ConcurTaskTrees (CTT) and its supporting environment (CTTE) have been widely used for a significant period of time. However, users have expressed various concerns regarding their usability. In this paper, we present the modifications made so as to provide more effective support. In particular, the environment has been enhanced in order to make it more suitable for designing real-world applications, including improved support for task model editing and early prototype generation. We also report on two evaluation tests that provided useful feedback in order to decide how to improve the environment.