Prepare a master schedule given this information:

It is now the end of week 1; customer orders are 25 for week 2, 16 for week 3, 11 for week 4, 8 for week 5, and 3 for week 6. Use the MPS rule of ordering production when projected on-hand inventory would be negative without production. Suppose that a production lot size of 70 pumps is used. (Leave no cells blank - be certain to enter "0" wherever required.)

	June				July
64	1	2	3	4	5	6	7	8
Forecast	30	30	30	30	40	40	40	40
Customer orders (committed)	33	25	16	11	8	3
Projected on-hand inventory
MPS
ATP

These are the answers:

Particulars	June 1	June 2	June 3	June 4	July 5	July 6	July 7	July 8
Inventory	64	31	1	41	11	41	1	31
Forecast	30	30	30	30	40	40	40	40
Customer orders	33	25	16	11	8	3	-	-
Projected on hand inventory (See Note 1)	31	1	41	11	41	1	31	61
MPS (See Note 1)	-	-	70	-	70	-	70	70
ATP (See Note 2)	6	-	43	-	59	-	70	70

I just need how the ATP was arrived. Please do explain to me.

Thank you.