You do not need more information. I solved it. I think you mighg be confused because it says sixty three and not 63 !

Problem 21-11 Assume that Product Z is made of two units of A and three units of B. A is made of three units of C and four of D. D is made of two units of E. Lead times for purchase or fabrication of each unit to final assembly are: Z takes two weeks; A, B, C, and D take one week each; and E takes three weeks. Sixty three units Of Product Z are required in Period 10. (Assume that there is currently no inventory on hand of any of these items.) b. Develop an MRP planning schedule showing gross and net requirements and order release and order receipt dates. (Leave no cells blank - be certain to enter "0" wherever required.) 1 2 3 4 5 6 7 8 9 10 Item Z OH = 0 LT = 2 O=L4L Item A OH = 0 Period Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts TTTTTT SS=0 Q = L4L Item B OH = 0 IT=1 SS=0 O=L4L Planned order releases Item C OH = 0 LT = 1 SS=0 Q = L4L Item D OH = 0 Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases Gross requirements Scheduled receipts Projected available balance Net requirements Planned order receipts Planned order releases LT=1 SS = 0 Q = L4L Item E OH = 0 LT = 3 SS = 0 Q = L4L