Using formal metamodels to check consistency of functional views in information systems specification

UML notations require adaptation for applications such as Information Systems (IS). Thus we have defined IS-UML. The purpose of this article is twofold. First, we propose an extension to this language to deal with functional aspects of IS. We use two views to specify IS transactions: the first one is defined as a combination of behavioural UML diagrams (collaboration and state diagrams), and the second one is based on the definition of specific classes of an extended class diagram. The final objective of the article is to consider consistency issues between the various diagrams of an IS-UML specification. In common with other UML languages, we use a metamodel to define IS-UML. We use class diagrams to summarize the metamodel structure and a formal language, B, for the full metamodel. This allows us to formally express consistency checks and mapping rules between specific metamodel concepts.     

A framework for an integrated unified modeling language

The unified modeling language (UML) is one of the most commonly used modeling languages in the software industry. It simplifies the complex process of design by providing a set of graphical notations, which helps express the objectoriented analysis and design of software projects. Although UML is applicable to different types of systems, domains, methods, and processes, it cannot express certain problem domain needs. Therefore, many extensions to UML have been proposed. In this paper, we propose a framework for integrating the UML extensions and then use the framework to propose an integrated unified modeling language-graphical (iUML-g) form. iUML-g integrates the existing UML extensions into one integrated form. This includes an integrated diagram for UML class, sequence, and use case diagrams. The proposed approach is evaluated using a case study. The proposed iUML-g is capable of modeling systems that use different domains.     

A metamodeling approach for pattern specification and management

The formal specification of design patterns is central to pattern research and is the foundation of solving various pattern-related problems.In this paper,we propose a metamodeling approach for pattern specification,in which a pattern is modeled as a meta-level class and its participants are meta-level references.Instead of defining a new metamodel,we reuse the Unified Modeling Language(UML)metamodel and incorporate the concepts of Variable and Set into our approach,which are unavailable in the UML but essential for pattern specification.Our approach provides straightforward solutions for pattern-related problems,such as pattern instantiation,evolution,and implementation.By integrating the solutions into a single framework,we can construct a pattern management system,in which patterns can be instantiated,evolved,and implemented in a correct and manageable way.     

基于活动图的C4ISR能力需求过程建模及验证

当前对C⁴ISR系统能力需求的描述大多基于图形、文字等静态模型,对信息和数据的具体操作没有进行定义,以至于对象之间的行为过程没有详细说明。缺乏可执行动态语义的能力模型是不可执行的,因此提出了一种基于活动图的能力需求过程建模方法,为可执行体系结构的建模仿真提供支撑。首先给出了系统过程模型的定义,在C⁴ISR系统能力元概念模型的指导下,通过扩展UML活动图得到系统的能力需求过程元模型。然后用本体表示能力需求过程元模型语义,通过对本体的逻辑推理实现对C⁴ISR系统能力需求过程元模型的验证。     

一种Concur任务树转化为UML2．0的方法

Concur任务树是一种具有代表性的图形化用户界面任务建模方法。UML2．0缺少对用户界面设计的支持,针对该问题在UML2．0中引入Concur任务树。利用基于元模型的扩展机制对UML2．0活动图进行扩展,建立Concur任务树的元模型及其表示法。应用结果表明,该方法不会丢失Concur任务树的任务分类特性。     

A proposal for extending UML-B to support a conceptual model

UML-B is a development process framework for Event-B based on a “UML-like” graphical formal notation that provides support for object-oriented modelling concepts, in particular, for class and state machine diagrams. However, this methodology has a gap for mapping requirements to formal specifications. To overcome this issue, we present a proposal for extending UML-B to support a conceptual model to provide an easier starting point for the actual development process. More precisely, we propose two diagrams to facilitate the passing from requirements to the initial formal model: a first one to represent system behavior based on UML 2 interaction overview diagram (IOD) and a second one for system structure based on boundary-control-entity stereotyped class diagram (BCE). We show how to translate the former into an Event-B specification and explain how to link the latter to the original UML-B using a simple ATM example as proof of concept.     

