The aim of the article is to present HERCA, which is a tool for research of the reasons for human error. HERCA is a complement to the methods and tools such as 5W1H, Ishikawa's diagram or 5 Why. Man and his actions are very important in all work processes but also are the weakest link. HERCA enables precise indication of error reasons and allows to make a deeper analysis and becomes one of the elements of continuous improvement in communication and retention of the key elements of tasks by employees and supervisors. Eliminating human errors avoids serious failures, downtime so that the enterprise’s efficiency is better. The accidents or near misses have a negative influence on the image of the company and involvement of employees in the work process. Consciousness of the safety of performing work improves the comfort of employees.