When comparing returnable containers with single-use packaging, choose the same transport task and period. Use trips the container actually completed, not an assumed service life.
Build the data set
Record container acquisition, washing and repair costs, empty-return distance, and units lost or damaged. Keep product quantity as the comparison unit too.
Cost per shipment
Divide all returnable costs for the period by completed transport work. If the return vehicle carries other freight too, document how the cost is allocated.
Find the break-even trip count
Compare the returnable cost per shipment with the equivalent cost of single-use packaging. Show in a table under which trip-count scenario the returnable becomes cheaper.
Replace assumptions with measurements
Mark the result as a scenario when loss and return data are estimates. At period end, enter actual trips, washing and losses and update the calculation.
This financial threshold does not prove environmental superiority; that requires the same functional unit and product data.
