ERP & MRP Planning worked example

MRP Material Requirements with gross material requirement of 630 units: a worked example

This worked example runs the mrp material requirements numbers for a tougher week than the baseline: gross material requirement of 630 units instead of the typical 1,250 units. Calculate net material requirements from gross demand, on-hand inventory, scheduled receipts, and other usable supply.

The inputs for this scenario

  • Gross material requirement: 630 units (the input this scenario stresses; the baseline uses 1,250)
  • Available on-hand inventory: 420 units (held at the documented default)
  • Open PO or work-order receipts: 300 units (held at the documented default)
  • Approved substitute or reserved supply: 80 units (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Net material requirement = gross material requirement - available on-hand inventory - open receipts - approved substitute or reserved supply.
  • Net material requirement works out to 0 units at these inputs, and this is the headline figure for the scenario.
  • Total usable supply before requirement date works out to 800 units at these inputs.
  • Gross material requirement works out to 630 units at these inputs.
  • Supply coverage of gross requirement works out to 0 % at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where gross material requirement sits at 1,250 units and the headline result is 450 units, this scenario comes in 100% below the baseline at 0 units.
  • Use it whenever you net a part during MRP planning, before releasing a planned purchase order or work order, or when validating what an ERP run actually proposed. 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

  • Net material requirement: 0 units (headline result)
  • Total usable supply before requirement date: 800 units
  • Gross material requirement: 630 units
  • Supply coverage of gross requirement: 0 %

Run it with your numbers

  • To rerun this with your own numbers, open the live MRP Material Requirements calculator, set gross material requirement to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.