Good software architecture is critically important for successful software development. The software architecture can be defined as a set of architectural design decisions. However, the effort for acquiring good software architecture currently lacks of interest and experience in architectural design decisions. For this reason, during acquiring good software architecture, it is difficult to evaluate the architectural designs and make changes to the architecture that is relevant for the required changes. Therefore, this paper proposes a model of architectural design decisions for making architectural design decisions more explicit. Based on the proposed model, this paper also proposes an integrated approach for acquiring good software architecture with respect to its requirements, which is called AQUA. Namely, the AQUA defines decisioncentric process of finding, evaluating, and changing the decisions. During the decision-centric process, the AQUA involves works of architectural evaluatio...