1043–1050, Riva del Garda, Trento, ITALY, 26-30 marzo 2012
DOI: 10.1145/2245276.2231939

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2015 Conference object Open Access OPEN

Ambiguity as a resource to disclose tacit knowledge
Ferrari A., Spoletini P., Gnesi S.
Interviews are the most common and effective means to perform requirements elicitation and support knowledge transfer between a customer and a requirements analyst. Ambiguity in communication is often perceived as a major obstacle for knowledge transfer, which could lead to unclear and incomplete requirements documents. In this paper, we analyse the role of ambiguity in requirements elicitation interviews. To this end, we have performed a set of customer-analyst interviews to observe how ambiguity occurs during requirements elicitation. From this direct experience, we have observed that ambiguity is a multi-dimensional cognitive phenomenon with a dominant pragmatic facet, and we have defined a phenomenological framework to describe the different types of ambiguity in interviews. We have also discovered that, rather than an obstacle, the occurrence of an ambiguity is often a resource for discovering tacit knowledge. Starting from this observation, we have envisioned the further steps needed in the research to exploit these findings.Source: RE 2015 - IEEE 23rd International Requirements Engineering Conference, pp. 26–35, Ottawa, ON, Canada, 24-28 August 2015
DOI: 10.1109/RE.2015.7320405

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2012 Conference object Unknown

Using collective intelligence to detect pragmatic ambiguities.
Ferrari A., Gnesi S.
This paper presents a novel approach for pragmatic ambiguity detection in natural language (NL) requirements specifications defined for a specific application domain. Starting from a requirements specification, we use a Web-search engine to retrieve a set of documents focused on the same domain of the specification. From these domain-related documents, we extract different knowledge graphs, which are employed to analyse each requirement sentence looking for potential ambiguities. To this end, an algorithm has been developed that takes the concepts expressed in the sentence and searches for corresponding concept paths within each graph. The paths resulting from the traversal of each graph are compared and, if their overall similarity score is lower than a given threshold, the requirements specification sentence is considered ambiguous from the pragmatic point of view. A proof of concept is given throughout the paper to illustrate the soundness of the proposed strategy.Source: 20th IEEE International Conference on Requirements Engineering, pp. 191–200, Chicago, Illinois, USA, 24 - 28 September 2012
DOI: 10.1109/RE.2012.6345803

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2011 Article Unknown

Adoption of model-based testing and abstract interpretation by a railway signalling manufacturer
Ferrari A., Magnani G., Grasso D., Fantechi A., Tempestini M.
Introduction of formal model-based practices into the development process of a product in a company implicates changes in the verification and validation activities. A testing process that focuses only on code is not comprehensive in a framework where the building blocks of development are models, and industry is currently heading toward more effective strategies to cope with this new reality. This paper reports the experience of a railway signalling manufacturer in changing its unit level verification process from code-based testing to a two-step approach comprising model-based testing and abstract interpretation. Empirical results on different projects, on which the overall development process was progressively tuned, show that the change paid back in terms of verification cost reduction (about 70%), bug detection, and correction capability.Source: International journal of embedded and real-time communication systems (Online) 2 (2011): 42–61. doi:10.4018/jertcs.2011040103
DOI: 10.4018/jertcs.2011040103

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2016 Other Unknown

Verification component understandability BPMN
Spagnolo G. O., Ferrari A.
In Learn PAd, we developed a quality assessment strategy that allows to guarantee that the used BP models result being understandable by the civil servants. The quality assessment strategy includes modeling understandability guidelines which are supported by a Java tool called verification component understandability BPMN.Project(s): LEARN PAD via OpenAIRE

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2016 Conference object Unknown

Ambiguity cues in requirements elicitation interviews
Ferrari A., Spoletini P., Gnesi S.
Customer-analyst interviews are considered among the most effective means to perform requirements elicitation. However, during these interviews, ambiguity can hamper commu- nication between customer and requirements analyst. Ambiguity is particularly dangerous in those cases in which the analyst misunderstands some linguistic expression of the customer, with- out being aware of the misunderstanding. On the other hand, if the analyst is able to detect ambiguous situations, this has been shown to help him/her in disclosing tacit knowledge. Indeed, the occurrence of an ambiguity might reveal the presence of unexpressed, system-relevant knowledge that needs to be elicited. Therefore, for the requirements elicitation interview to succeed, it is important for the analyst not to overlook ambiguities. To support the ambiguity-awareness of the requirements ana- lyst, this paper aims to provide a set of cues that can be identified in the linguistic expressions of the customer, and that typically lead to ambiguity. To this end, we performed 34 customer- analyst interviews, and we isolated the speech fragments that caused the ambiguity. Based on the analysis of these fragments, and leveraging the previous literature on ambiguity in written requirements, we identified a set of cues that can be used by requirements analysts as a reference handbook to detect ambiguities.Source: 2016 IEEE 24th International Requirements Engineering Conference, pp. 56–65, Beijing, China, 12-16 September 2016
DOI: 10.1109/RE.2016.25

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2010 Conference object Unknown

An industrial application of formal model based development: the Metro Rio ATP case
Ferrari A., Fantechi A., Papini M., Grasso D.
The railway and metro signaling industries are currently investigating strategies for the introduction of formal model based development within their development processes. Among the various platforms supporting this technology, the Simulink/Stateflow tool-suite has been adopted in various safety-critical domains for modeling and code generation of controlsystems. Despite their flexibility and ease of use, introduction of these tools for developing dependable software, and in particular signaling applications, has been often hampered by the lack of a rigorous formal semantic sand by the absence of a certified code generator. This paper reports on the Simulink/Stateflow based development of the on-board equipment of the Metro Rio Automatic Train Protection system, describing the design strategy and the approach followed in addressing weaknesses and certification issues related to the adopted tool-suite.Source: 2nd International Workshop on Software Engineering for Resilient Systems, pp. 71–76, London, UK, 13-16 April 2010
DOI: 10.1145/2401736.2401744

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