Reordering policy in manufacturing

Dear Experts,
I'd like to ask about maximum qty, one of the reordering policy in navision manufacturing.
My problem is how the navision calculate it.
Repelenishment system : Item A = production order ; item B = purchase item,
location set = grey
Inventory : item A = 100 unit ; item B= 200 unit; Prod. BOM : item A = 1 unit need 1 unit item B.

Case A.
SO qty to customer= 100 unit; location= grey; in the tab planning for item A and item B: qty max. inventory = 300 unit;
qty reorder point = 100 unit; Reordering policy = maximum qty
by using order promising and
Planning worksheet generate : qty item B = 600 units, item B = 100 units ; item A = 300 units. location = none

Case B.
SO qty to customer= 50 unit ; in the tab planning for item A and item B: qty max. inventory = 300 unit;
qty reorder point = 100 unit; Reordering policy = maximum qty
by using order promising and
Planning worksheet generates : qty item B = 600 units, item B = 100 units ; item A = 300 units. location = none

Case C.
SO qty to customer= 200 unit ; in the tab planning for item A and item B: qty max. inventory = 300 unit;
qty reorder point = 200 unit; Reordering policy = maximum qty
by using order promising and
Planning worksheet generate : qty item B = 600 units, item B = 200 units ; item A = 300 units. location = none

Case D.
SO qty to customer=300 unit ; in the tab planning for item A and item B: qty of max. inventory = 300 unit;
qty reorder point = 300 unit; Reordering policy = maximum qty
by using order promising and
Planning worksheet generate : qty item B = 600 units, item B = 300 units ; item A = 300 units. location = none


Case E
SO qty to customer= 100 unit ; in the tab planning for item A and item B: qty max. inventory = 300 unit;
qty reorder point = 50 unit; Reordering policy = maximum qty
by using order promising and
Planning worksheet generate : qty item B = 600 units, item B = 50 units ; item A = 300 units. location = none


in all of the cases there are three results but 2 results are stable in qty but the other changes according to qty
changeover in reorder point.my questions are as follows:
a. why the item B qty > qty maximum inventory set in its planning tab
b. why the location is empty
c. why the system separated the reorder point of item B from item B qty generated in planning worksheet
:-k :-k
Please let me have the answer from all the experts here.

rgds,
Johnson "Operation Babylon" Alonso