This paper addresses two aspects of integrating mathematics education with engineering education that may address persistence of engineering majors (and STEM majors more broadly): an emphasis on modeling as a vehicle for more authentic learning activity (Niss et al. 2007), and the need for measures that can support academic units' efforts to collect local data about student attainment of program goals. In this paper, we contribute: (1) a measure for modeling self-efficacy and its corresponding design process; (2) a measure for modeling competency and its corresponding design process; and (3) a preliminary analysis of the relationship between modeling competency and self-efficacy. We argue that such instruments address a genuine need of engineering departments (as well as STEM education researchers) to have a means for collecting local data on students' modeling self-efficacy and competency.