This paper investigates the effects of applying agile software development practices within Systems Engineering projects. In particular it should be found out whether agile methods are able to mitigate negative effects of requirement changes on project performance. Customer satisfaction is chosen as performance factor. 72 system developing companies are surveyed that develop products consisting of hard- and software. Since agile methods have been successfully applied within software development our hypothesis is that they could also be successfully applied within Systems Engineering. Our study focuses on 6 specific agile practices and their ability to improve customer satisfaction in complex hard- and software projects. It is shown that some of them have a positive effect on customer satisfaction but we do not find evidence for others.