This document explains the concept and importance of device modeling, an essential technology in modern product development. In order to meet the ever-shortening development cycles in the electronics and automotive industries, the limitations of traditional prototyping and measurement methods have been highlighted, making the introduction of computer-based circuit analysis simulations essential. The accuracy of simulations is determined by device models (SPICE models) that represent the electrical behavior of electronic components on a computer. The process of creating these models is called device modeling. The range of models provided ranges from semiconductor components such as diodes and MOSFETs to passive components that take frequency characteristics into account, and even models of battery discharge characteristics. B Technology, the provider of this document, distinguishes itself by providing highly accurate models quickly and with detailed modeling reports to ensure designers can use them with confidence. This technology aims to shorten product development time and reduce costs, while providing environmentally friendly design methods.