# Poka Yoke in Smart Production Systems with Pick-to-Light Implementation to Increase Efficiency
## 1 Introduction
### Poka Yoke and Pick to Light  
The term Poka Yoke, in English Mistake Proofing or Error Proofing, is composed of two Japanese words \"Poka\"--unintentional mistake and \"Yokeru\"--prevent. The Poka Yoke concept has been used in various forms since the beginning of mass production. Its author was the Japanese innovator [PERSON], the first to present this method at Yamada Electronic Company in 1961. However, like most Japanese methods, this one became better known worldwide only after its use in the United States of America in the 1980s and 1990s. The initiator for the Poka Yoke implementation in the American automobile industry was the expert [PERSON], who successfully adapted it to the requirements of the American sector [4]. The Poka Yoke principles are shown in Figure 1.  
The design of an \"error prevention tool\" is a procedure in which mechanisms are introduced into the process environment or the process itself to prevent a given erroneous operation from occurring at all [3]. The method is preventive and based on the principle of zero error occurrence in the process. Control elements focus on the initial stage of the process and the inputs themselves before the active activities that add additional value to the inputs occur. An error in the production process is defined as any deviation from the predetermined technological, possibly working, drawing requirements, or even the smallest deviation from the correct product functioning. Almost all mistakes can be prevented in some way [5]. The cause of errors in the process is, in most cases, the employee themself. Errors can generally be divided into two categories:  
1. Process errors arise from incorrect production environment design, workplace, procedures, etc. 2. Errors caused by employees--the human factor is at work here. The main mission of the Poka Yoke method is to identify and prevent errors. If they do occur, the defective product must not reach the customer. Pick to Light is a method within the logistics and warehouse system that increases the effectiveness and process efficiency of picking goods from shelving plans. The basis of this method is light indicators directly placed on shelves or racks, which show the operator which items to select and in what quantity. The operator turns on the light indicator for a specific item and takes it, confirming the task's completion. In this way, the possibility of confusion or the incorrect selection of goods is minimized and the speed and accuracy of the process is increased [4,5]. The connection of Poka Yoke and Pick to Light could be realized in such a way that the light indicators in the Pick-to-Light system would be designed to indicate specific items to be selected and possible errors or deficiencies in the performed tasks. For example, if the operator picked the wrong item or in the incorrect quantity, the system would use indicator lights to indicate this error [6]. This way, Poka Yoke would be used to prevent errors in the Pick-to-Light process and ensure that the operator picks the correct items in the right quantity. Both systems, Poka Yoke and Pick to Light, contribute to improving the quality, accuracy and efficiency of production processes. Reducing errors, increasing productivity and enhancing safety are benefits that can directly impact the success and competitiveness of smart manufacturing systems [3,7]. The implementation of Poka Yoke and Pick to Light in smart manufacturing systems can face some challenges:  
Poka Yoke [6]:  
* Implementation complexity: Designing and implementing Poka Yoke requires thorough production process analysis, potential error identification and the creation of appropriate control mechanisms. It can be time and resource-intensive. * Changing work practices: Introducing Poka Yoke may require changing work practices and employee habits. Some employees may resist change, so providing adequate training and support for their adaptation is important.