When a company makes a decision on an investment for a new product as a source for a new program, it is not easy for them to take a proper decision-making process in this highly volatile market. There could be several ways to make an investment decision on a new program. A company needs to choose the most suitable way of investment which is reflected current corporate circumstances and potential risks. We check up the process of the engineering economic decision in a automotive part manufacturing company. We define the gap between the theory and practice on engineering economic decisions. We present advices to make a decision desirably.