Christian Soltenborn

Analysis of UML activities using dynamic meta modeling

Dynamic Meta Modeling (DMM) is a universal approach to defining semantics for languages syntactically grounded on meta models. DMM has been designed with the aim of getting highly understandable yet precise semantic models which in particular allow for a formal analysis. In this paper, we exemplify this by showing how DMM can be used to give a semantics to and define an associated analysis technique for UML Activities.

Showing full semantics preservation in model transformation: a comparison of techniques

Model transformation is a prime technique in modern, model-driven software design. One of the most challenging issues is to show that the semantics of the models is not affected by the transformation. So far, there is hardly any research into this issue, in particular in those cases where the source and target languages are different. In this paper, we are using two different state-of-the-art proof techniques (explicit bisimulation construction versus borrowed contexts) to show bisimilarity preservation of a given model transformation between two simple (self-defined) languages, both of which are equipped with a graph transformation-based operational semantics. The contrast between these proof techniques is interesting because they are based on different model transformation strategies: triple graph grammars versus in situ transformation. We proceed to compare the proofs and discuss scalability to a more realistic setting.

From UML Activities to TAAL - Towards Behaviour-Preserving Model Transformations

Model transformations support a model-driven design by providing an automatic translation of abstract models into more concrete ones, and eventually program code. Crucial to a successful application of model transformations is their correctness, in the sense that the meaning (semantics) of the models is preserved. This is especially important if the models not only describe the structure but also the intended behaviourof the systems. Reasoning about and showing correctness is, however, often impossible as the source and target models typically lack a precise definition of their semantics. In this paper, we take a first step towards provably correct behavioural model transformations. In particular, we develop transformations from UML Activities (which are visual models) to programs in TAAL, which is a textual Java-like programming language. Both languages come equipped with formal behavioural semantics, which, moreover, have the same semantic domain. This sets the stage for showing correctness, which in this case comes down to showing that the behaviour of every (well-formed) UML Activity coincides with that of the corresponding TAAL program, in a well-defined sense.

Assuring Consistency of Business Process Models and Web Services Using Visual Contracts

Business process models describe workflows by a set of actions together with their ordering. When implementing business processes within a service-oriented architecture, these actions are mapped to existing IT (web) services, which are then to be executed in the order specified by the business process. However, the execution of a web service can require certain preconditions to be fulfilled. These might not hold at the time of execution specified in the business process model: it can be inconsistent with the web service specification. In this paper we propose a technique for checking consistency of process models with web service specifications. To this end, both are equipped with a formal semantics (in terms of graph transformations). We show how to use an existing model checker for graph transformation systems to carry out the consistency check.

Extending DMM behavior specifications for visual execution and debugging

Dynamic Meta Modeling (DMM) is a visual semantics specification technique targeted at behavioral languages equipped with a metamodel defining the languages abstract syntax. Given a model and a DMM specification, a transition system can be computed which represents the semantics of that model. It allows for the investigation of the models behavior, e.g. for the sake of understanding the models semantics or to verify that certain requirements are fulfilled. However, due to a number of reasons such as tooling and the size of the resulting transition systems, the manual inspection of the resulting transition system is cumbersome. One solution would be a visualization of the models behavior using animated concrete syntax. In this paper, we show how we have enhanced DMM such that visual execution and debugging can be added to a language in a simple manner.

Towards Test-Driven Semantics Specification

Behavioral models are getting more and more important within the software development cycle. To get the most use out of them, their behavior should be defined formally. As a result, many approaches exist which aim at specifying formal semantics for behavioral languages (e.g., Dynamic Meta Modeling (DMM), Semantic Anchoring). Most of these approaches give rise to a formal semantics which can e.g. be used to check the quality of a particular language instance, for instance using model checking techniques. However, if the semantics specification itself contains errors, it is more or less useless, since one cannot rely on the analysis results. Therefore, the language engineer must make sure that the semantics he develops is of the highest quality possible. To help the language engineer to achieve that goal, we propose a test-driven semantics specification process: the semantics of the language under consideration is first informally demonstrated using example models, which will then be used as test cases during the actual semantics specification process. In this paper, we present this approach using the already mentioned specification language DMM.

QUAASY: QUality Assurance of Adaptive SYstems

The emerging approach to tackle the increasing complexity of todays software systems is the use of self-adaptation techniques. Modeling and implementing adaptivity features is a burdensome and error-prone task that potentially results in erroneous system models. As a consequence, quality analysis and assurance must be considered early in the development of self-adaptive systems. We propose a quality assurance approach for self-adaptive systems in terms of an integrated modeling and analysis approach, which helps identifying errors in modeled self-adaptive systems early in the design process. We employ a modeling language for self-adaptive systems including adaptation rules and formally define their semantics. Given the language and its formal semantics, we formulate quality properties, such as fairness of the specified adaptation rule system. These quality properties are verified using a model checking approach.

Improving reusability of dynamic meta modeling specifications with rule overriding

In this paper, we enhance DMM such that DMM rules can “override” other DMM rules, similar to a method being overridden in a subclass. We argue that this does not only have positive impact on reusability of DMM specifications, but also improves the intuitive understandability of DMM rules.

Unternehmensweit verstehen – unternehmensweit entwickeln: Von der Modellierungssprache zur Softwareentwicklungsmethode

ZusammenfassungSollen wir UML 1.4, UML 2.0 oder eine ganz andere Modellierungssprache für unsere Softwareentwicklung einsetzen? Der folgende Beitrag zeigt, dass bei der Festlegung einer unternehmensweiten Entwicklungsmethode nicht die Frage nach der Modellierungssprache im Vordergrund stehen sollte. Viel entscheidender für den Erfolg von Softwareentwicklungsprojekten in einem Unternehmen ist ein einheitliches Verständnis der Entwicklungskonzepte und -artefakte sowie ihrer Beziehungen untereinander. Eine Einigung über ein unternehmensweites Domänenmodell der Softwareentwicklungskonzepte sollte deshalb vor der Auswahl von Modellierungssprachen, eines konkreten Vorgehensmodells und geeigneter Werkzeuge erfolgen.

Using rule overriding to improve reusability and understandability of Dynamic Meta Modeling specifications

Dynamic Meta Modeling (DMM) is a visual semantics specification technique targeted at languages based on a metamodel. A DMM specification consists of a runtime metamodel and operational rules which describe how instances of the runtime metamodel change over time. A known deficiency of the DMM approach is that it does not support the refinement of a DMM specification, e.g., in the case of defining the semantics for a refined and extended domain-specific language (DSL). Up to now, DMM specifications could only be reused by adding or removing DMM rules. In this paper, we enhance DMM such that DMM rules can override other DMM rules, similar to a method being overridden in a subclass, and we show how rule overriding can be realized with the graph transformation tool GROOVE. We argue that rule overriding does not only have positive impact on reusability, but also improves the intuitive understandability of DMM semantics specifications.