Grid applications can be modeled as a composition of rather independent tasks. There are two approaches to define such a workflow either by combining multiple applications to build a more complex functionality or by splitting up an existing application. In this paper we analyze the latter process. We present a compute intensive application for climatology simulation and the options available to split it up. Using the simulation mode of our grid broker, we were able to compare the different workflow specifications before actually executing the workflows. This case study showed, using finer grained workflows-which usually need more adjustments to the software-allows better performance in the grid.