Francisco Durán

• PhD Computer Science
• Professor (Full) at University of Malaga

P is a programming language equipped with a unified framework for modeling, specifying, implementing, testing, and verifying complex distributed systems. This language is based on the actor model, and its framework includes a compiler toolchain for code generation, bounded randomized testing, and reachability analysis. This paper presents an extens...

The problem of service composition is the process of assigning resources to services from a pool of available ones in the shortest possible time so that the overall quality of service is maximized. This article provides solutions for the composition problem that takes into account its scalability, services' locations, and users' restrictions, which...

Multilevel Modelling (MLM) approaches make it possible for designers and modellers to work with an unlimited number of abstraction levels to specify their domain-specific modelling languages (DSMLs). To fully exploit MLM techniques, we need powerful model composition operators. Indeed, the composition of DSMLs is becoming increasingly relevant to t...

Business process optimization has become a strategic aspect of companies’ management due to the potential of cost reduction and throughput improvement. There are several ways to achieve process optimization, depending on the level of expressiveness of the processes at hand. In this paper, we focus on processes described using BPMN, but also includi...

Equational unification and matching are fundamental mechanisms in many automated deduction applications. Supporting them efficiently for as wide as possible a class of equational theories, and in a typed manner supporting type hierarchies, benefits many applications; but this is both challenging and nontrivial. We present Maude 3.2’s efficient supp...

Business process optimisation is a strategic activity in organisations because of its potential to increase profit margins and reduce operational costs. One of the main challenges in this context is concerned with the problem of optimising the allocation and sharing of resources. In this work, processes are described using the BPMN notation extende...

Trans-cloud applications consist of multiple interacting components deployed across different cloud providers and at different service layers (IaaS and PaaS). In such complex deployment scenarios, fault handling and recovery need to deal with heterogeneous cloud offerings and to take into account inter-component dependencies. We propose a methodolo...

Multilevel modelling (MLM) approaches make it possible for designers and modellers to work with an unlimited number of abstraction levels when specifying domain-specific modelling languages (DSMLs). In this paper, we present a functional infrastructure that allows modellers to define the structure and the operational semantics of multilevel modelli...

Introduction The Internet of Things consists of devices and software interacting altogether in order to build powerful and added-value services. One of the main challenges in this context is to support end users with simple, user-friendly, and automated techniques to design such applications. IFTTT-style rules are a popular way to build IoT applica...

One of the current challenges in the context of service-oriented applications is the generation of composition plans for applications that optimize their QoS attributes by taking advantage of the resources offered by different providers, and generate them as efficiently as possible. Scalability is indeed a major issue, and the problem becomes a rea...

We are seeing an increase in the number of different languages and design tools used for designing and implementing such systems, fuelled by research in domain-specific modelling languages leading to increasingly more reliable and production-ready environments for language-oriented programming (LOP). While LOP has undeniable benefits for the effici...

Business process optimization is a strategic activity in organizations because of its potential to increase profit margins and reduce operational costs. One of the main challenges in this activity is concerned with the problem of optimizing allocation and sharing of resources. Companies are continuously adjusting their resources to their needs foll...

An adaptive system can modify its settings at runtime as a response to changes in its operational environment. To analyse this kind of systems at design time is a difficult task since it requires considering the system together with the adaptation operations, and taking into account how such adaptations act on the system. In order to use simulation...

This book presents joint works of members of the software engineering and formal methods communities with representatives from industry, with the goal of establishing the foundations for a common understanding of the needs for more flexibility in model-driven engineering. It is based on the Dagstuhl Seminar 19481 "Composing Model-based Analysis Too...

Companies are continuously adjusting their resources to their needs following different strategies. However, the dynamic provisioning strategies are hard to compare. This paper proposes an automatic analysis technique to evaluate and compare the execution time and resource occupancy of a business process relative to a workload and a provisioning st...

The development of applications independent of the cloud providers where they are going to be deployed is still an open issue. In fact, cloud agnostic software development presents important challenges to be solved. One of these issues is the runtime migration of components. Even more difficult is dealing with the interoperability issues when the m...

Terminating functional programs should be deterministic, i.e., should evaluate to a unique result, regardless of the evaluation order. For equational functional programs such determinism is exactly captured by the ground confluence property. For operationally terminating conditional equations this is equivalent to ground local confluence, which fol...

