[sneeeeeep]

>Some operations, especially those that buy in bulk (or have other variable cost considerations) to go great pains to understand their actual costs. In these cases, and average bulk cost (total cost / total items) will not provide the detail (and timelines) required for understanding their [actual] costs.
>
>The costing rules are very stringent - and been around since Pharo rule Egypt!
>
>Was this a bit over the top?:-)

That's exactly where we didn't want to go, back then :). We're talking permanent inventory, not materials, and those two were separate apps back home. Permanent inventory (aka "basic means", or "foundation resources" in Serbian) was always booked by total value. As for materials, or material accounting, they came in all colors - instant average, monthly average, LIFO, FIFO, and the ultimate sophistication: each buy of an item as a separate item. Each one had its troubles. I've once seen ("seen" is an understatement - "stared at it for half an hour" would be more correct) an example where monthly average, the one calculated at the end of the month and applied retroactively to all pulls for that month, ran the average price into negative numbers, because of the wild fluctuations in the price.

And it sounds so simple in the beginning...