A Game-theoretic approach to analyze interacting actors in GRL goal models

Goal-oriented requirements engineering aims to capture desired goals and strategies of relevant stakeholders during early requirements engineering stages, using goal models. Goal-oriented modeling techniques support the analysis of system requirements (especially non-functional ones) from an operationalization perspective, through the evaluation of alternative design options. However, conflicts and undesirable interactions between requirements produced from goals are inevitable, especially as stakeholders often aim for different objectives. In this paper, we propose an approach based on game theory and the Goal-oriented Requirement Language (GRL) to reconcile interacting stakeholders (captured as GRL actors), leading to reasonable trade-offs. This approach consists in building a payoff bimatrix that considers all actor’s valid GRL strategies, and computing its Nash equilibrium. Furthermore, we use two optimization techniques to reduce the size of the payoff bimatrix, hence reducing the computational cost of the Nash equilibrium. The approach goes beyond existing work by supporting nonzero-sum games, multiple alternatives, and inter-actor dependencies. We demonstrate the applicability of our game-theoretic modeling and analysis approach using a running example and two GRL models from the literature, with positive results on feasibility and applicability, including performance results.

     

Business process management with the user requirements notation

A number of recent initiatives in both academia and industry have sought to achieve improvements in e-businesses through the utilization of Business Process Management (BPM) methodologies and tools. However there are still some inadequacies that need to be addressed when it comes to achieving alignment between business goals and business processes. The User Requirements Notation (URN), recently standardized by ITU-T, has some unique features and capabilities beyond what is available in other notations that can help address alignment issues. In this paper, a URN-based framework and its supporting toolset are introduced which provide business process monitoring and performance management capabilities integrated across the BPM lifecycle. The framework extends the URN notation with Key Performance Indicators (KPIs) and other concepts to measure and align processes and goals. An example process for controlling access to a healthcare data warehouse is used to illustrate and evaluate the framework. Early results indicate the feasibility of the approach.     

An empirical approach toward the resolution of conflicts in goal-oriented models

One significant problem requirements engineers have to cope with is the management of unclear requirements, ambiguities, and conflicts that may arise between stakeholders. Such issues may be desirable since they may allow for further elicitation of requirements that would have been missed otherwise. Goal models capture the objectives and other intentions of different stakeholders, together with their relationships. They can be used to refine unclear requirements and to detect conflicts and ambiguities early during model validation. However, resolving such ambiguities and conflicts is key for the successful implementation of the goal models. In this paper, we propose a novel approach to validate models in the Goal-oriented Requirement Language and resolve conflicts between the perspectives of intervening stakeholders (and especially between stakeholders of a given group). Our approach is based on a statistical analysis of empirical data that we collect from surveys designed for each group of stakeholders. We apply concept analysis in order to fix goal-model artifacts that are subject to conflict. We illustrate our approach using a case study of a goal model describing the involvement of undergraduate students in university research activities.     

Photooxidation of Hg(0) in artificial and natural waters

The oxidation of volatile aqueous Hg(0) in aquatic systems may be important in reducing fluxes of Hg out of aquatic systems. Here we report the results of laboratory and field experiments designed to identify the parameters that control the photooxidation of Hg(0)(aq) and to assess the possible importance of this process in aquatic systems. The concentrations of elemental and total Hg were measured as a function of time in both artificial and natural waters irradiated with a UV-B lamp. No change in Hg speciation was observed in dark controls, while a significant decrease in Hg(0) was observed in UV-B irradiated artificial solutions containing both chloride ions and benzoquinone. Significant photooxidation rates were also measured in natural samples spiked with Hg(0)(aq); the photooxidation of Hg(0) then follows pseudo first-order kinetics (k = 0.6 h(-1)). These results indicate that the previously observed Hg(II) photoreduction rates in natural waters could represent a net balance between Hg(0) photoreduction and Hg(0) photooxidation. As calculated from Hg(0) photooxidation rates, the dominant Hg(0) sink is likely to be photooxidation rather than volatilization from the water column during summer days.     

Expanding the nature and scope of requirements for service systems through Service-Dominant Logic: the case of a telemonitoring service

Requirements Engineering - A renewed understanding of service as a process of resource application and integration, rather than as digital or physical products, shifts the focus of service...     

