OpenGl ES VShader analysis

Hi,
I am working as an intern in one of my dream company. My tutor/supervisor asked me to implement an GLSL shader analysis toolkit on mobile devices which I have little Idea about it.
The idea of the GLSL shader analysis toolkit is to run this program on different mobile devices and then to give artists a straightforward impression which operation is the most expensive: FShader, VShader, Rasterisation or Band-width. But I do not know how to measure VShader (The idea of VShader part is to measure what’s the max vertex number a mobile devices can support, given a shader).

In short, I am looking for help about an Opengl benchmark on mobile devices.

PS, I have implemented the analysis on FShader by drawing many screen quads with a given shader, minus the performance of drawing many screen quads with a void FShader. I just want a general idea of the cost and do not want to involve with compiler and hard-ware things.

The Best