Some work has already been undertaken to replace ADI with calls to the Abstract Data Functions (ADF) library. See the directory /lsoft1/asterix/work/rb/adf for examples.
Stated simply, all calls to ADI have been replaced with identical calls to ADF. This allows for the minimum of change to the structure of applications and subroutines. The task is then to devise black-box replacements to perform the identical function as the old ADI call.
Also, all calls to BDI have been replaced with identical calls to BDF for the same reasons. The majority of this work is a simple find and replace of the string "ADI" with "ADF" and "BDI" with "BDF".
To date around 50 packages that call these routines (grf, fit, hsi, &c) have not. Currently working versions of STATISTIX and BINLIST exist, along with a partial conversion of REBIN.