The paper presents a checklist application focusing on a liquefied gas-handling simulator - Liquefied Petroleum Gas (LPG) type. The concept of using checklists for such tasks is based on previous research and the authors' own experiences collected during operational investigations of the engineering lab-simulators at Gdynia Maritime University, Gdynia, Poland, namely the engine room simulator (ER-SIM) and the LPG type. A proposed checklist for each handling operation (procedure), which can be used in the LPG-handling simulator, is also presented. An example of the checklist is presented at the end of the paper. The hypothesis is put forward that such a list could be implemented in a similar form in real life, eg on LPG-carriers as an interactive operation manual. However, the checklist seems to be a prescription or a way of operating the complex systems. It should be noted that it is only a helpful device for operating such systems, so it can not release operators from the obligation to improve their theoretical and practical knowledge, including knowing the system structure, the operational principles of basic system components, the cause and effect table in order to correctly diagnose emergency situations, etc.