A multi-agent knowledge model for SMEs mechatronic supply chains

The main concern of this research work is to analyse and model supply chains (SCs) in the particular context of small and medium enterprises (SMEs) in the field of mechatronic. The study is based on the analysis of the organisational features, the actors?? behaviour, and performance considerations. The development of the model relies on an iterative framework that progressively integrates different aspects into the model. This framework is the ArchMDE process, which is based on MDE (Model Driven Engineering). A major feature of this work lies in its contribution to two different areas of research. The first contribution of the work is to propose a generic metamodel for SCs. Based on a literature review, an incremental framework is proposed for the modelling of SCs in terms of concepts, structure and relationships. The application of the framework to the studied context is described and its result is a domain-metamodel for SCs. The second contribution of this work lies in the formalisation of the dynamic behaviour of the concepts in the metamodel. This formalisation is based on the multi-agent approach. An agentification of the metamodel is thus drawn, thanks to the natural links between multiagent theory and SC reality. This step leads to an agentified-domain-metamodel which also includes the monitoring of the SC and synchronisation protocols. By adding relationships and dynamic behavior aspects, we obtain a metamodel of the domain that can be implemented, with its static and dynamic aspects. To validate this model, an industrial case study is detailed and has been instantiated and encoded in JAVA.     

Reusable model transformations

Model transformations written for an input metamodel may often apply to other metamodels that share similar concepts. For example, a transformation written to refactor Java models can be applicable to refactoring UML class diagrams as both languages share concepts such as classes, methods, attributes, and inheritance. Deriving motivation from this example, we present an approach to make model transformations reusable such that they function correctly across several similar metamodels. Our approach relies on these principal steps: (1) We analyze a transformation to obtain an effective subset of used concepts. We prune the input metamodel of the transformation to obtain an effective input metamodel containing the effective subset. The effective input metamodel represents the true input domain of transformation. (2) We adapt a target input metamodel by weaving it with aspects such as properties derived from the effective input metamodel. This adaptation makes the target metamodel a subtype of the effective input metamodel. The subtype property ensures that the transformation can process models conforming to the target input metamodel without any change in the transformation itself. We validate our approach by adapting well known refactoring transformations (Encapsulate Field, Move Method, and Pull Up Method) written for an in-house domain-specific modeling language (DSML) to three different industry standard metamodels (Java, MOF, and UML).     

The whole-part relationship in object modelling: a definition in cOlOr

In object models built according to popular object-oriented formalisms, the commonest relationship types (excluding inheritance) are the structural relationships of association and of whole-part (often called aggregation). This last type is well known to have no accurately prescribed semantics. Here, some of the aggregation semantics frequently presented in the literature and sometimes supported in current object-oriented modelling languages, especially UML, are analysed and criticised. Because of defects, the use of a modelling notation based on these aggregation semantics is dubious and limited. Moreover, many properties are candidates for characterising the whole-part relationship provided that no redundancy and no inconsistency exist between them. A framework known as cOlOr is then offered by means of a metamodel in which the Whole-Part metatype inherits from the Structural-Relationship metatype. Defining a specific aggregation semantics leads then, first, within cOlOr, to the creation of a subtype of the Whole-Part metatype. Next, the behaviour of this last type is extended and/or restricted in using a constraint-based approach. Such a process is developed particularly for considering Composition in UML and Aggregation in OML more formally, as well as for dealing with domain-dependent aggregation semantics. Since a non-negligible feature of cOlOr is the availability of a C++ library that implements the proposed metamodel, some implementation concerns are also briefly discussed.     

Using UML Action Semantics for model execution and transformation

The Unified Modelling Language (UML) lacks precise and formal foundations and semantics for several modeling constructs, such as transition guards or method bodies. These semantic discrepancies and loopholes prevent executability, making early testing and validation out of reach of UML tools. Furthermore, the semantic gap from high-level UML concepts to low-level programming constructs found in traditional object-oriented language prevents the development of efficient code generators.The recent Action Semantics (AS) proposal tackles these problems by extending the UML with yet another formalism for describing behavior, but with a strong emphasis on dynamic semantics. This formalism provides both, a metamodel integrated into the UML metamodel, and a model of execution for these statements. As a future OMG standard, the AS eases the move to tool interoperability, and allows for executable modeling and simulation.We explore in this paper a specificity of the AS: its applicability to the UML metamodel, itself a UML model. We show how this approach paves the way for powerful metaprogramming for model transformation. Furthermore, the overhead for designers is minimal, as mappings from usual object-oriented languages to the AS will be standardized.     

