The present study entails the literature in critical success factors (Daniel, 1961; Rockart, 1979; Thierauf, 1982; Pinto & Slevin, 1987; Wijn et.al, 1996) namely for ERP implementation (Sarkar et.al, 2003; Jaideep et.al, 2005, Koh et.al, 2011) and the components of user satisfaction (Doll & Torkzadeh, 1988). The primary purpose of this research is to explain the critical factors for successful ERP implementation in United Nations type of organization and set up a grounded research approach that aims to identify and investigate the relationship between the components of user satisfaction with the goal to propose a model that explains the success factors and relevant relationships between information technology usage, information characteristics and business processes. A three dimension (triangulation) approach consisting of grounded research, a quantitative survey methodology and qualitative semi-structured interviews was used to collect information and data from a United Nations agency in Montreal, Canada. The data for the research was taken over a period of 6 months, studying documents of project implementation, discussions, meetings, observations, a survey with 101 responses and interviewing 10 senior management officials. Exploratory factor analysis (EFA) was performed to identify the relevant factors critical to the success of ERP implementation. A correlation analysis was done to understand the relationship between the components of user satisfaction. Structural equation modelling (SEM) technique was then used to extract a model that explains ERP implementation. Finally, qualitative information were examined in light of the findings to complete our investigation loop. The findings along with the theoretical and practical significance of the research are discussed.