ABS Technical Bulletin #3

Processing Unit Weight Materials

(tubs, bins, sows, etc.)

The Alloy Blending System computes the optimal solution for a charge design, then reviews the solution to determine if any unit weight materials were selected. If none were selected, the process is complete and a least cost charge design report is displayed.

If unit weight materials are selected, ABS has three different options available for processing them. These options all assume the material name is the same for the various pieces and that more than one piece is available for use.

Key information such as Material Name, Optimal Weight, Class Code Index*, and Location will be written to a temporary work file and then sorted. If Directory Editor Special Option #58 (Optimize Materials by Row/Column) is set to NO, the file is sorted by Material Name, Location, and Unit Weight (in descending order). If Special Option #58 is set to YES, the file is sorted by Class Code Index and Material Name.

At this point, the actual processing of the unit weight materials begins.

MASTER DIRECTORY SPECIAL OPTION #58 = NO (DEFAULT)

When Special Option #58 is set to NO, each unit weight material record is read and processed as follows.

If the Optimal Weight is less than the Optimal Unit Percentage**, the minimum and maximum value for the material is set to zero.

If the Optimal Weight is greater than the Optimal Unit Percentage, the minimum and maximum value for the material is set to the material’s unit weight or to an amount that is a multiple of the unit weight.

The next unit weight record is then read. If the next material name is different from that of the last record, the program then sets the maximum value to zero for all unit weight materials with the last record’s name (that were not selected as candidates) before processing the next material. This procedure is repeated until the material name changes or until all unit weight materials with the same name have been processed.

For example, Figure 1 displays key information about five different unit weights:

Figure 1

The materials are always read and processed by name and lot number order. If all materials in Figure 1 had the same chemistry and same cost, and if the optimum solution was 911 lbs., the 911 would be for lot 100. Since 911 is 60% of the unit weight, this material would be rejected by ABS since the optimal unit percentage is set to 85%.

It is at this point that the processing of unit weight materials varies by company. Most clients have multiple lots with the same name and same chemistry. Therefore, if one tub/bin doesn’t fit (because of unit weight constraints), we can substitute another one. In Figure 1 we could use lots 300 and 500 (total of 900 lbs.) or lot 400 (900 lbs.) to satisfy the 911 lb. optimal weight desired.

If custom option #17 in the CUSTOM.KSI file is activated (set to YES), the program will sort all of the lots in descending order (see Figure 2) and try to get the 911 optimal weight. The program would, therefore, select lot 400 to satisfy the 911 lbs. required and set the min and max weight to zero for all other lots.

Figure 2

Some clients use the material name to indicate the material supplier or vendor. If this method is used, then each material may have a very different chemistry and cost, and we shouldn’t attempt to reassign the optimal weight to the other group in descending or ascending order. We need to process each material as a unique item. This is done automatically by ABS — no option needs to be set to force ABS to operate in this mode.

MASTER DIRECTORY SPECIAL OPTION #58 = YES

When Special Option #58 is set to YES, each unit weight material record is read and processed as follows.

The sorted work file contains one record for each unit weight material selected. If the Class Code Index is greater than 3, the lot number is assigned as "(All Lots)". For example:

Since this file was sorted by Class Code Index, if any Index 1, 2, or 3 materials were selected, they will appear first and be processed first. If the unit weight record has a Class Code Index of 1, 2, or 3 then it is processed exactly as if Special Option #58 were set to NO. See the earlier explanation.

NOTE: All sub-classes of Class Codes 1, 2 and 3 will also be assigned Index 1.

If the unit weight record has a Class Code Index greater than 3, the optimal weight will be the "total" optimal weight for all unit weight materials with the same name. The program then begins to assign the total optimal weight to these materials by Row and Column. The material’s Row and Column identifier is derived from the Location Field. When Special Option #58 is set to YES, the Location Field is redefined as:

When the program processes Special Option #58 materials (those with a Class Code Index greater than 3), the following procedure is performed. Following is the true optimal solution based upon cost for item MG2:

After the total weight is determined for the material, the program starts with the first material in the row and attempts to set the minimum and maximum weight to the unit weight. If successful, the weight assigned is subtracted from the total optimal weight, and the program proceeds to the next material in the row. For example: