Several studies have investigated the success of ASP from various perspectives. This study, thus, investigated factors affecting ASP effectiveness in various literature relevant ASP and outsourcing. By applying the basic ideas of the IS success model, this study proposes a research model of the factors affecting the success of ASP, in term of internal factors(Top Management Involvement, User Participation, Size of Organization, IS Maturity) and Reliability factors(Transaction Reliability, After-Sale Reliability, System Reliability, Security). The proposed model is expected to provide a guideline to researchers and practitioners extend their understanding of the success factors of the ASP effectiveness.