A Lightweight Modeling Approach Based on Functional Decomposition

in Journal of Object Technology (2020), 19(2), 151-22

Creating models and transforming them using current MDE techniques is not easy: it generally requires mastering several non-trivial languages such as a metamodeling languages and a model transformation ... [more ▼]

Creating models and transforming them using current MDE techniques is not easy: it generally requires mastering several non-trivial languages such as a metamodeling languages and a model transformation language. We propose a two-pronged approach for tackling language complexity for the case of model-to-text transformations. We first allow the user to define the metamodel in an example-driven fashion in which (s)he incrementally builds a set of examples and automatically infers the metamodel from them. The example-driven approach is based on a new object-modelling notation named OYAML that is both human- and machine- readable. Second we break down the complexity of writing the transformation itself by separately defining the functional decomposition of the transformation function using a new modelling language named FUDOMO. This will then allow the user to describe the precise behaviour in a general purpose programming language that (s)he is familiar with. Because they do not need to be very expressive, OYAML and FUDOMO are small languages when compared to commonly used metamodeling and model-to-text transformation languages. We provide a web-based tool, also named FUDOMO, that assists the user in this example-driven approach to model-to-text transformations and currently supports the use of Javascript and Python for defining the precise behaviour of model transformations. [less ▲]

F-Alloy: a relational model transformation language based on Alloy

in Software and Systems Modeling (2019), 18(1), 213-247

Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In ... [more ▼]

Model transformations are one of the core artifacts of a model-driven engineering approach. The relational logic language Alloy has been used in the past to verify properties of model transformations. In this paper we introduce the concept of functional Alloy modules. In essence a functional Alloy module can be viewed as an Alloy module representing a model transformation. We describe a sublanguage of Alloy called F-Alloy specifically designed to concisely specify functional Alloy modules. The restrictions on F-Alloy’s syntax are meant to allow efficient execution of the specified transformation, without the use of backtracking, by an adapted interpretation algorithm. F-Alloy’s semantics is given in this paper as a direct translation to Alloy; hence, F-Alloy specifications are also analyzable using the powerful automatic analysis features of Alloy. [less ▲]

Agile Validation of Model Transformations using Compound F-Alloy Specifications

in Science of Computer Programming (2017)

Model transformations play a key role in model driven software engineering approaches. Validation of model transformations is crucial for the quality assurance of software systems to be constructed. The ... [more ▼]

Model transformations play a key role in model driven software engineering approaches. Validation of model transformations is crucial for the quality assurance of software systems to be constructed. The relational logic based specification language Alloy and its accompanying tool the Alloy Analyzer have been used in the past to validate properties of model transformations. However Alloy based analysis of transformations suffers from several limitations. On one hand, it is time consuming and does not scale well. On the other hand, the reliance on Alloy, being a formal method, prevents the effective involvement of domain experts in the validation process which is crucial for pinpointing domain pertinent errors. Those limitations are even more severe when it comes to transformations whose input and/or output are themselves transformations (called compound transformations) because they are inherently more complex. To tackle the performance and scalability limitations, in previous work, we proposed an Alloy-based Domain Specific Language (DSL), called F-Alloy, that is tailored for model transformation specifications. Instead of pure analysis based validation, F-Alloy speeds up the validation of model transformations by applying a hybrid strategy that combines analysis with interpretation. In this paper, we formalize the notion of “hybrid analysis” and further extended it to also support efficient validation of compound transformations. To enable the effective involvement of domain experts in the validation process, we propose in this paper a new approach to model transformation validation, called Visualization-Based Validation (briefly VBV). Following VBV, representative instances of a to-be-validated model transformation are automatically generated by hybrid analysis and shown to domain experts for feedback in a visual notation that they are familiar with. We prescribe a process to guide the application of VBV to model transformations and illustrate it with a benchmark model transformation. [less ▲]

A generic model decomposition technique and its application to the Eclipse modeling framework

in Software and Systems Modeling (2015), 14(2), 921-952

Model-driven software development aims at easing the process of software development by using models as primary artifacts. Although less complex than the real systems they are based on, models tend to be ... [more ▼]

Model-driven software development aims at easing the process of software development by using models as primary artifacts. Although less complex than the real systems they are based on, models tend to be complex nevertheless, thus making the task of handling them non-trivial in many cases. In this paper we propose a generic model decomposition technique to facilitate model management by decomposing complex models into smaller sub-models that conform to the same metamodel as the original model. The technique is based upon a formal foundation that consists of a formal capturing of the concepts of models, metamodels, and model conformance; a formal constraint language based on EssentialOCL; and a set of formally proved properties of the technique. We organize the decomposed sub-models in a mathematical structure as a lattice, and design a linear-time algorithm for constructing this decomposition. The generic model decomposition technique is applied to the Eclipse Modeling Framework (EMF) and the result is used to build a solution to a specific model comprehension problem of Ecore models based upon model pruning. We report two case studies of the model comprehension method: one in BPMN and the other in fUML. [less ▲]

Designing Languages using Lightning

in Proceedings of the 2015 ACM SIGPLAN International Conference on Software Language Engineering (2015)

Modelling languages are defined by specifying their abstract syntax, concrete syntax and semantics. In the Lightning tool the definition of all these language components is based on the lightweight formal ... [more ▼]

Modelling languages are defined by specifying their abstract syntax, concrete syntax and semantics. In the Lightning tool the definition of all these language components is based on the lightweight formal language Alloy. Lightning makes use of the powerful automatic analysis features of Alloy to allow language designers to develop and validate the definition of a modelling language in an incremental fashion. By providing immediate visual feedback, it allows errors in the language definition to be quickly identified and corrected. Furthermore Lightning introduces a novel interpretation mechanism that allows efficient execution of transformations used in the language definition. We illustrate the use of the tool on the language of structured business processes. [less ▲]

Algorithms for tractable compliance problems

in Frontiers of Computer Science (2015), 9(1), 55-74

In general the problem of verifying whether a structured business process is compliant with a given set of regulations is NP-hard. The present paper focuses on identifying a tractable subset of this ... [more ▼]

In general the problem of verifying whether a structured business process is compliant with a given set of regulations is NP-hard. The present paper focuses on identifying a tractable subset of this problem, namely verifying whether a structured business process is compliant with a single global obligation. Global obligations are those whose validity spans for the entire execution of a business process. We identify two types of obligations: achievement and maintenance. In the present paper we firstly define an abstract framework capable to model the problem and secondly we define procedures and algorithms to deal with the compliance problem of checking the compliance of a structured business process with respect to a single global obligation. We show that the algorithms proposed in the paper run in polynomial time. [less ▲]

Functional Alloy Modules

Report (2014)

The Alloy language was developed as a lightweight modelling language that allows fully automatic analysis of software design models via SAT solving. The practical application of this type of analysis is ... [more ▼]

The Alloy language was developed as a lightweight modelling language that allows fully automatic analysis of software design models via SAT solving. The practical application of this type of analysis is hampered by two limitations: first, the analysis itself can become quite time consuming when the scopes become even moderately large; second, determining minimal scopes for the entity types (limiting the number of entities of each type) to achieve better running times is itself a non-trivial problem. In this paper we show that for the special case of Alloy modules specifying transformations we may be able to circumvent these limitations. We define the corresponding notion of functional module and define precise conditions under which such functional modules can be efficiently interpreted rather than analysed via SAT solving and we also explain how interpretation of functional Alloy modules can be seamlessly integrated with the SAT-based analysis of other modules. We provide evidence that for complex transformations interpreting functional modules may result in significant time savings. [less ▲]

Verifying Modelling Languages using Lightning: a Case Study

in MoDeVVa 2014: Model-Driven Engineering, Verification and Validation (2014)

The formal language Alloy was developed to provide fully automatic analysis of software designs. By providing immediate feedback to users it allows early detection of design errors. The main goal of the ... [more ▼]

The formal language Alloy was developed to provide fully automatic analysis of software designs. By providing immediate feedback to users it allows early detection of design errors. The main goal of the Lightning tool is to apply the power of Alloy's automatic analysis to the domain of software language engineering. The tool allows to represent abstract syntax, concrete syntax and semantics of a modelling language in Alloy. In this paper we describe the verification capabilities of Lightning with the help of a concrete modelling language, namely the language of structured business processes. [less ▲]

Towards an Abstract Framework for Compliance

in Bagheri, Ebrahim; Gasevic, Dragan; Halle, Sylvain (Eds.) et al Proceedings of the 17th IEEE International EDOC 2013 Conference Workshops, Vancouver, Canada, 9 September 2013. (2013, September 09)

The present paper aims at providing an abstract framework to define the regulatory compliance problem. In particular we show how the framework can be used to solve the problem of deciding whether a ... [more ▼]

The present paper aims at providing an abstract framework to define the regulatory compliance problem. In particular we show how the framework can be used to solve the problem of deciding whether a structured process is compliant with a single regulation, which is composed of a primary obligation and a chain of compensations. [less ▲]

Visual Modelling of and on Tangible User Interfaces

Report (2012)

The purpose of this thesis is to investigate the use and benefit of visual modelling languages (VMLs) in modelling on tangible user interfaces (TUIs), and modelling TUI applications. Three main research ... [more ▼]

The purpose of this thesis is to investigate the use and benefit of visual modelling languages (VMLs) in modelling on tangible user interfaces (TUIs), and modelling TUI applications. Three main research questions are asked: - Is it possible and practical to model an application or process using a TUI? - Which General-purpose VML (GPVML) performs best in modelling a VML scenario for use on TUI? - Is it realistic to use a GPVML to model complex TUI applications? To answer the first research question, a Business Process Model and Notation, version 2 (BPMN2), ideation scenario is used with a tangible widget toolkit prototype on a TUI table to evaluate the performance and obtain feedback from test candidates. The study showed that it is possible to model a process using a TUI and the test candidate feedback did not lead to the conclusion that the modelling was cumbersome or impractical. To find a suitable GPVML, the thesis explores and evaluates the current state of the art in VMLs for describing general problems. After gathering different VMLs, the thesis compares three languages using a simple scenario: the visual object constraint language (VOCL), augmented constraint diagrams (ACD), and the visual contract language (VCL). A weighted evaluation based on multiple quality criteria led to the conclusion that VCL is best suited to model TUI applications, answering the second research question. The thesis answers the third research question by using VCL to model a more complex and complete scenario of an ideation process, which is based on using a BPMN2 on a TUI. This is done to assess VCL's suitability to more complex problems and its maturity. The study concludes that VCL is not yet mature enough to enable its general applicability in a wide variety of settings. The three research questions were dressed with a hypothesis in mind: collaborative, novice friendly modelling environments are able to reduce the gap between stakeholders and software engineers during software projects, leading to a reduction of unrealistic expectations and an increase in the availability of domain knowledge. While the hypothesis is too broad to be proven by this thesis, the research questions answered here give some insights into how to approach it. [less ▲]