In undergraduate thesis process, a lecturer can guide one or several students with similar topics and methods. Therefore, a collaborative learning system can facilitate guidance of a lecturer and his/her students. In this paper we designed a software architecture of collaborative learning system using Aspect Oriented Architecture Description Language (AO-ADL). The architectural design was implemented using MVC concept. In order to design the software architecture, we identified and analyzed three non functional requirements: reliability, availability, usability. The architectural design was evaluated using the Architecture Tradeoff Analysis Method (ATAM). The evaluation results shows that usability has a tradeoff with the functionality, and usability has a tradeoff with modifiability. The testing of the system was the distribution of questionnaires to users and black box testing.