The approach for the modelling and analysis of resource allocation for business processes presented in this paper enables the automatic computation of measures for identifying the allocation of resources in business processes. The proposed analysis, especially suited to support decision-making strategies, is illustrated with a case study of a parce...

Rewriting logic is both a flexible semantic framework within which widely different concurrent systems can be naturally specified and a logical framework in which widely different logics can be specified. Maude programs are exactly rewrite theories. Maude has also a formal environment of verification tools. Symbolic computation is a powerful techni...

Building IoT applications of added-value from a set of available devices with minimal human intervention is one of the main challenges facing the IoT. This is a difficult task that requires models for specifying objects, in addition to user-friendly and reliable composition techniques which in turn prevent the design of erroneous applications. In t...

Rewriting logic is both a flexible semantic framework within which widely different concurrent systems can be naturally specified and a logical framework in which widely different logics can be specified. Maude programs are exactly rewrite theories. Maude has also a formal environment of verification tools. Symbolic computation is a powerful techni...

In this paper, we provide a foundation for the definition and composition of multilevel domain-specific modelling languages. We will introduce modularization techniques such as composition, aggregation and referencing to enhance flexibility and reusability of these languages. To explain this foundation, we use Coloured Petri Nets (CPN) as a paradig...

This paper presents an approach for the modeling and analysis of resource allocation for business processes. It enables the automatic computation of measures for precisely identifying and optimizing the allocation of resources in business processes, including resource usage over time. The proposed analysis, especially suited to support decision-mak...

Term rewriting is a simple, yet expressive model of computation, which finds direct applications in specification and programming languages (many of which embody rewrite rules, pattern matching, and abstract data types), but also indirect applications, e.g., to express the semantics of data types or concurrent processes, to specify program transfor...

The use of Domain-Specific Languages (DSLs) is a promising field for the development of tools tailored to specific problem spaces, effectively diminishing the complexity of hand-made software. With the goal of making models as precise, simple and reusable as possible, we augment DSLs with concepts from multilevel modelling, where the number of abst...

The use of Domain-Specific Languages (DSLs) is a promising field for the development of tools tailored to specific problem spaces, effectively diminishing the complexity of hand-made software. With the goal of making models as precise, simple and reusable as possible, we augment DSLs with concepts from multilevel modelling, where the number of abst...

Multilevel modelling (MLM) tackles the limitation in the number of abstraction levels present in traditional modelling approaches within the model-driven software engineering (MDSE) field. One way to specify the behaviour description of MLMs is by means of multilevel model transformations. In this paper, we propose an approach to achieve reusabilit...

Coloured Petri Nets (CPNs) is a modelling language for distributed systems which has been applied in a multitude of industrial cases. The supporting tool of CPNs is currently lacking important features such as having the possibility of tailoring the tool for specific domains and separation of concerns for facilitating its extensions and adaptation...

Terminating functional programs should be deterministic, i.e., should evaluate to a unique result, regardless of the evaluation order. For equational functional programs such determinism is exactly captured by the ground confluence property. For terminating equations this is equivalent to ground local confluence, which follows from local confluence...

We have added support for associative unification to Maude 2.7.1. Associative unification is infinitary, i.e., there are unification problems \(u =^? v\) such that there is an infinite minimal set of unifiers, whereas associative-commutative unification is finitary. A unique feature of the associative unification algorithm implemented in Maude is t...

The Business Process Model and Notation (\(\text {BPMN}\)) is the standard notation for modeling business processes. It relies on a workflow-based language that allows for the modeling of the control-flow graph of an entire process. In this paper, the main focus is on an extension of \(\text {BPMN}\) with data, which is convenient for describing re...

A business process is a set of structured activities that provide a certain service or product. Business processes can be modeled using the BPMN standard, and several industrial platforms have been developed for supporting their design, modeling, and simulation. This paper presents a rewriting logic executable specification of BPMN with time and ex...

The trans-cloud approach has recently been proposed to simplify the development and operation of cloud applications, and to minimize the lock-in problem. The three key ingredients of the trans-cloud approach are: agnostic topology descriptions, a unified API, and mechanisms for the independent specification of providers’ services. We build on the t...

A business process is a combination of structured and related activities that aim at fulfilling a specific organizational goal for a customer or market. An important measure when developing a business process is the degree of parallelism, namely, the maximum number of tasks that are executable in parallel at any given time in a process. This measur...

