During the last several decades, manufacturing flexibility has received much attention in the areas of production and operations management. Due to the lack of refined flexibility concept, however, there has been the inevitable confusion in studying flexibility-related issues. This work attempts to clarify and unify the concept of manufacturing flexibility. First, the flexibility concept is examined from several perspectives: economics, decision theory, and manufacturing. As for manufacturing flexibility, various types of manufacturing flexibility are categorized into four types: system-determined flexibility, environment-associated flexibility, decision level associated flexibility, and learning-related flexibility. This categorization enables to synthesize various types of manufacturing flexibility into a unified framework. The proposed framework clarifies the concept of flexibility, synthesizes various types of manufacturing flexibility, emphasizes the dynamic perspective on manufacturing flexibility, and associates the notion of flexibility with various organizational levels. The proposed framework will be expected to help identify further research directions on flexibility-related issues. In addition, various strategic implications of manufacturing flexibility are discussed, especially emphasizing dynamic flexibility. Furthermore, as a way to deal with environmental uncertainties, four types of manufacturing flexibility-based "uncertainty" strategy are addressed: reactive internal, reactive external, proactive internal and proactive external. And the Japanese production system are re-evaluated from the specific perspective of manufacturing flexibility. The Japanese firms`` competitive weapons in the international markets are not necessarily their excellence in designing taut production systems such as the Just-In-Time (JIT) production control system, but their superior dynamic flexibility internalized in their organizational culture. Based on the literatur...