What is one of the notable contributions of Daniel Craig McCallum to management systems?

The notable contribution of Daniel Craig McCallum to management systems is the creation of organizational charts. This development was significant as it provided a visual representation of the hierarchy and structure within organizations, clarifying roles, responsibilities, and reporting relationships. By introducing organizational charts, McCallum improved the efficiency of management practices by making it easier to understand how different functions and departments interact, thereby facilitating better communication and collaboration within enterprises. This innovation laid the groundwork for modern organizational design and management practices that emphasize clarity and visibility in workplace structures.