Mutation Analysis for the Evaluation of AD Models

UML has became the industry standard for analysis and design modeling. Model is a key artifact in Model Driven Architect (MDA) and considered as an only concrete artifact available at earlier development stages. Error detection at earlier development stages can save enormous amount of cost and time. The article presents a novel mutation analysis technique for UML 2.0 Activity Diagram (AD). Based on the AD oriented fault types, a number of mutation operators are defined. The technique focuses on the key features of AD and enhances the confidence in design correctness by showing the absence of control-flow and concurrency related faults. It will enable the automated analysis technique of AD models and can potentially be used for service oriented applications, workflows and concurrent applications

Towards Automated Test Sequence Generation

The article presents a novel control-flow based test sequence generation technique using UML 2.0 activity diagram, which is a behavioral type of UML diagram. Like other model-based techniques, this technique can be used in the earlier phases of the development process owing to the availability of the design models of the system. The activity diagram model is seamlessly converted into a colored Petri net. We proposed a technique that enables the automatic generation of test sequences according to a given coverage criteria from the execution of the colored Petri nets model. Two types of structural coverage criteria for AD based models, namely sequential and concurrent coverage are described. The proposed technique was applied to an example to demonstrate its feasibility and the generated test sequences were evaluated against selected coverage criteria. This technique can potentially be adapted to service oriented applications, workflows, and concurrent applications

Pattern-based analysis of UML activity diagrams

The Unified Modelling Language (UML) is a well-known family of notations for software modelling. Recently, a new version of UML has been released. In this paper we examine the Activity Diagrams notation of this latest version of UML in terms of a collection of patterns developed for assessing control flow and data flow capabilities of languages used in the area of process-aware information systems. The purpose of this analysis is to assess relative strengths and weaknesses of control and data flow specification in Activity Diagrams and to identify ways of addressing potential deficiencies. In addition, the pattern-based analysis will yield typical solutions to practical process modelling problems and expose some of the ambiguities in the current UML 2.0 draft specificatio

Un conjunto de medidas para la evaluación de modelos workflow

En todo proceso de negocio es muy importante su mejora continua, lo que lleva a las organizaciones a buscar herramientas que den soporte a la realización de estas mejoras. La Gestión de Procesos de Negocio proporciona este soporte mediante los Sistemas de Gestión de Procesos de Negocio (BPMS). Una de las tecnologías más significativas para dar soporte a la automatización de los procesos de negocio son los Sistemas de Gestión de Workflow (SGW). Para favorecer y dar flexibilidad a los SGW, de manera que puedan adaptarse a los cambios constantes del negocio, es fundamental tener un lenguaje de modelado que permita una fácil adaptación de los modelos. De la misma manera es fundamental tener herramientas que permitan medir la calidad de dichos modelos. En función de esto, proponemos un conjunto de métricas para la evaluación de modelos workflows en función de su adaptabilidad y entendibilidad.Workshop de Ingeniería de Software y Bases de Datos (WISBD)Red de Universidades con Carreras en Informática (RedUNCI

Un conjunto de medidas para la evaluación de modelos workflow

En todo proceso de negocio es muy importante su mejora continua, lo que lleva a las organizaciones a buscar herramientas que den soporte a la realización de estas mejoras. La Gestión de Procesos de Negocio proporciona este soporte mediante los Sistemas de Gestión de Procesos de Negocio (BPMS). Una de las tecnologías más significativas para dar soporte a la automatización de los procesos de negocio son los Sistemas de Gestión de Workflow (SGW). Para favorecer y dar flexibilidad a los SGW, de manera que puedan adaptarse a los cambios constantes del negocio, es fundamental tener un lenguaje de modelado que permita una fácil adaptación de los modelos. De la misma manera es fundamental tener herramientas que permitan medir la calidad de dichos modelos. En función de esto, proponemos un conjunto de métricas para la evaluación de modelos workflows en función de su adaptabilidad y entendibilidad.Workshop de Ingeniería de Software y Bases de Datos (WISBD)Red de Universidades con Carreras en Informática (RedUNCI

On formalizing UML2 activities using TPNets: case studies

ABSTRACT: Transactional Petri Nets (TPNets) are a new class of high-level Zero-Safe Nets (ZSNs), defined as a more suitable semantic framework for UML2 activity diagrams. Indeed, they ensure reactivity and synchronization of concurrent flows triggering with their junction. Reactivity is guaranteed due to the real time massive cancellation semantics based on the definition of new dynamic enabling rules and the imposed priority among executions. Global synchronization in turn is assured thanks to non-locality principle, an outcome of exploiting atomic stable transactions. Rewriting logic is defined as the operational semantics framework of TPNets

