FI-Segragation of Duties, Controls on Conflicting Transactions

Hi Gurus,

I need to put control checks on conflicting transactions which 4 users are having. Some of the transactions groups assigned to these users are unique and some are different.

Each transaction groups having multiple transaction codes in it. Majorly these transactions are Vendor master, invoicing, payment, F-02, MRBR, FBRA. Customer master, invoicing, payment.

Can you please let me know, on what basis should i see whether one user is having conflicting accesses and how should i put control on it?

I will be waiting for your response. Try to revert back asap.

Thank You