Bioplastics & Biomaterials Processing worked example

Resin Price Variance at 72% variance allocation share: a worked example

This worked example runs the resin price variance numbers for a tougher week than the baseline: 72% variance allocation share instead of the typical 100%. Estimate cost exposure from a PLA, PHA, PBAT, PBS, starch blend, or bio-compound price variance across a planned material volume.

The inputs for this scenario

  • Affected bio-resin weight: 18,000 kg or lb (held at the documented default)
  • Resin price variance: 0.32 $ / kg or lb (held at the documented default)
  • Variance allocation share: 72 % (the input this scenario stresses; the baseline uses 100)
  • Fixed supplier or freight variance: 1,200 $ (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Allocated variable resin variance = affected bio-resin weight × resin price variance × variance allocation share.
  • Total resin price variance works out to 5,347 $ at these inputs, and this is the headline figure for the scenario.
  • Resin price variance per weight unit works out to 0.3 $ / kg or lb at these inputs.
  • Allocated variable resin variance works out to 4,147 $ at these inputs.
  • Fixed supplier or freight variance works out to 1,200 $ at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where variance allocation share sits at 100% and the headline result is 6,960 $, this scenario comes in 23.17% below the baseline at 5,347 $.
  • Use it at month-end cost analysis, during a price-increase notification from a supplier, or when investigating why a bio-resin job came in over standard cost. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Total resin price variance: 5,347 $ (headline result)
  • Resin price variance per weight unit: 0.3 $ / kg or lb
  • Allocated variable resin variance: 4,147 $
  • Fixed supplier or freight variance: 1,200 $

Run it with your numbers

  • To rerun this with your own numbers, open the live Resin Price Variance calculator, set variance allocation share to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.