Completing the Bill of Materials
1. Selecting and Adding Materials, Trims, and Packaging
Updating Net Use
Once all materials are added to the Bill of Materials and the amounts are specified, the net use may need to be adjusted to ensure an accurate product net weight. An accurate net weight ensures that the impacts of finished assembly processes, distribution impacts, and use phase impacts can all be calculated correctly.
The default net use (or yield) for materials varies based on Product Type. For Apparel and Home Textiles, the default is 80%. For Footwear, the default is 70%. For Trims and Packaging, the default is 100%,since each unit is treated as discrete and the net yield has already been accounted for when creating the Trim or Packaging.
If the correct net use for a material is known, the default value for that material can be updated. Even if the specific net use is not known, it is still possible to estimate it by knowing the correct product net weight. If the product net weight in the product assessment is higher than the actual net weight, then the net use can be decreased. If the product net weight in the product assessment is lower than the actual net weight, then the net use can be increased. The following formula can be used to help estimate how the new net use should be updated:
Estimated Net Use = Default Net Use * Product Net Weight (Actual) / Product Net Weight (Higg PM)
This new estimated net use can then replace the default.
When conducting a product assessment for a product that has a range of sizes, the middle size (usually size medium for apparel) should be used when considering the actual product net weight. The middle size is considered the size on which the pattern grading is based.
Example (Updating Net Use)
A garment is made up of a single custom material. Since the Unit of Measure was specified for this material in the Higg MSI, the gross amount is specified as 1.8 yards of material. However, once this is entered, the Product Net Weight shows the product as weighing 0.400 kilograms. The actual garment weighs 300 grams (0.300kg). Since the cutting efficiency is not known, the estimate net use equation is used:
Estimated Net Use = 80% * 0.3kg / 0.4kg = 60%.
The Net Use field is updated to 60% for this material to make the product net weight in the Higg Product Module match the actual product net weight.