Making an application independent of the cloud provider where it is going to be deployed is still an open issue. In fact, cloud agnostic software development still presents important challenges to be solved, and one of them is the problem of runtime migration of components already deployed on a given provider to a different one. Even more difficult...

Predictive analysis methods offer the possibility of estimating the impact of design decisions, which may help in the accomplishment of operational optimal results, before the deployment of the system is made, and therefore minimizing the required maintenance effort and cost. However, current predictive methods are not effective when used on self-a...

We use graph transformation to define an adaptive component model, what allows us to carry on predictive analysis of dynamic architectures through simulations. Specifically, we build on an e-Motions definition of the Palladio component model, and then specify adaptation mechanisms as generic adaptation rules. We show how the simulation-based analys...

The diversity in the way in which different cloud providers offer their services, give their SLAs, present their QoS, or support different technologies complicates the portability and interoperability of cloud applications, and favors vendor lock-in. Trying to solve these issues, we have recently witnessed the proposal of unified APIs for IaaS serv...

The diversity in the way cloud providers offer their services, give their SLAs, present their QoS, or support different technologies, makes very difficult the portability and interoperability of cloud applications, and favours the well-known vendor lock-in problem. We propose a model to describe cloud applications and the required resources in an a...

A business process is a collection of structured activities producing a particular product or software. BPMN is a workflow-based graphical notation for specifying business processes. Formally analyzing such processes is a crucial challenge in order to avoid erroneous executions of the corresponding software. In this paper, we focus on timed busines...

Morphisms between graph-transformation systems (GTSs) have been successfully used for the refinement, reuse, and composition of GTSs. All these uses share a fundamental problem: to be able to define a morphism, source and target GTSs need to be quite similar in their structure (in terms of both the type graphs and the set of rules and their respect...

This paper introduces some novel features of Maude 2.7. We have added support for: (i) built-in order-sorted unification modulo associativity, commutativity, and identity, (ii) built-in variant generation, (iii) built-in order-sorted unification modulo a finite variant theory, and (iv) symbolic reachability modulo a finite variant theory.

Domain experts may use novel tools that allow them to design and model their systems in a notation very close to the domain problem. However, the use of tools for the statistical analysis of stochastic systems requires software engineers to carefully specify such systems in low level and specific languages. In this work we line up both scenarios, s...

Non-Functional Properties (NFPs) are crucial in the design of software. Specification of systems is used in the very first phases of the software development process for the stakeholders to make decisions on which architecture or platform to use. These specifications may be analyzed using different formalisms and techniques, simulation being one of...

Cloud Computing providers offer diverse services and capabilities, which can be used by end-users to compose heterogeneous contexts of multiple cloud platforms to deploy their applications, in accordance with the best offered capabilities. However, this is an ideal scenario, since cloud platforms are being conducted in an isolated way by presenting...

Domain-specific languages (DSLs) become more useful the more specific they are to a particular domain. The resulting need for developing a substantial number of DSLs can only be satisfied if DSL development can be made as efficient as possible. One way in which to address this challenge is by enabling the reuse of (partial) DSLs in the construction...

Cloud applications involve a set of interconnected software components running on remote virtual machines. The deployment and dynamic reconfiguration of cloud applications, involving the addition/removal of virtual machines and components hosted on these virtual machines, are error-prone tasks. They must preserve the application consistency and res...

This paper is a tribute to José Meseguer, from the rest of us in the Maude team, reviewing the past, the present, and the future of the language and system with which we have been working for around two decades under his leadership. After reviewing the origins and the language’s main features, we present the latest additions to the language and som...

How to deploy and manage, in an efficient and adaptive way, complex applications across multiple heterogeneous cloud platforms is one of the problems that have emerged with the cloud revolution. In this paper we present context, motivations and objectives of the EU research project SeaClouds, which aims at enabling a seamless adaptive multi-cloud m...

Maude is a high-level language and high-performance system supporting both equational and rewriting computation for a wide range of applications. Maude also provides a model checker for linear temporal logic. The model-checking procedure can be used to prove properties when the set of states reachable from an initial state in a system is finite; wh...

We address some of the limitations for extending and validat-ing MDE-based implementations of NFP analysis tools by presenting a modular, model-based partial reimplementation of one well-known anal-ysis framework, namely the Palladio Architecture Simulator. We specify the key DSLs from Palladio in the e-Motions system, describing the ba-sic simulat...

