In this paper, we propose a dynamic model of an escalator which can be used to build a design database. The model permits to estimate the forces applied to the structure by calculating three primary types of forces; the torque required to operate the escalator, the reaction forces at part interconnection points, and contact forces between parts. These forces can then be used to calculate dynamic stresses in the structure which is required to estimate the durability of the structure. Result of the computer model are compared with testing results. This simulation model is used to construct a design database. So when we design a new escalator, this design database can be used to make a new simulation model which makes it possible for us to do a Knowledge-Based-Design.