Issues of workflow systems adaptability and evolution capability are discussed from two perspectives, namely design and evolution of workflow systems from a continuous software engineering perspective as well as redesign and runtime on-the-fly modifications of workflow models from an application perspective. Special attention is paid to a suitable infrastructure support for designing more configurable and adaptive workflow systems. A new workflow language, called Higher-Order Object Nets (HOON), is introduced. The intended uses of HOON are, on one side, to directly describe real-world business processes, and on the other side, to serve as a build-time composition model and a run-time overall control skeleton of the underlying software components that support individual business activities. On the basis of HOON and CORBA, a layered, framework-based and generic system architecture is presented.

Issues concerning computer-aided software engineering (CASE) are briefly described. Particular attention is given to the integration of independently developed tools, the use of standard and public tool interfaces for purposes of integration, the development of a reference model, customization techniques, and formal process models.>

A modularity concept for structuring large software systems is presented. The concept enforces an extreme modularity discipline that goes considerably beyond the one found in modern programming languages such as MODULA-2 or Ada. The concept is meant to be used to tightly control side effects in the execution of systems that are constructed of independently developed modules. A family of specification languages is introduced whose members are all based on the modularity concept and thus support the uniform monolinguistic specification of software systems at all development stages. The languages have been defined to enable matching informal, semiformal, and formal specifications and thus to make formal specification of modular systems practicable. The construction of large software systems as interconnections of modules is shown to lead to manageable system structures and to new degrees of freedom in the structuring of the software development process. The suitability of the modularity concept has been evaluated in a large software project for the development of a database management system. The concept and specification languages are explained with the aid of sample specifications.

This tutorial focuses on the application of sof twere engineering techniques for the development of data base systems. It is aimed to explain a key concept in software engineering - the module or abstract data type concept - and to demonstrate its usefulness in data base system structuring and design. The concept is shown to provide a basis for the development of a uniform framework -called D-graph- for the structuring of the data base, its conceptual description and of the data base management system.