Giorgio Oronzo Spagnolo’s research while affiliated with Italian National Research Council and other places

In this position paper, we discuss the introduction of spatial verification techniques in an application scenario from smart stations, viz. analysing the user experience with respect to the lighting conditions of station areas. This is a case study in industrial projects. We discuss three challenging use cases for the application of spatial model checking in this setting. First, we envision how to use the spatial model checker VoxLogicA, which can analyse both 2D and 3D voxel-based maps, to explore the areas that users can visit in a station area and to characterise them with respect to their illumination conditions. This is aimed at monitoring a smart station. We also ideate statistical spatio-temporal model checking of the design of energy-saving protocols, exploiting the modelling of user preferences. Finally, we discuss the idea of quantifying the impact of design changes, based on the logs of smart stations, to identify and measure the incidence of undesired events (e.g. non-illuminated platforms where a train is passing by) before and after each change.

We provide a brief comparison of the modelling and analysis capabilities of two different formalisms and their associated simulation-based tools, acquired from experimenting with these methods and tools on one specific case study. The case study is a cyber-physical system from an industrial railway project, namely a railroad switch heater, and the quantitative properties concern energy consumption and reliability. We modelled and analysed the case study with stochastic activity networks and Möbius on the one hand and with stochastic hybrid automata and Uppaal SMC on the other hand. We give an overview of the performed experiments and highlight specific features of the two methodologies. This yields some pointers for future research and improvements.

[Context and Motivation] In real-world organisations, business processes (BPs) are often described by means of natural language (NL) documents. Indeed, although semi-formal graphical notations exist to model BPs, most of the legacy process knowledge—when not tacit—is still conveyed through textual procedures or operational manuals, in which the BPs are specified. This is particularly true for public administrations (PAs), in which a large variety of BPs exist (e.g., definition of tenders, front-desk support) that have to be understood and put into practice by civil servants. [Question/problem] Incorrect understanding of the BP descriptions in PAs may cause delays in the delivery of services to citizens, or, in some cases, incorrect execution of the BPs. [Principal idea/results] In this paper, we present the development of an NLP-based tool named QuOD (Quality Analyser for Official Documents), oriented to detect linguistic defects in BP descriptions and to provide recommendations for improvements. [Contribution] QuOD is the first tool that addresses the problem of identifying NL defects in BP descriptions of PAs. The tool is available online at http://narwhal.it/quod/index.html.

In the ever expanding universe of formal methods, several tools exist that can be exploited to validate early system designs, and that are applicable to problems of the railway domain. In this paper, we present an experience report in formal modelling and verification using seven different formal environments, namely UMC, Promela/SPIN, NuSMV, mCRL2, CPN Tools, FDR4 and CADP. In particular, we model and verify an algorithm that addresses a typical railway problem, namely deadlock avoidance in train scheduling. The algorithm is designed according to a prototypical architecture, the so-called blackboard pattern, in which a set of global data are atomically updated by a set of concurrent guarded agents. Our experience, limited to the specific problem, shows that the design of the algorithm can be translated into the different formalisms with acceptable effort, while deep proficiency with the tools is required to optimise the performance. The current paper establishes the preliminary foundations for the concept of formal methods diversity in the development of railway systems. The concept is based on the idea that if different non-certified formal environments are used to verify the same design, this increases the confidence on the verification results. Furthermore, by checking that the number of states generated during the verification process is the same for each framework, the designer can have an initial indication of the equivalence of the diverse models. The industrial application of this promising concept requires further research, and appropriate guidelines shall be established to identify the proper formal environments to use for a specific railway problem, and to define an industrial process in which formal methods diversity can be exploited at its full benefits. The paper presents the different models developed, compares the tools employed in terms of language features and performance, and discusses the industrial implications of the concept of formal methods diversity in the railway domain.

Purpose Business processes of public administrations (PAs) are often described in the form of written procedures or operational manuals. These busi- ness process descriptions are expected to be properly understood and applied by civil servants, who have to provide legally-compliant service provisions to the citizens. However, process descriptions in the PA are sometimes hard to read, ambiguous, or vague, leading to false interpretations or even incorrect execu- tion of the processes. In this paper, we focus on improving the descriptions of business processes to be used in PAs. Design/methodology/approach To this end, we present an in-depth domain analysis, including a literature review and interviews with PA stakeholders belonging to different realities. From this analysis, we identified a set of 52 typical defects of process descriptions. Findings We provide a set of guidelines and a template to constrain the definition of these documents and to mitigate the identified defects. Furthermore, we outline research challenges in the field of quality assessment of textual process descriptions for the PA. Research limitations/implications This paper addresses the needs of any PA officer who has to write an official procedure or operational manual, and should be studied by researchers who wish to provide automatic strategies to check the quality of these documents. Originality/value Text quality issues have been addressed in various fields (e.g., requirements engineering), but not in the area of business process descriptions of PAs. Our contribution consists in the study of the quality issues that occur and create problems in the practice of this particular domain. Based on this insight, we provide directions for research that will find solutions to mitigate the issues.

Business process modeling allows abstracting and reasoning on how work is structured within complex organizations. Business process models represent blueprints that can serve different purposes for a variety of stakeholders. For example, business analysts can use these models to better understand how the organization works; employees playing a role in the process can use them to learn the tasks that they are supposed to perform; software analysts/developers can refer to the models to understand the system-as-is before designing the system-to-be. Given the variety of stakeholders that need to interpret these models, and considering the pivotal function that models play within organizations, understandability becomes a fundamental quality that need to be taken into particular account by modelers. In this paper we provide a set of fifty guidelines that can help modelers to improve the understandability of their models. The work focuses on the Business Process Modelling Notation 2.0 standard published by the Object Management Group, which has acquired a clear predominance among the modeling notations for business processes. Guidelines were derived by means of a thoughtful literature review – which allowed identifying around one hundred guidelines – and through successive activities of synthesis and homogenization. In addition, we implemented a freely available open source tool, named BEBoP (understandaBility vErifier for Business Process models), to check the adherence of a model to the guidelines. Finally, guidelines violation has been checked with BEBoP on a dataset of 11,294 models available in a publicly accessible repository. Our tests show that, although the majority of the guidelines are respected by the models, some guidelines, which are recognized as fundamental by the literature, are frequently violated.