No Child Left Behind has increased data collection and reporting, the development of data systems, and interest in using data for decision-making in schools and classrooms. Ends-driven decision making has become common educational practice, where the ends justify the means at all costs, and short-term results trump longer-term outcomes and the bigger educational picture. From narrowing the curriculum, to the "bubble kids" phenomenon of teachers focusing on students who are near the cut-off for passing state achievement tests, to students getting paid for passing scores, ends-driven decision making has become part of schooling and exemplifies a current form of data-based decision making. However, if people chose to apply a systems approach to data-based decision making in schools, an approach that can help leaders view schools as complex living systems, they can increase the positive potential of data-based decision making to help educators make reasonable decisions about "means". The purpose of this article is to describe, using Toyota Motor Corporation as an example, how applying a systems approach to data-based decision making in schools can support school leaders and educators in making decisions about means--the internal operations of the school or classroom--and promote student and school success.