(2) Broken Stocks Management

Follows on from (1) The Broken Stocks Saga.

The first learning for me related to the broken stocks. The importance of these in achieving target qualities for each stockpile construction can not be understated. If you provide the grade controllers with a set of broken stocks that are close to quality specs, you make it relatively easy for them to hit their target. On the other hand, provide them with a set which has one or more qualities a long way off spec and you make it extremely difficult. Similarly, provide a large quantity of broken stocks and you provide more choice, provide a small quantity and even though they might be at average spec, the lack of choice (and therefore scheduling flexibility) may make it difficult to achieve target.

So whereas the short term planning group were planning the shovel excavation for the next month, I believe a much better solution would be for them to manage the broken stocks instead. The precursor to planning is to determine the quantity and quality target bands that will provide sufficient capability to meet necessary targets. The planning process then involves determining what the starting broken stocks (quantity and quality) are and then assessing which blocks need to be added to this, to either maintain it within target bands, or restore it to within target bands.

In this way, scheduling is effectively an inventory management process, which is both a key part of mine scheduling and also one that is underutilised. Inventory management will be discussed in further detail in a later blog to come.