Using UML/MARTE to support performance tuning and stress testing in real-time systems

Real-time embedded systems (RTESs) operating in safety-critical domains have to satisfy strict performance requirements in terms of task deadlines, response time, and CPU usage. Two of the main factors affecting the satisfaction of these requirements are the configuration parameters regulating how the system interacts with hardware devices, and the external events triggering the system tasks. In particular, it is necessary to carefully tune the parameters in order to ensure a satisfactory trade-off between responsiveness and usage of computational resources, and also to stress test the system with worst-case inputs likely to violate the requirements. Performance tuning and stress testing are usually manual, time-consuming, and error-prone processes, because the system parameters and input values range in a large domain, and their impact over performance is hard to predict without executing the system. In this paper, we provide an approach, based on UML/MARTE, to support the generation of system configurations predicted to achieve a satisfactory trade-off between response time and CPU usage, and stress test cases that push the system tasks to violate their deadlines. First, we devise a conceptual model that specifies the abstractions required for analyzing task deadlines, response time, and CPU usage, and provide a mapping between these abstractions and UML/MARTE. Then, we prune the UML/MARTE metamodel to only contain a purpose-specific subset of entities needed to support performance tuning and stress testing. The pruned version is a supertype of UML/MARTE, which ensures that all instances of the pruned metamodel are also instances of UML/MARTE. Finally, we cast the generation of configurations and stress test cases as two constrained optimization problems (COPs) over our conceptual model. The input data for these COPs in automatically generated via a model-to-text (M2T) transformation from models specified in the pruned UML/MARTE metamodel to the Optimization Programming Language. We validate our approach in a safety-critical RTES from the maritime and energy domain, showing that (1) our conceptual model can be applied in an industrial setting with reasonable effort, and (2) the optimization problems effectively identify configurations predicted to minimize response time and CPU usage, and stress test cases that maximize deadline misses. Based on our experience, we highlight challenges and potential issues to be aware of when using UML/MARTE to support performance tuning and stress testing in an industrial context.     

Modelling and querying geographical data warehouses

A number of proposals for integrating geographical (Geographical Information Systems—GIS) and multidimensional (data warehouse—DW and online analytical processing—OLAP) processing are found in the database literature. However, most of the current approaches do not take into account the use of a GDW (geographical data warehouse) metamodel or query language to make available the simultaneous specification of multidimensional and spatial operators. To address this, this paper discusses the UML class diagram of a GDW metamodel and proposes its formal specifications. We then present a formal metamodel for a geographical data cube and propose the Geographical Multidimensional Query Language (GeoMDQL) as well. GeoMDQL is based on well-known standards such as the MultiDimensional eXpressions (MDX) language and OGC simple features specification for SQL and has been specifically defined for spatial OLAP environments based on a GDW. We also present the GeoMDQL syntax and a discussion regarding the taxonomy of GeoMDQL query types. Additionally, aspects related to the GeoMDQL architecture implementation are described, along with a case study involving the Brazilian public healthcare system in order to illustrate the proposed query language.     

Metamodeling generalization and other directed relationships in UML

ContextGeneralization is a fundamental relationship in object orientation and in the UML (Unified Modeling Language). The generalization relationship is represented in the UML metamodel as a “directed relationship”.ObjectiveBeing a directed relationship corresponds to the nature of generalization in the semantic domain of object orientation: a relationship that is directed from the subclass to the superclass. However, we claim that the particular form this relationship adopts in the metamodel is erroneous, which entails a series of inconveniencies for model manipulation tools that try to adhere to the UML specification. Moreover, we think that this error could be due to a misinterpretation of the relationships between metamodeling levels in the UML: represented reality (M0), model (M1) and metamodel (M2). This problem also affects other directed relationships: Dependency and its various subtypes, Include and Extend between use cases, and others.MethodWe analyze the features of the generalization relationship in various domains and how it has been metamodeled in UML. We examine the problems, both theoretical and technological, posed by the UML metamodel of generalization. We then compare it with the metamodel of other directed relationships.ResultsWe arrive at the conclusion that the metamodel of all directed relationships could be improved. Namely, we claim that, at level M2, the metamodel should not contain any one-way meta-associations: all meta-associations should be two-way, both for practical and theoretical reasons.ConclusionsThe rationale for our main claim can be summarized as follows: connected graphical symbols do know each other, and the goal of a metamodel is to specify the syntactic properties of a language, ergo meta-associations must be two-way. This, of course, does not preclude at all the use of one-way associations at the user model level (M1).     

