1. A method for optimizing stream processing programs adapted to be executed by a stream processing system, wherein the stream processing system includes a first and a second programmable stream processing units, wherein the second stream processing unit is connected with the first stream processing unit such that the output of the first stream processing unit is adapted to be the input of the second stream processing unit, the method comprising: receiving a first stream processing program adapted to be executed by a first stream processing unit, wherein the first stream processing program includes an output parameter; receiving a second stream processing program adapted to be executed by a second stream processing unit, wherein the second stream processing program includes an input parameter corresponding to the output parameter of the first stream processing program; and optimizing the first and second stream processing programs based upon the correspondence between the input parameter of the second stream processing program and the output parameter of the first stream processing program.