Composition

When two lots are blended, the resulting composition is a weighted average result of the two lots.

Composition must always be carried at a fixed number of decimal places that you define at setup. Composition must always add up to 100 percent.

If composition is available for the After To lot from the operation, use this composition for the resultant lot. If composition is not available from the operation and the To lot is empty, the system copies the composition from the From lot to the resultant lot. If composition is not available from the operation and the To lot is not empty, the system applies the blending rules.

When deriving the composition of an output lot, the system derives the composition for the resulting lot using a weighted average of the input composition. This method is illustrated in the following table:

Lot	Volume	Block	Harvest Period	Composition Material Type	Composition Percent	Equivalent Volume
Input - 101 From Before	10000	Block 100 Block 101 Block 200 Block 202 Block 100	2002 2002 2002 2002 2002	Normal Normal Normal Normal Culture	9.5 20 45 25 0.5	950 2000 4500 2500 50
Input - 102 To Before	5000	Block 101 Block 205 Block 206	2002 2002 2002	Normal Normal Normal	60 20 20	3000 1000 1000
Output - 200 To After	15000	Block 100 Block 101 Block 200 Block 202 Block 205 Block 100 Block 206	2002 2002 2002 2002 2002 2002 2002	Normal Normal Normal Normal Normal Culture Normal	6.6667 33.3333 30 16.6667 6.6667 0.0033 6.6666	950 5000 4500 2500 1000 50 1000

Lot 101 has five composition records with the percentages displayed. Each percentage is translated into an equivalent volume for the block in question. Lot 102 has a similar composition structure to lot 101. When the two lots are blended, the resulting composition is a weighted average result of the two lots. It is calculated as:

1. Equivalent Volume for each input block per Composition Material Type combination = Composition Percentage x Total Lot Volume.

2. Total Consolidated Equivalent Volume for the resulting lot = Sum of the Equivalent Volume for each block per Composition Material Type combination from all the input lots.

3. Composition Percentage for the output lot = Total Consolidated Block Volume / Total Output Lot Volume.

When composition data is generated for a blended lot, the resulting percentages, as calculated, will not necessarily total 100 percent because of rounding errors. A legal requirement stipulates that the composition data for any blend lot must sum to exactly 100.0000 percent. To balance the composition records to 100.0000 percent, you can use either of the following methods to handle rounding. Composition must always be displayed to the same number of decimal places as it is tracked.

• Apply incrementally starting with the largest value.

  A rounding factor, based upon the number of decimal places determined at implementation or some other value, is added to or subtracted from all blocks, starting with the largest and working down to the smallest until the rounding difference is eliminated.

• Apply single variance to largest value.

  The total variance is added to or removed from the largest block.