The paper aims to develop an intelligent modeling system using Microsoft Excel spreadsheet interface through mathematical language, mathematical reasoning and algorithms flow chart technique for manufacturing system optimization without human involvement. The paper begins to search for a mathematical theorem which is arithmetic series to represent a dynamic manufacturing system in a production floor using production time variable through numerical analysis and is validated using software simulation. The mathematical theorem is modeled with Industrial Engineering (IE) variables into spreadsheet to perform intelligent decision making. The model sets inventory target variable to be achieved with automated computation through the data input from users. Manual analysis from human can be transposed to mathematical language in order automate the system intelligently. The building of intelligent modeling system into spreadsheet using mathematical language sets a new platform for researchers to promote the next generation of modeling technique in the manufacturing field.