The success of enterprise system (ES), to a great extent, depends on users' learning outcomes, which in turn, are determined by motivation and cognitive ability. Given the central role played by motivation, this paper applies the goal-setting theory and the expectancy theory to investigate the antecedents and consequence of users' commitment to the goal of learning how to effectively apply ES. In particular, we focus on the effects of workplace environmental factors (i.e., work overload, leader member exchange and IT support) on goal commitment, which leads to user competence. In addition to the direct, main effects, we also explore how IT support and socialization tactics moderate the relationships between antecedents and goal commitment and between goal commitment and user competence, respectively. The research model is largely supported by data collected in a two-wave survey. Theoretical contribution and implications of this study are discussed.