Problem $13-7($Static$)$

Eighty units of end item $x$ are needed at the beginning of week $6,$ and another $30$ units are needed at the beginning of week $8.$

Prepare a material requirements plan for component D$.$ D can only be ordered in whole cases $(50$ units per case$).$ One case of $D$ is automatically received every other week, beginning in week $1($i$.$e$.,$ weeks $1,3,5,7).$ Also, there are $30$ units of $B$ and $20$ units of $D$ now on hand. Lead times for all items are a function of quantity: one week for up to $100$ units, two weeks for $101$ to $200$ units, three weeks for $201$ to $300$ units, and four weeks for $301$ or more units.

Note: Leave no cells blank $-$ be certain to enter $"$O$"$ wherever required.