The trends of globalization and digitization are having an increasing impact on customer requirements. The requirements of customers in terms of quality, delivery time and customer-specific production are constantly increasing, while at the same time costs should be reduced. In order to stay competitive, all potential for cost reduction and production increase must be exploited, including those of machines and plants. Most companies focus their investment decisions for machines and plants on the requirements that the respective machine or plant has to meet and on their purchase price. In many cases the purchase price reflects only a small fraction of the life cycle costs. In order to exploit the full potential of machines and plants, it is necessary to take all life cycle costs into account, especially operating costs. The unique characteristic of operating costs is that they can hardly be influenced after the purchase of the machine or plant. For this reason, all costs occurring during the life cycle of a machine or plant must be determined prior to its purchase in order to be able to select the best possible machine or plant for the company. To determine the optimum, the purchase price must be weighed against the operating costs. The machine or plant with the lowest purchase price can be more expensive than those with a higher purchase price if the overall costs of the life cycle are considered. On the other hand, the cost advantages cannot be used during the operating phase of an expensive machine or plant if their time of usage in the company is too short. An individual life cycle cost model, based on existing standards and concepts, was developed for AT&S AG for a systematic and holistic determination of life cycle costs. This model facilitates the investment decisions, provides a transparent presentation of life cycle costs, and compares forecast costs with actual costs. Based on the AT&S AG life cycle cost model, an Excel-based tool was developed to collect, calculate and analyse life cycle costs. Finally, the Excel tool was tested on a case study.