GEOList Summary: Funding Area Allocations

For a number of years, our foundation has split its annual grantmaking allocation evenly between three separate programmatic areas. Our board is planning to review this structure to determine whether to continue as is or, perhaps, concentrate more funding in just one or two of the programmatic areas while cutting back in a third. I am wondering what the process is that other foundations use to determine allocations among grantmaking program areas.