The field of lean systems engineering (LSE) has recently emerged in systems engineering (SE). This concept applies the lean concept, which originally comes from the Toyota production system (TPS), to one-off applications, such as large complex development projects for aerospace and the military. Some lean principles are generally used in Japanese manufacturing companies and are not unique to Toyota Motor Co.; the concept referred to as the Japanese production system (JPS), is an important factor in making an enterprise sustainable through continuous and endless improvement activities for marketing and quality management. TPS has been extended from production systems to product system development and enterprise management for repetitive manufacturing industries, and is called enterprise TPS (E-TPS) in this paper. This paper decomposes the E-TPS concept into three components from the original TPS, JPS, and SE, and proposes the idea of a lean and sustainable enterprise. This is yet another interpretation of LSE based not on lean concepts, but TPS.