Christoph Brandt

Security and Consistency of IT and Business Models at Credit Suisse Realized by Graph Constraints, Transformation and Integration Using Algebraic Graph Theory

This paper shows typical security and consistency challenges regarding the models of the business and the IT universe of the dynamic service-, process- and rule-based environment at Credit Suisse. It presents a theoretical solution for enterprise engineering that is implementable, and fits smoothly with the daily needs and constraints of the people in the scenario. It further enables decentralized modeling based on cognitive and mathematical or logical concepts. Normative aspects of the models are analyzed by graph constraint checks, while consistency is checked and ensured by model integration and transformation. To cope with theoretical and practical necessities, the presented solution is kept sound and usable as well as extensible and scalable. All techniques are based on one theoretical framework: algebraic graph theory. Therefore, the techniques are compatible with each other.

Modeling and reconfiguration of critical business processes for the purpose of a Business Continuity Management respecting security, risk and compliance requirements at Credit Suisse using algebraic graph transformation

Critical business processes can fail. Therefore, continuity processes are needed as backup solutions. At the same time business processes are required to comply with security, risk and compliance requirements. In the context discussed here, they should be modeled in a decentralized, local and declarative way, including methodological support by tools. By discussing a simplified loan granting process in the context of a Business Continuity Management System at Credit Suisse, we show how algebraic graph transformation can contribute a methodologically sound solution being compatible with all these requirements in a coherent way. As a consequence significant benefits of automation and quality can be realized. The presented contribution is theoretically sound and implementable by the people in the field.

How far can enterprise modeling for banking be supported by graph transformation

This keynote paper presents results coming out of an ongoing research project between Credit Suisse Luxembourg and the University of Luxembourg. It presents an approach that shows good potential to address security, risk and compliance issues the bank has in its daily business by the use of integrated organizational models build up by enterprise modeling activities. Such organizational models are intended to serve to describe, evaluate, automate, monitor and control as well as to develop an organization respecting given organizational security, risk and compliance side-constraints. Based on the empirical scenario at Credit Suisse, real-world requirements towards a modeling framework as well as the modeling process are developed. Graph Transformation techniques are proposed as formal framework for this purpose and they are evaluated in the sense of how far they can support the identified enterprise modeling activities in the context of the new enterprise modeling framework.

Propagation of Constraints along Model Transformations Based on Triple Graph Grammars

Model transformations based on triple graph grammars (TGGs) have been applied in several practical case studies and they convince by their intuitive and descriptive way of specifying bidirectional model transformations. Moreover, fundamental properties have been extensively studied including syntactical correctness, completeness, termination and functional behaviour. But up to now, it is an open problem how domain specific properties that are valid for a source model can be preserved along model transformations such that the transformed properties are valid for the derived target model. In this paper, we analyse in the framework of TGGs how to propagate constraints from a source model to an integrated and target model such that, whenever the source model satisfies the source constraint also the integrated and target model satisfy the corresponding integrated and target constraint. In our main new results we show under which conditions this is possible. The case study shows how this result is successfully applied for the propagation of security constraints in enterprise modelling between business and IT models.

Domain-specific modelling languages with algebraic graph transformations on RDF

Domain-specific modelling langugages (DSMLs), which are tailored to the requirements of their users, can significantly increase the acceptance of formal (or at least semi-formal) modelling in scenarios where informal drawings and natural language descriptions are predominant today. We show in this paper how the Resource Description Framework (RDF), which is a standard for the fundamental data structures of the Semantic Web, and algebraic graph transformations on these data structures can be used to realise the abstract syntax of such DSMLs. We examine a small DSML for IT infrastructures as an application scenario. From this scenario, we derive distributed modelling, evolution of language definitions, migration of legacy models and integration of modelling languages as key requirements for a DSML framework. RDF and transformation rules are then used to provide a solution, which meets these requirements, where all kinds of modifications-from simple editing steps via model migration to language integration--are realised by the single, uniform formalism of algebraic graph transformation.

How to Modify on the Semantic Web

In this paper, we show how formal methods of algebraic graph transformation can be made available in the technological environment of the Semantic Web. This new and promising approach allows to model and formulate transformation operations on a high level of abstraction. To demonstrate its feasibility, we develop a small book shop case study. We show how some of the necessary modification operations in this settings can be realised by the proposed SPARQL/Update language and by our rule-based graph transformation approach. In a comparison, we highlight the main differences between these two approaches. The most important benefit of our rule-based transformation approach is that it facilitates to move from application engineering to rule engineering and thereby support generic solutions, which lower the maintenance efforts by supporting the declarative specification of modification operations.