The train represents a complex system, where every sub-system has an important role. If a subsystem doesn’t work how it should, the correctness of whole the train can be uncertain. To ensure that system works properly, we should test each sub-system individually and integrate them together in the whole system. Each of these subsystems consists of the different modules with different functionalities what should be tested. Testing of different functionalities often requires a different approach. For some functionalities, it is necessary domain knowledge from the human expert, such as classification of signals in different use cases in Propulsion and Controls (PPC) in Bombardier Transportation. Due to this reason, we need to simulate of using experts knowledge in the certain domain. We are investigating the use of machine learning techniques for solving this cases and creating system what will automatically classify different signals using the previous human knowledge. This case study is conducted in Bombardier Transportation (BT), Västerås in departments Train Control Management System (TCMS) and Propulsion and Controls (PPC), where data is collected, analyzed and evaluated. We proposed a method for solving the oracle problem based on machine learning approach for different for certain use case. Also, we explained different steps what can be used for solving the test oracle problem where signals are part of verdict process