The paper presents solutions for the TTC 2014 Movie Database Case, both in the eMotions DSML and in the rewriting-logic formal language Maude. The DSMLs defined in eMotions are automatically transformed into Maude specifications, which are then used for simulation and analysis purposes. eMotions is a general purpose language, in which real-time lan...

Cloud applications involve a set of interconnected software components running on remote virtual machines. Once cloud applications are deployed, one may need to reconfigure them by adding/removing virtual machines or components hosted on these machines. These tasks are error-prone since they must preserve the application consistency and respect imp...

Given a graph-grammar formalization of DSLs, we build on graph transformation system morphisms to define parameterized DSLs and their instantiation by an amalgamation construction. Results on the protection of the behavior along the induced morphisms allow us to safely combine definitions of DSLs to build more complex ones. We illustrate our propos...

We propose an approach for the validation of UML models annotated with OCL constraints. Specifically, we provide support for dynamically validating class invariants and operation pre/post conditions during the execution of prototypes automatically obtained from UML diagrams. The supported UML models specify both static and dynamic aspects, specific...

The modular specification of non-functional properties of systems is a current challenge of Software Engineering, for which no clear solution exists. However, in the case of Domain-Specific Languages some successful proposals are starting to emerge, combining model-driven techniques with aspect-weaving mechanisms. In this paper we show one of these...

ContextDomain-Specific Visual Languages (DSVLs) play a crucial role in Model-Driven Engineering (MDE). Most DSVLs already allow the specification of the structure and behavior of systems. However, there is also an increasing need to model, simulate and reason about their non-functional properties. In particular, QoS usage and management constraints...

Model-driven engineering (MDE) and, in particular, the notion of domain-specific modelling languages (DSMLs) is an increasingly popular approach to systems development. DSMLs are particularly interesting because they allow encoding domain-knowledge into a modelling language and enable full code generation and analysis based on high-level models. Ho...

Domain-specific languages (DSLs) are an important tool for effective system development. They provide concepts that are close to the problem domain and allow analysis as well as generation of full solution implementations. However, this comes at the cost of having to develop a new language for every new domain. To make their development efficient,...

In previous work we have presented an approach to monitor nonfunctional properties of systems modeled in terms of domain specific visual languages using observers. In this work we present an approach to decouple the definition of observers behavior and systems behavior. Having a library with different kinds of observers behavior, and having the beh...

Service-Oriented Computing promotes the development of new systems from existing services which are usually accessed through their public interfaces. In this context, interfaces must be compatible in order to avoid interoperability issues. In this article, we propose a new framework for checking the compatibility of n service interfaces. Our framew...

In the effort to bring rewriting-based methods into contact with practical applications, both in programing and in formal verification, there is a tension between: (i) expressiveness and generality —so that a wide range of applications can be expressed easily and naturally—, and (ii) support for formal verification, which is harder to get for gener...

Maude is a declarative and reflective language based on rewriting logic in which computation corresponds to efficient deduction by rewriting. Because of its reflective capabilities, Maude has been useful as a metatool in the development of formal analysis tools for checking specific properties of Maude specifications. This includes tools for checki...

We present the Maude Formal Environment (MFE), an executable formal specification in Maude within which a user can seamlessly interact with the Maude Termination Tool, the Maude Sufficient Completeness Checker, the Church-Rosser Checker, the Coherence Checker, and the Maude Inductive Theorem Prover. We explain the high-level design decisions behind...

The starting point of this paper is a system described in form of a UML class diagram where system states are characterized by OCL invariants and system transitions are defined by OCL pre- and postconditions. The aim of our approach is to assist the developer in learning about the consequences of the described system states and transitions and abou...

e-Motions is an Eclipse-based visual timed model transformation framework with a Real-Time Maude semantics that supports the usual Maude formal analysis methods, including simulation, reachability analysis, and LTL model checking. e-Motions is characterized by a novel and powerful set of constructs for expressing timed behaviors. In this paper we i...

Over the past years there has been quite a lot of activity in the algebraic community about using algebraic methods for providing support to model-driven software engineering. The aim of this workshop is to gather researchers working on the development and application of algebraic methods to provide rigorous support to model-based software engineer...

This paper presents mOdCL, a Maude based evaluator of OCL expressions and validator of OCL constraints. Given its OCL expression evaluator, the use of execution strategies allows mOdCL, not only validating invariant constraints on concrete system states, but also dynamically validating invariants and pre- and post-conditions on the successive state...

