Rolling Up Costs for Yield by Operation Items

For yield by operation transactions, the Cost Rollup process calculates the yield loss for each operation sequence where the operation yield is less than 100 percent.

The Cost Rollup process performs these steps to calculate yield by operation transactions:

  1. Calculates and inserts costs into the temporary tables CE_ITMCSTDT_TMP and CE_ITMCSTD2_TMP by applying the operation yield at the operation sequence where they are first introduced.

    Each subsequent operation sequence uses the results of the previous operation sequence. Subsequent costs take the form (cost (from original OpSeq) / operation yield percent) - cost from original OpSeq.

    All components with an invalid or zero operation sequence are applied to the first operation sequence that you defined for the routing code specified. All by-products with an invalid or zero operation sequence are applied to the last operation sequence for the routing code. For by-products, the process uses the operation yield of this last operation sequence.

    This example demonstrates how subsequent costs are created as existing costs from earlier OpSeqs move through subsequent OpSeqs where Operation Yield<100 percent.

    1. The first operation sequence (OpSeq 10) has an operation yield of 100 percent. The cost is 10. Processing begins at the second OpSeq, because the first OpSeq processing is already complete.

    2. The second operation sequence (OpSeq 20) has an operation yield of 96 percent. Using the formula (Cost (from original OpSeq) / Operation Yield Percent) - Cost (from original OpSeq), then the additional cost for the cost originally introduced in OpSeq 10 would be 10/96% - 10 = 10.4167-10=0.4167.

    3. The third operation sequence (OpSeq 30) has an operation yield of 98 percent. The additional cost for the cost originally introduced in OpSeq 10 would be ((10/96%)/98%) – 10/96%) = (10.6293-10.4167)=0.2126.

    4. Therefore, the total cost is 10 + 0.4167 + 0.2126 = 10.6293 (which is the same as 10 * expected completions at OpSeq 30 = 10 / (.96*.98) = 10.6293.

  2. Once the system processes all the specified operation sequences, it moves the cost data into the CE_ITEMCOST_DET table.