Volume 1 establishes the theoretical and methodological foundations of the Theory of Open Manufacturing (TOM), a modern manufacturing paradigm developed to address the limitations of traditional manufacturing theories in the digital era. The volume introduces the evolution of manufacturing theories, presents the principles and framework of TOM, and explores how knowledge-based engineering, lean manufacturing, machine-level reconfiguration, group technology, cellular manufacturing, and mass customization contribute to enterprise sustainability. Emphasizing resource utilization, waste reduction, knowledge reuse, and adaptable manufacturing systems, Volume I provides readers with essential concepts and tools for designing resilient, competitive, and sustainable manufacturing enterprises.