This paper relies on the ideas that underpin the scholarly school of developing pedagogical systems to assess the degree to which instructors are prepared to manage the development of the school they teach at. The authors propose a structural/functional model for instructor preparedness to be the subject of innovation activity, provide a relevant methodology for it, and describe the content and findings of their empirical substantiation of it. The study identifies instructor groups with a high, medium, and low degree of preparedness to manage innovation activity in a school and establishes statistically significant differences between them in terms of the degree to which the motivational, cognitive, technological, and organizational components of preparedness have been formed. The authors come up with a proof that the instructor's preparedness to be the subject of innovation activity depends on the degree of his/her preparedness to fulfill particular duties in managing this activity. The paper identifies specific factors behind the differences between instructors in this characteristic and determines the degree of their impact. The authors establish a close link between the instructor's preparedness to be the subject of innovation activity and his/her actual participation in resolving objectives in managing the school's development. The use of the authors' methodology for assessing instructors' preparedness to manage innovation activity in a school could help determine specific factors affecting it and develop individual trajectories of increase in their innovation competence, as well as facilitate their productive involvement in the process of working out the school development program.