The Every Student Succeeds Act of 2015 grants states and districts the flexibility to use multiple measures to assess school performance and strategically manage public schools for improvement in the United States. However, there is a lack of systematic, evidence-based guidance for practitioners on how to interpret the complex relationships between these multiple measures. Drawing on the organizational management literature on the multidimensionality of organizational effectiveness, along with longitudinal data from Washington State, we illustrate the multidimensionality of school performance and different measurement properties of school performance data. We also find that schools that are higher performing in terms of students' average scale scores and average growth percentiles in some cases have larger disparities in these same measures between historically underserved students of color and their peers than lower performing schools do. Moreover, these performance measures have time-series properties. The complexity of school performance measurement systems calls for continuous support for local educators to appropriately use school performance data to promote student success.