Apart from functionality, various software quality attributes such as reliability, performance and security may be required for software systems. Quality attributes are especially important considerations during the design phase of software development because different designs lead to the implementations exhibiting different qualities. If we can analyze a design to predict how well the implementation of the design will meet quality attributes, we can significantly save the total development cost and time. Therefore in the past m any analysis methods have been proposed but either they are hard-to-learn and use or, in the case of simulation-based analysis, functionality concerns and quality analysis concerns were intermingled in the design as well as in the implementation thereby making development and maintenance more complicated. In this thesis, we propose a simulation-based design phase analysis method based on aspect-oriented programming. In our method, quality analysis aspects remain separate from functionality aspect in the design model and the implementation code for simulation is automatically obtained by injecting quality analysis code into the skeleton code generated from the design-level functionality model. Our method has advantages over the conventional approach in reducing both the development cost and the maintenance cost.