Purchase Orders - Blanket with interchangeable parts

We buy Aluminum in various sheet sizes and write large purchase orders which we take delivery on over a few months. We define an aluminum sheet in a specific size as a part, with sheet as the inventory UOM and LB as the purchasing UOM.

When we order the aluminum, we commit to buy X number of LBs at a certain width which will be released to us in various lengths, which we can change at the time of release. The timing, qty and exact size of each release always changes but we take the total weight in the time period defined at the time we place the order.

How would all you Epicor gurus set up the process to record these transactions in a way that is easy and traceable. The two ways we are considering are as follows, but they both leave us feeling a little incomplete.

  1. When the PO is initially entered, we make our best guess of the distribution between sheet sizes with a comment that the PO will be released as requested before some future date and sheet sizes are subject to change at the time of release. Then, once the PO is winding down, we will increase the Qty on some sizes and decrease the Qty on others, all with the total weight of parts on the PO staying the same, +/- rounding.

  2. We set up a generic part number for Aluminum Coil, size TBD at time of release. Then, when we call in a release on the PO, we remove the qty from this line and add it to the part number that relates to the size we want for this release.

We use option 2 for painted metal coils and it works great.

Our blanket PO has a line for each color and an estimated quantity for the year. When we actually order a coil we enter a new line for that coil and reduce the amount of the initial line.