Simple e-commerce applications are replaced by e-business applications that are more complex and provide much greater functionality. In such applications not only the customer-company relationship has an electronic form, but also the internal business processes of the company are realized by computers. Accordingly the whole information storage, processing and retrival of the company is done electronically, in form as a web application that allows a much tighter integration of different business areas. Quality of Service (QoS) was a crucial property of e-commerce application. It becomes even more important in e-business applications, since the operation of the company depends on it. QoS is characterized by: reliability, availability, proper behaviour, sufficient performance. What the user observes as Quality of Service depends not only on the quality of software implementation but on the behavior of the system in critical, unexpected cases. Systems are called robust if they meet the above requirements. Design and implementation must be made very carefully to reach robustness. The aim of the project is to develop a new technology and to test it in form of an experiment. The technology should allow the development of robust e-business applications. As such the project wants: to go beyond simple e-commerce applications, to provide a methodology to extend the scope of the UML language from software design to model the logical, qualitative and quantitative behaviour of the whole system, to give a solution to cope with the low quality of service originating from the unreliability and failures of the heterogenous application environment, to develop an efficient and reliable development method for the e-business systems of small- and medium sized enterprices, to make an experiment to test and present the above solutions.