In this paper, we present a real life assembly line balancing problem for a motorcycle manufacturing company. Results from the initial situation in the company are compared to those provided by a heuristic method and by a novel neighbourhood search method. An ARENA simulation model is developed to test the different proposals. The model was validated by comparing the simulation results from the initial company scenario with the real operation results. Consequently, the extension to the developed proposals allows us to select an adequate assembly line for the company, resulting in a greater productivity level and a more balanced line with respect to the operation times in the stations and the activity of the workers. The company has subsequently implemented our proposed schedule, obtaining remarkable improvements in its productivity.