Schools address students' educational needs by delivering a range of traditional and innovative programs. Selecting, implementing, and sustaining a new program is a school improvement initiative. Despite investments of (often) substantial resources, many such programs have relatively short school lives. Effective educational initiatives need to survive in order to continue to deliver personal, social, and economic benefits. However, practical guidance for sustainable implementation of new initiatives in school settings is relatively lacking. Drawing from literature and interviews with 70 school leaders and teachers, we created and delivered to 10 educational sites a self-assessment site improvement tool. Principal components analysis identified 20 components, and feedback from sites indicated the practical usefulness of the tool. Adopting a systems perspective with explicit attention to interactions between goals, processes, and emerging outcomes has the potential to generate more thorough consideration of the range of components that influence sustained program implementation leading to site improvement.