The company was focusing on production which was partial mission rather than acquiring the information of customer in intensive process industry. The company accepted loss which is from over-production, losing of opportunity. After changing to web environment, supply chain is more complicated and need of customer is more various. As a result the company hard works on controlling production rates, production quantities in production area and gathering exact information which is about available resource and available quantities. Cooperated demand planning have to get decreasing of inventory, improving of customer service in supply chain management. Specially demand planning that considers allocation of capacity is executed in Iron-Industry. Demand planning must be classified by customer, region and supply position level.

This Study will introduce the concept of CTP(Capable-to-Promise) Algorithm, CTP process, and the modeling of algorithm. This research is based on the environment of using Job-Shop method. CTP algorithm model use LPST(Latest Possible Start Time) and EPST(Earliest Possible Start Time) method especially. It is important part of executing CTP system. The CTP modeling and implementing develops to system which is able to implement in the various business environment through additional and continuous research.