Propylene has its production via metathesis from ethylene and butenes reviewed. This alternative path to the traditional steam cracking or fluid catalyst cracking (FCC) units is one on-purpose method that is increasingly growing in importance in propylene production. The Report provides a process description, flow diagrams and the economics of a process similar to the Lummus OCT process. Both the capital investment and the operating costs are presented for two different locations US Gulf and Germany.