It is not possible to eliminate all the mistakes people make. People are not mistake proofed by their nature. But organization can avoid these mistakes from reaching the customer, which is known as a defect in this case. Mistakes can be stopped as soon as they happen at least. Poka Yoke is very simple concept in nature. The basic concept of this is avoiding the problems by correcting the process. Poka-yoke is a quality assurance technique developed by Japanese manufacturing engineer Shigeo Shingo. The aim of poka-yoke is to eliminate defects in a product by preventing or correcting mistakes as early as possible. Poka-yoke has been used most frequently in manufacturing environments. Japanese industrial engineer Shigeo Shingo developed Poka Yoke (to avoid (yokeru)  inadvertent errors (poka) ) along with "source inspection" as a means for achieving Zero Quality Control (ZQC). Shingo introduced these ideas in his book Zero Quality Control: Source Inspection and the Poka-yoke System. Poka - Yoke systems reduce the cost of failure dramatically. No defective part will be passed to the next process. So at the end of the process you can trust that you have a good quality parts on your hand. Poka yoke is one of the critical steps in the lean journey. This project implements Poka-Yoke system for Gear assembly. Project system can recognize that the worker has to pick gear as per defined sequence. Even it can recognize the position of the gear when all process is done successfully then signal send to Press to inject gear assembly in engine.