Current storage trend includes more and more outsourcing the expensive
spare parts with slow turnover rates into supplier storages. In these
cases the supplier commits to storing the spare parts in its stock and
delivering them to the customer in a certain time.
As an example will be used the previously
item "Bearing 23456" and the goal is to find out how much its outsourcing
is allowed to cost so that it would be profitable.
The estimation of the problem can be started by examining the item
optimization made with the StockOptim software. The overall
costs coming from the storing of item "Bearing 23456" were 306.95 €/year.
Also it is necessary to take notice that with the optimized storage
strategy (reorder point = 5, order size = 4)there were no shortage
situations in the storage with the current spare part consumption. With
these results in mind it can be said that if the supplier guarantees
to store the item cheaper than the previously mentioned 306.95 €/year
and can provide same service rate for the item, it is on average
profitable to store the item at the supplier.
In practice storing the item "Bearing 23456" at the supplier would
mean a supplier managed storage close to the usage location, because
the costs coming from delayed distribution would be extremely high
compared to the storing costs.
If it would be evident that storing the item at the supplier storage
would cause more delay compared to the current storing method, that would
be caused by the transportation of the item from the supplier storage
to the usage location, it would be possible to calculate the costs
coming from the delay with StockOptim software. As an example the
storing of the previously optimized item "Bearing 23456" is moved to
a supplier storage, that causes a delay of one hour with a standard
deviation of half an hour to get the spare part to the need location
compared to the scenario where it would be stored in the own storage
of the location. What would be the extra costs coming from this delay
if the shortage cost is 10000€/hour?
The calculation is performed with StockOptim software by changing
the item delivery time to 1 hour with a standard deviation of half an hour.
This will give us the results concerning the shortage costs coming from
increased delivery delay:
Extra delay in average 1h with deviation of 0.5h
(a = average value, s.d. = standard deviation ja 95% = 95% quantile)
As previously noted the storing of this item should be kept as close to
the usage location as possible due to the high shortage costs.
The result of the example could have been easily predicted without
StockOptim software, but the case at hand is often much more complex
than this. If for example the consumption would be divided between
many usage locations which all would have different shortage costs
(some of the locations would suffer e.g. slower production or reduced
quality) and item need times, then the calculation would be extremely
challenging without StockOptim software.