Japanese companies tend to implement 5S as an autonomic nervous system to keep manufacturing activities running smoothly, as well as to avoid Muda. However, 5S implementation could potentially cause several impacts if it does not run consistently. Therefore, this study analyzes the impact of inconsistencies in 5S implementation. This research will be conducted with a qualitative method, using observation as primary data, and interviews as supporting data. Additionally, the descriptive analytics method would be implemented to adjust collected data with theories from a literature review. The result from the study is the inconsistency of 5S at PT Indonesia Toray Synthetics causing Muda. The Conclusion is that there are several forms of Muda due to the inconsistencies of 5S implementation. The main factors causing the inconsistencies in the implementation of 5S at PT ITS are cultural differences between management systems and the majority of local workers. The solution that can be done in this case is to hold training and simulations that are scheduled by the management and carried out routinely by all workers.