The misinterpretation of economic manufacturing lots

We have learned that high non-recurring costs lead to large batches. According to business economics theory, preproduction costs are to be calculated as nonrecurring costs in internal production. 

But careful Preproduction costs are generally determined as follows  

This produces high non-recurring costs which push up the lot sizes for internally-produced parts and thereby the capital tie-up in inventory. 

You can see that the enterprise has no loss in profit except for the hour the machine operator takes to retrofit the machine, provided he would otherwise be occupied with other value-added work or had to put in overtime. Why do we not employ the unused machine time more frequently for retrofitting Why should this time suddenly costs as much as the machine hour rate It is thus ridiculous economically to push lot sizes up through statistical non-recurring costs like the na-chine hour rate. 

You can immediately begin gradually reducing the lot sizes for all internally-produced parts that do not pass through real bottleneck machines. Your inventory of semi-finished products will also decrease accordingly. 

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