In today’s highly competitive and challenging marketplace, manufacturing process improvement is more important than ever before. Conversely, it is probably also harder to achieve than at any time in the past. This is due to several factors. High levels of capital investment combined with short product life cycles mean that maximising utilisation levels of expensive equipment is essential. Increasingly complex production facilities are difficult to analyse and improve. The possibility of worsening the situation rather than improving it means that experimentation on the line itself is often a risk not worth taking. One solution to this problem is the use of computer based manufacturing system simulation. Simulation studies are beneficial because they remove the element of risk associated with experimentation. Potential process improvement strategies can be identified, evaluated, compared and chosen in a virtual environment before eventual implementation on the factory floor. This research aimed to evaluate the use of discrete event system simulation in a real world manufacturing environment. To this end, a flexible simulation model of the main transfer line of Läpple Ireland, a large metal panel production facility, was designed and constructed using Extend simulation software. In conjunction with Läpple personnel, various ‘what if’ scenarios were identified and evaluated. These scenarios were aimed at deciding the best position for providing additional automation by investing in robots. From the results of the simulation modelling of the three main proposed modifications to the line, improvements of 9%, 18% and 33% in press line throughput were predicted. The negative effect on these improvements in the case that the proposed robots failed to achieve the desired speeds were evaluated. These negative effects were found to be not as dramatic as could be expected. The results were compared to those of similar research efforts elsewhere. Finally, future steps for the research to take were identified and suggestions for future areas of application for the model were made.