Amortized investment is defined in the Site cost model rollup module. It is the sum of the following per part costs:

These per part cots are derived by dividing the corresponding total costs by the current scenario’s total production volume. The total costs are the result of aggregating the total from the current node’s child nodes in the current routing.

Total production volume is the product of the annual volume and number of production years, specified in the Production Scenario screen of the Cost Guide.