Last week I wrote about stock control of rarely used spare parts and the consequence of getting parameters wrong, and mentioned the example of a blast furnace which needed to be cooled and rebuilt. Paul Rubin has commented that sometimes it is just bad luck for the organisation concerned. I agree. The stock control expressions for such a case are queue models, and there is always a finite chance that the demand for spare parts exceeds the number being stocked.
This evening we had a phone call about a furnace in Devon which needs to cool and be rebuilt, You can search in vain for the steel industry of this county. Iron and steel are not produced here. Other minerals have been mined and traded in Devon over many years, notably tin for centuries, silver in places, gold in minute quantities, and copper in the nineteenth century.
The furnace concerned is a glass furnace. Tina was planning to have a one-day course in glass-blowing, and the call was to postpone the course. The excellent glass artist Siddy Langley lives about ten miles from here, and last weekend she discovered that the glass pot in her furnace had cracked. There are pictures of the spectacular consequences in her blog. This is one of Paul's cases of bad luck. As Siddy says in the blog, the only thing to do is to let the furnace cool, chip out the glass which has gone solid and rebuild the furnace. There is no way that a broken pot can be replaced while the furnace is at 1200degrees C. We are sorry for Siddy, who makes beautiful glass items. No inventory control policies are appropriate for an item like this.