Abstract: “Computers are machines for the approximate execution of mathematical operations. By using appropriate software, computers can be used to help solve practical problems. The process of producing software is a quite complicated one and surprisingly is usually not discussed in terms of figuring out the Mathematical model that finally is going to be evaluated by the computer. In this paper we identify the software process stage, in which the Mathematical model is produced. We also discuss the Mathematical concept of quantity, how to measure quantities and Mathematical model”

Keywords: model, conceptual model, Mathematical model, quantity, amount, software process, model engineering Introduction