Operating guidelines for services

In the paradigm of service-oriented computing, companies organize their core competencies as services and may request other functionalities from services of other companies. Services provide high flexibility, platform independent loose coupling, and distributed execution. They may thus help to reduce the complexity of dynamically binding and integrating heterogenous processes within and across organizations. The vision of service-oriented architectures is to provide a framework for publishing new services, for on demand searching for and discovery of existing services, and for dynamically binding services to achieve common business goals. That way, each individual organization gains more flexibility to dynamically react on new challenges. As services may be created or modified, or collaborations may be restructured at any point in time, a new challenge arises in this setting—the challenge for deciding the compatibility of the composed services before their actual binding. Recent literature distinguishes four different aspects of service compatibility: syntactical, behavioral, semantical, and non-functional compatibility. In this thesis, we focus on behavioral compatibility and abstract from the other aspects. Potential behavioral incompatibilities between services include deadlocks (two services wait for a message of each other), livelocks (two services keep exchanging messages without progressing), and pending messages that have been sent but cannot be received anymore. For stateful services that interact via asynchronous message passing, deciding behavioral compatibility is far from trivial. Local changes to one service may introduce errors in some or even all other services of an interaction. The verification of behavioral compatibility suffers from state explosion problems and is restricted by privacy issues. That is, the parties of an interaction are essentially autonomous and may be competitors in other business fields. Consequently, they do not want to reveal the internals of their processes to the other participants in order to hide trade secrets. To systematically approach this challenge, we introduce a formal framework based on Petri nets and automata for service modeling and formalize behavioral compatibility as deadlock freedom of the composition of the services. The main contribution of this thesis is to introduce the concept of the operating guideline of a service. Operating guidelines provide a formal characterization of the set of all behaviorally compatible services R for a given service S. Usually, this set is infinite. However, the operating guideline OGS of a service S serves as a finite representation of this infinite set. Furthermore, the operating guideline of S reveals only internals that are inevitably necessary to decide behavioral compatibility with S. We provide a construction method of operating guidelines for finite-state services with bounded communication. Operating guidelines can be used in many applications in the context of serviceoriented computing. The most fundamental application is to support the discovery of behaviorally compatible services. To this end, we develop a matching procedure that efficiently decides whether a given service R is characterized by the operating guideline OGS of a service S. If R matches, then both services R and S are behaviorally compatible and can be bound together to interact with each other. If R does not match with OGS, then the services are behaviorally incompatible and may run into severe behavioral errors and not reach their common business goal. Operating guidelines can furthermore be applied in the novel research areas of service substitutability and the generation of adapter services, for instance. To this end, we develop methods to compare the sets of services characterized by the operating guidelines OGS and OGS0 . If OGS0 characterizes more services than OGS, then the service S can be substituted by the service S0 without loosing any behaviorally compatible interaction partner R. Furthermore, we show how to synthesize a service R from the operating guideline OGS such that R is behaviorally compatible to S by construction. All results presented in this thesis are implemented in our service analysis tool Fiona. Fiona may compute operating guidelines for services modeled as Petri nets. It may match a service with an operating guideline, compare operating guidelines for equivalence or an inclusion relation, and synthesize service adapters for behaviorally incompatible services. Together with the tool BPEL2oWFN— which translates web services specified in BPEL into Petri net models of the services—we can immediately apply our results to services that stem from practic

Model based test suite minimization using metaheuristics

Software testing is one of the most widely used methods for quality assurance and fault detection purposes. However, it is one of the most expensive, tedious and time consuming activities in software development life cycle. Code-based and specification-based testing has been going on for almost four decades. Model-based testing (MBT) is a relatively new approach to software testing where the software models as opposed to other artifacts (i.e. source code) are used as primary source of test cases. Models are simplified representation of a software system and are cheaper to execute than the original or deployed system. The main objective of the research presented in this thesis is the development of a framework for improving the efficiency and effectiveness of test suites generated from UML models. It focuses on three activities: transformation of Activity Diagram (AD) model into Colored Petri Net (CPN) model, generation and evaluation of AD based test suite and optimization of AD based test suite. Unified Modeling Language (UML) is a de facto standard for software system analysis and design. UML models can be categorized into structural and behavioral models. AD is a behavioral type of UML model and since major revision in UML version 2.x it has a new Petri Nets like semantics. It has wide application scope including embedded, workflow and web-service systems. For this reason this thesis concentrates on AD models. Informal semantics of UML generally and AD specially is a major challenge in the development of UML based verification and validation tools. One solution to this challenge is transforming a UML model into an executable formal model. In the thesis, a three step transformation methodology is proposed for resolving ambiguities in an AD model and then transforming it into a CPN representation which is a well known formal language with extensive tool support. Test case generation is one of the most critical and labor intensive activities in testing processes. The flow oriented semantic of AD suits modeling both sequential and concurrent systems. The thesis presented a novel technique to generate test cases from AD using a stochastic algorithm. In order to determine if the generated test suite is adequate, two test suite adequacy analysis techniques based on structural coverage and mutation have been proposed. In terms of structural coverage, two separate coverage criteria are also proposed to evaluate the adequacy of the test suite from both perspectives, sequential and concurrent. Mutation analysis is a fault-based technique to determine if the test suite is adequate for detecting particular types of faults. Four categories of mutation operators are defined to seed specific faults into the mutant model. Another focus of thesis is to improve the test suite efficiency without compromising its effectiveness. One way of achieving this is identifying and removing the redundant test cases. It has been shown that the test suite minimization by removing redundant test cases is a combinatorial optimization problem. An evolutionary computation based test suite minimization technique is developed to address the test suite minimization problem and its performance is empirically compared with other well known heuristic algorithms. Additionally, statistical analysis is performed to characterize the fitness landscape of test suite minimization problems. The proposed test suite minimization solution is extended to include multi-objective minimization. As the redundancy is contextual, different criteria and their combination can significantly change the solution test suite. Therefore, the last part of the thesis describes an investigation into multi-objective test suite minimization and optimization algorithms. The proposed framework is demonstrated and evaluated using prototype tools and case study models. Empirical results have shown that the techniques developed within the framework are effective in model based test suite generation and optimizatio