Purchase requisition workflow scenario - AX2012

Hi,

I need some ideas on How to setup a Purchase requisition workflow ( without using organization hierarchy) where the scenario is:

a. If total amount is below 5K, only R1 must approve.

b. If total amount is between 5K and 15K, in addition R2 must approve depending on category of item selected.

c. If total amount is between 5K and 15K, R3 must approve depending on category of item selected.

d. If total amount is between 15K and 50K, R4 must approve

e. If total amount is between 50K and 100K , R5 must approve

f. If total amount is above 100K, Corporate management ( composed with at 3 people( R6,R7,R8)) must approve.

How to use procurement categories in that case? How to make sure that the system will direct the approval to another person other than the person who creates the requisition?

Thanks

Thanks

No Idea???