One large and quite interesting family of MAS applications is characterized (1) by their large scale in terms of number of agents and physical distribution, (2) by their very dynamic nature and (3) by their complex functional and non-functional requirements. This family includes a.o. manufacturing control, traffic control and web service coordination. BDI-based agent architectures have proven their usefulness in building MASs for complex systems - their explicit attention for coping with dynamic environments is one obvious explanation for this. For the family of applications mentioned above, the complexity of the software for the individual agents using traditional BDI-approaches, however, is overwhelming. In this paper, we present an innovative approach to BDI agents which alleviates agent complexity through so-called "delegate MASs", which use the environment and its resources to obtain BDI functionality. Delegate MASs consist of light-weight agents, which are issued either...