Comparison between Cold and Hot Test procedures in a company manufacturer of diesel engines

Abstract The Cold Test is an innovative process in Brazil regarding the tests in diesel engines. This process was implemented in a diesel engine company with the intention of becoming the main validation test before engines are sent to customers. Based on this hypothesis, the main reason of this investigation is to test whether it is possible to replace the Hot Test with the Cold Test. This was a shocking question, since the Hot Test is a reliable and established process for over 18 years. This research used a case study method. The detailed research has identified several criteria for comparing the two processes, such as: flowcharts, effectiveness, efficiency, complexity, approval levels, on-board worksheets and company FMEA documents. The results showed that the Cold Test process is more advantageous and sustainable, however the two processes are complementary. The study proved that the fully replacement of the Hot Test by the Cold Test is not possible, mainly the Cold Test process fails in detecting leaks.