This Study will introduce the concept of ATP(Available To Promise) and CTP(Capable to Promise) through the existing study , the process analysis of CTP(Capable to Promise), the modeling of algorithm and the embodiment of system. This research considers the environment of using Job-Shop method. The CTP algorithm models espicially through using LPST(Latest Possible Start Time) and EPST(Earlist Possible Start Time) method. It is important part of executing CTP(Capable to Promise), The CTP(Capable to Promise) modeling and implementing system develops to system which is capable to implement in the various business environment through addational and continuous research.