André Marburger

Graph-based tools for re-engineering

Maintenance of legacy systems is a challenging task. Often, only the source code is still available, while design or requirements documents have been lost or have not been kept up-to-date with the actual implementation. In particular, this applies to many business applications which are run on a mainframe computer and are written in COBOL. Many companies are confronted with the difficult task of migrating these systems to a client/server architecture with clients running on PCs and servers running on the mainframe. REforDI (REengineering for DIstribution) is a graph-based environment supporting this task. REforDI provides integrated code analysis, re-design, and code transformation for COBOL applications. To prepare the application for distribution, REforDI assists in the transition to an object-based architecture, according to which the source code is subsequently transformed into Object COBOL. Internally, REforDI makes heavy use of generators to reduce the implementation effort and thus to enhance adaptability. In particular, graph-based tools for re-engineering are generated from a formal specification which is based on programmed graph transformations.

Tools for understanding the behavior of telecommunication systems

Many methods and tools for the reengineering of software systems have been developed so far However, the domain-specific requirements of telecommunication Systems have not been addressed sufficiently. These systems are designed in a process- rather than in a data-centered way. Furthermore, analyzing and visualizing dynamic behavior is a key to system understanding. In this paper, we report on tools for the reengineering of telecommunication systems which we have developed in close cooperation with an industrial partner These tools are based on a variety of techniques for understanding behavior such as visualization of link chains, recovery of state diagrams from the source code, and visualization of traces by different kinds of diagrams. Tool support has been developed step by step in response to the requirements and questions stated by telecommunication experts at Ericsson Eurolab Germany.

The use of layers and planes for architectural design of communication systems

Do we have the right set of concepts for modeling and describing distributed real-time systems in software engineering? Languages like ROOM (Real-time Object-Oriented Modeling) and UML-RT (Unified Modeling Language for Real-Time) offer some basic concepts; however, system engineers of the application domain (e.g. in telecommunications) work with a variety of concepts which do not have a corresponding counterpart in software engineering. There seems to be some potential for transfer. This report explores the power of a well-known concept in telecommunications, the service access point (SAP). SAPs not only prove to be more powerful than layering is, but they even subsume the concept of planes, which are almost unknown in software engineering. SAPs turn out to be a basic modeling construct, which allows us to describe in a precise manner any communication architecture that is structured in layers and planes. In this paper, it is shown that a few improvements to ROOM/UML-RT can make the full power of SAPs available to the object-oriented design of distributed real-time systems.

Graph-Based Reengineering of Telecommunication Systems

The E-CARES project addresses the reengineering of large and complex telecommunication systems. Within this project, graph-based reengineering tools are being developed which support not only the understanding of the static structure of the software system under study. In addition, they support the analysis and visualization of its dynamic behavior. The E-CARES prototype is based a programmed graph rewriting system from which the underlying application logic is generated. Furthermore, it makes use of a configurable framework for building the user interface. By means of reuse and generators, the effort of implementing the E-CARES prototype is reduced considerably.

Behavioral Analysis of Telecommunication Systems by Graph Transformations

The E-CARES project addresses the reengineering of large and complex telecommunication systems. Within this project, graph-based reengineering tools are being developed which support not only the understanding of the static structure of the software system under study. In addition, they support the analysis and visualization of its dynamic behavior. The E-CARES prototype is based on a programmed graph rewriting system from which the underlying application logic is generated. Furthermore, it makes use of a configurable framework for building the user interface. In this paper, we report on our findings regarding feasibility, complexity, and suitability of developing tool support for the behavioral analysis of telecommunication systems by means of graph rewriting systems.

Graph-based structural analysis for telecommunication systems

Many methods and tools for the reengineering of software systems have been developed so far. However, the domain-specific requirements of telecommunication systems have not been addressed sufficiently. The E-CARES project is dedicated to reverse engineering of complex legacy telecommunication systems by providing graph-based tools. With E-CARES, the software architecture of a telecommunication system is recovered in two steps. In the first step (program analysis), the source code is parsed to build a structure graph which uses the abstractions of the underlying programming language and describes the internals of program units (blocks) as well as their communication via exchange of signals. In the second step, a software architecture description is abstracted from the structure graph. The software architecture is described in ROOM, a real-time object-oriented modeling language for embedded systems design. Both program analysis and architecture recovery are based on graphs and graph transformations. In both steps, domain-specific knowledge -- referred to as methods of use -- is exploited which refers to the ways how language constructs are used to realize processing concepts of telecommunication systems.

E-CARES - Telecommunication Re- and Reverse Engineering Tools

The E-CARES project addresses the reengineering of large and complex telecommunication systems. Within this project, graph-based reengineering tools are being developed which support not only the understanding of the static structure of the software system under study. In addition, they support the analysis and visualization of its dynamic behavior. The E-CARES prototype is based on a programmed graph rewriting system from which the underlying application logic is generated. Furthermore, it makes use of a configurable framework for building the user interface. In this demo, we show by example how the different tools within the prototype work and how the analysis results are represented to the user.