GoRIM: a model-driven method for enhancing regulatory intelligence

Regulators are under constant pressure to demonstrate if and how the regulations they administer, which impose many requirements on various systems and processes, achieve intended societal outcomes. Traditionally, regulators have relied on impact assessments, risk analysis, and cost–benefit analysis to assess compliance with regulations. These methods, however, are effort and time intensive and focus on the efficiency of regulatory processes rather than on the effectiveness of the regulatory initiatives meant to improve compliance to regulations and the latter’s impact on intended societal outcomes. Goal-oriented modelling and data analytics approaches provide the basis for the development of more sophisticated methods and tools to better address the needs of regulators. This paper introduces the goal-oriented regulatory intelligence method (GoRIM), which enables effective management of regulations through modelling and data analytics. Through continuous monitoring, assessing, and reporting on efficiency and effectiveness aspects, GoRIM is meant to facilitate the analysis of feedback loops between regulations, regulatory initiatives, and societal outcomes. To demonstrate the applicability and perceived usefulness of GoRIM in addressing the first feedback loop between regulations and initiatives, we evaluated it through three case studies involving regulators from different contexts, with positive results. GoRIM extends the concept of regulatory intelligence beyond the analysis of compliance. It also provides practical guidelines and tools to regulators for making, in a timely way, evidence-based decisions related to the addition, modification, or repeal of regulations and related regulatory initiatives. In addition, GoRIM helps better identify software and information needs for enabling such decisions.

     

A questionnaire-based survey methodology for systematically validating goal-oriented models

Goal models represent interests, intentions, and strategies of different stakeholders. Reasoning about the goals of a system unavoidably involves the transformation of unclear stakeholder requirements into goal-oriented models. The ability to validate goal models would support the early detection of unclear requirements, ambiguities, and conflicts. In this paper, we propose a novel validation approach based on the Goal-oriented Requirement Language (GRL) to check the correctness of GRL goal models through statistical analyses of data collected from generated questionnaires. System stakeholders (e.g., customers, shareholders, and managers) may have different objectives, interests, and priorities. Stakeholder conflicts arise when the needs of some group of stakeholder compromise the expectations of some other group(s) of stakeholders. Our proposed approach allows for early detection of potential conflicts amongst intervening stakeholders of the system. In order to illustrate and demonstrate the feasibility of the approach, we apply it to a case study of a GRL model describing the fostering of the relationship between the university and its alumni. The approach brings unique benefits over the state of the art and is complementary to existing validation approaches.     

Gross photoreduction kinetics of mercury in temperate freshwater lakes and rivers: application to a general model of DGM dynamics

Previous published measurements of mercury photoreduction are for net-photoreduction, since photooxidation processes occur simultaneously. In this research we combine continuous dissolved-gaseous mercury (DGM) analysis with a photoreactor and a quartz sparger in order to derive mercury gross photoreduction rate constants for UVB and UVA irradiations. The DGM concentration in each filter-sterilized freshwater was measured at 5 min intervals over a period of 23 h. Photoreduction proceeded for the initial 200 min, after which, reducible mercury was depleted in the sample. Substantial losses in DOC fluorescence were observed during the incubations for UVA radiation but not for UVB; therefore, UVB photoreduction dynamics are not linked to a loss in DOC fluorescence. Pseudo first-order reaction kinetics fit the data well (r2 > 0.87). The rate constants appear divided between lakes and rivers with the mean lake UVB rate constant (kUVB = 8.91 x 10(-5) s(-1)), significantly less than the mean rate constant (kUVB = 1.81 x 10(-4) s(-1)) for the river samples. However, while there were differences for the UVB rates between lakes and rivers, the mean and median rate constants for UVA in lakes (kUVA = 7.76 x 10(-5) s(-1)) did not differ significantly from the mean rate constant forthe river sites (kUVA = 1.78 x 10(-4) s(-1)). Here, we propose a model for mercury photoredox dynamics for both temperate lake and river systems. The lake model was validated using principal axis analysis to compare observed and predicted DGM data (n=279) from a variety of lake sites in Nova Scotia and Central Quebec. Principal axis analysis found a linear fit (correlation = 0.81; slope = 2.13) between predicted and observed environmental DGM values when log-normalized. The constant bias on the predicted values was attributed to estimates of available reducible mercury and the effect of DGM volatilization on observed data.