MATHEMATICAL MODELING FOR OPTIMAL PRODUCTION PLANNING A CASE STUDY OF THE STEEL CUTTING PROCESS

The manufacturing industry is important to the business sector and the lives of many people, especially the steel industry and metal processing is one of the important industries in Thailand. The case study company wants to solve the problem of planning for the gas steel cutting process that does not go as planned, which sometimes causes delays in delivery to customers. Therefore, the researcher presents the application of statistical methods by analyzing multiple linear regression to evaluate the time in the steel cutting process based on the length and thickness of the steel sheet. In addition, a mathematical model is applied for appropriate production planning. The research results found that the length and thickness of the steel sheet have a statistically significant effect on the time. After that, the equation used to evaluate the cutting time according to customer needs, together with the schedule in the mathematical model, was used. The target equation was set to be the maximum profit, and the Excel Solver tool was used to calculate the most suitable time to cut steel each day. The mathematical model obtained from the research operation in planning the steel scooping process can increase the maximum profit after delivering the work to the customer, increasing by 65.88 percent from the original production plan. This model can be applied to the company's actual production planning according to customer needs.