Hi Praveen,
Don't make the authorization matrix at transaction level.
Make them in object level. objects holds the field level authorizatoins.
If you have any further doubts, to identify these objects for transaction wise, you can use the table "USOBT", where you can see the relationsship of the authorizatoin objects vs. fields.
In EHS most of the trasactions holds multiple activites like work benches. It is very difficult to control the authorizations in transaction level.
There are couple of BADI's also available to control the user specific authorizations.
for ex - EHSH_POH_CHECK_AUTH
Regards
kamal