This paper introduces some novel features of Maude 2.6 focusing on the variants of a term. Given an equational theory (Σ,Ax∪E), the E,Ax-variants of a term t are understood as the set of all pairs consisting of a substitution sigma and the E,Ax-canonical form of tσ. The equational theory (Ax∪E) has the finite variant property if there is a finite s...

SMoL is a high-level abstract specification language for P2P systems, expressive enough to capture most of the P2P application fea-tures, and with a precise semantics that makes it susceptible of analyzing a wide range of properties. A Maude implementation of αSMoL allows us to perform automated software verification through a family of formal tool...

Domain specific visual languages (DSVLs) are becoming commonplace for specifying systems at a high-level of abstraction, using a notation very close to the problem domain and quite intuitive for domain experts. Usually, DSVLs are defined only in terms of their abstract and concrete syntaxes, with no precise semantics—something that may hamper the u...

For a rewrite theory to be executable, its equations E should be (ground) confluent and terminating modulo the given axioms A, and their rules should be (ground) coherent with E modulo A. The correctness of many important formal verification tasks, including search, LTL model checking, and the development of abstractions, crucially depends on the t...

The Church-Rosser property, together with termination, is essential for an equational specification to have good executability conditions, and also for having a complete agreement between the specification’s initial algebra, mathematical semantics, and its operational semantics by rewriting. Checking this property for expressive specifications that...

This paper presents the main results and conclusions of the Third Rewrite Engines Competition (REC III). This edition of the competition took place as part of the 8th Workshop on Rewriting Logic and its Applications (WRLA 2010), and the systems ASF+SDF, Maude, Stratego/XT, Tom, and TXL participated in it.

Checking compatibility of services accessed through their behavioural interfaces is a crucial issue in Service Oriented Computing which aims at building new systems from existing software services. In this paper, we consider a model of services which takes value passing and non-observable actions into account. We propose an approach to check in a u...

Modeling languages play a cornerstone role in model-driven software development for representing models and metamodels. Modeling languages are usually defined in terms of their abstract and concrete syntax. This allows the rapid development of languages and some associated tools (e.g. editors), but does not allow the representation of their behavio...

Rewriting with rules R modulo axioms E is a widely used technique in both rule-based programming languages and in automated deduction. Termination methods for rewriting systems modulo specific axioms E (e.g., associativity-commutativity) are known. However, much less seems to be known about termination methods that can be modular in the set E of ax...

This paper presents the Maude Termination Tool (MTT) version 1.5. MTT takes Maude programs as inputs and tries to prove them terminating by applying different transformation techniques and by using existing termination tools as back-ends. MTT can use as back-end tool any termination tool supporting the TPDB syntax, either locally if it follows the...

Domain specific languages (DSLs) play a cornerstone role in Model-Driven Software Development. The abstract syntax of a DSL is usually defined by a metamodel, while in- place model transformation rules provide an intuitive way to complement metamodels with their behavioral specifica- tions. We propose a modeling notation that extends in-place rules...

Despite the remarkable development of the theory of termination of rewriting, its application to high-level (rewriting-based) programming languages is far from being optimal. This is due to the need for features such as conditional equations and rules, types and subtypes, (possibly programmable) strategies for controlling the execution, matching mo...

This work presents a general mechanism for executing specifications that comply with given invariants, which may be expressed in different formalisms and logics. We exploit Maude’s reflective capabilities and its properties as a general semantic framework to provide a generic strategy that allows us to execute Maude specifications taking into accou...

Maude is a high-performance reflective language and system support- ing both equational and rewriting logic specification and programming for a wide range of applications, and has a relatively large worldwide user and open-source developer base. This paper introduces novel features of Maude 2.4 including sup- port for unification and narrowing. Uni...

The Second Rewrite Engines Competition (REC) was celebrated as part of the 7th Workshop on Rewriting Logic and its Applications (WRLA 2008). In this edition of the competition participated five systems, namely ASF+SDF, Maude, Stratego/XT, TermWare, and Tom. We explain here how the competition was organized and conducted, and present its main result...

The goal of this paper is to serve as a practical guide for implementing extensions of Maude by giving an overview of how the Real-Time Maude tool has been developed by extending the implementation of Full Maude. After giving a high-level summary of the key functionality and structure of the implementation of Full Maude, we describe the implementat...