Abstract: The most challenging issue when enterprises implement continuous improvement is how to select appropriate methods. The objective of this study is to develop a diagnosis model for analyzing appropriate improvement methods. The model is developed using enterprise diagnosis methodologies that consist of three components, the production system, fundamental management and staff mentality. These three perspectives stem from Toyota�s 3 M�s (muda, mura, muri). The applicability of the proposed model is validated using a real precast fabricator. The application results show that the developed model can be used to analyze the strategies required for introducing lean ideas in precast fabrication.