DMS系统图形绘制软件架构模型的研究与设计

文章简单介绍了文中涉及的统一建模语言UML的概念,论述了配电自动化系统中图形绘制软件主要的功能需求和非功能需求,通过对这些需求的研究和分析,提出了一个基于模型-视图-控制设计模式、符合面向对象思想的图形绘制软件架构模型,详细分析了组成该模型的类,用UML的类图和时序图描述了模型的静态和动态架构,以开发原型系统的方式验证了该模型的合理性和可用性。     

基于同态映射的从UML导出可综合Verilog算法

UML建模因其可显著提高开发效率和代码质量已经成为软件开发领域的一大热点，而硬件设计的日益复杂性也要求我们在更高层次抽象上分析和验证系统行为，故更精细的系统级建模方法变得日趋重要。本文构建了UML元模型与可综合Verilog间的同态映射，定义了一个从UML模型子集导出可综合Verilog描述的算法，为UML模型对于建模硬件系统提供了形式化的语义，从而使运用UML进行硬件系统级建模和系统级上验证系统性能和功能正确性成为可能。     

Extending the Unified Modeling Language for ontology development

There is rapidly growing momentum for web enabled agents that reason about and dynamically integrate the appropriate knowledge and services at run-time. The dynamic integration of knowledge and services depends on the existence of explicit declarative semantic models (ontologies). We have been building tools for ontology development based on the Unified Modeling Language (UML). This allows the many mature UML tools, models and expertise to be applied to knowledge representation systems, not only for visualizing complex ontologies but also for managing the ontology development process. UML has many features, such as profiles, global modularity and extension mechanisms that are not generally available in most ontology languages. However, ontology languages have some features that UML does not support. Our paper identifies the similarities and differences (with examples) between UML and the ontology languages RDF and DAML+OIL. To reconcile these differences, we propose a modification to the UML metamodel to address some of the most problematic differences. One of these is the ontological concept variously called a property, relation or predicate. This notion corresponds to the UML concepts of association and attribute. In ontology languages properties are first-class modeling elements, but UML associations and attributes are not first-class. Our proposal is backward-compatible with existing UML models while enhancing its viability for ontology modeling. While we have focused on RDF and DAML+OIL in our research and development activities, the same issues apply to many of the knowledge representation languages. This is especially the case for semantic network and concept graph approaches to knowledge representations. Initial sbmission: 16 February 2002 / Revised submission: 15 October 2002 Published online: 2 December 2002     

Towards a Megamodel to Model Software Evolution Through Transformations

Model Driven Engineering is a promizing approach that could lead to the emergence of a new paradigm for software evolution, namely Model Driven Software Evolution. Models, Metamodels and Transformations are the cornerstones of this approach. Combining these concepts leads to very complex structures which revealed to be very difficult to understand especially when different technological spaces are considered such as XMLWare (the technology based on XML), Grammarware and BNF, Modelware and UML, Dataware and SQL, etc. The concepts of model, metamodel and transformation are usually ill-defined in industrial standards like the MDA or XML. This paper provides a conceptual framework, called a megamodel, that aims at modelling large-scale software evolution processes. Such processes are modeled as graphs of systems linked with well-defined set of relations such as RepresentationOf (μ), ConformsTo (χ) and IsTransformedIn (τ).     

Are use case and class diagrams complementary in requirements analysis? An experimental study on use case and class diagrams in UML

Despite the status of united modeling language (UML) as the de facto standard for object oriented modeling, it has received controversial reviews. The most controversial diagram in UML is the use case diagram. Some practitioners claim that use case diagrams are not valuable in requirements analysis and some have even argued that use case diagrams should not be part of UML. This research examined the values of use case diagram in interpreting requirements when use case diagrams are used in conjunction with class diagrams. In other words, the study investigated the possible synergetic values and relationships between the use case and class diagrams in the context of requirements analysis. This study used theories from cognitive psychology as its theoretical and conceptual foundation. The data collection utilized the verbal protocol technique in which subjects were asked to think aloud as they interpreted the use case and class diagrams. The results show that the use case diagrams were more completely interpreted than the class diagrams. The presence or absence of one diagram when interpreting another diagram had no effect on the outcome of the interpretation. From the results, we argue that the use case diagrams and class diagrams depict different aspects of the problem domain, they have very little overlap in the information captured, and both are necessary in requirements analysis.