Web information systems (WIS) augment classical information systems by modern Web technologies. They require at the same time a careful development and support for the interaction or story spaces beside the classical support for the working space of users. These dimensions complicate the system development process. This paper shows how classical advanced methodologies can be carefully enhanced. We evaluated the Co-Design approach to information systems development according to the ISO/IEC 15504 Framework for Process Assessment (SPICE) and derived the potential and deficiencies of this approach. This evaluation has been used for a managed Co-Design methodology. Since WIS constantly change and evolve the development process never ends. We develop as a solution an optimization procedure and a runtime environment for the Co-Design approach that allows to cope with such changes, with evolution and extension of WIS and that demonstrates the new system facilities whenever a change is mastered.