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The performances in virtual logistic (part two)
In virtual stockholding the focus it is moved on the cases where the supply
is available but it does not exist physically in the point in which the manifest necessity.
The objective of cost reduction of stoccaggio resides in the reduction or the elimination
of the supplyes in some nodes of the logistic net.
They exist you vary cases:
- The supply exists elsewhere, that is near other warehouses of the same enterprise
or the own suppliers; we can speak about virtual stockholding in the measure in which
it is succeeded in monitorare the state and the position of the materials in the
logistic net through systems informed to you ( Stuart ET al. 1995 )
in order to realize one be of " global resource visibility "
( Landers ET al. 2000 ) and to effectively manage the transfer of
the product to the customer.
To that point the problem mainly moves in choosing the breakup of the supplyes and
the control of the logistics, as an example through deliveries directed to the
customer ( Ratliff and Nulty, 1996 ).
Analogous draft the case of when the supply it still does not exist, that is
towards the center or not still be order/processed from the suppliers.
Also remaining in optical make-to-stock therefore the focus
one moves on ritagliare intervals of time for being able to eliminate of the
physical lying, as an example counting on " delivery spare times "
that is on the intervals of time that separate the order of the customer
from the cargo of the good on means of transport ( Schiraldi and Van de
Velde, 2002 ).
In both cases the performances come measured in the optical of the speed of
the system in answering to delivery the Time demanded from the customer, and
usually the performances are lower also without the necessitä to reach the
extreme case of demand for immediate availability.
- This case, abandoning the system hypothesis make-to-stock, is transformed to
the excess in the systems pull that but, as we have pointed out previously, they are
not properly identifiable like techniques of virtual stockholding.
A demonstration of the criticitā of the temporal aspect of this system has been
verified from Amazon.com , than until 1998 stoccava 2,5 million
books within a serveur in an angle of an office ( Bradt, 1998 ),
counting on the rapidity of answer of its supplier and the logistic couriers;
disservizi the offers from Amazon.com in the christmas periods of those years
(delays of delivery beyond the month) have pushed the enterprise
" to realize " the virtual warehouse, realizing a warehouse where
books come stoccati 1 fast-movers and relegating to the virtual warehouse the
slow-movers. The emergency supply is maintained in order to guarantee a sure
level of service.
Any technique that cleverly guaranteed the same level of service without the use delta
supply, with the same result, would be one virtual supply.
In the fattispecie, the techniques like the centralization of the supply in
order to take advantage of " to square root law ' that it concurs,
on the wake of how much make the banks, to maintain to supply little money (until
to 12 times less) than how much it would be necessary being based on considerations
of statistical character, are effectively virtual supplyes ( Clarke, 1998 ).
Other techniques for the lessening of the emergency supplyes are based instead on stipulate
of supply contracts that preview the possibility launch extraordinary orders
with spot deliveries ( Hawk, Nenni, Schiraldi, 2003 ).
II comparison with the performances of the real system is enough critical here:
made the opportune considerations statistics in every specific case, the system
if very tarato offers the same performances of the real system, also remaining
small probabilities of complete failure of the virtual supply, in case of (rare)
unforeseeable behaviors of the system.
The example of Unitec High Tech Industriprodukte Vertriebs GmbH ,
with center to Augsburg (Germany) extension a case of succeeding in the
centralization said supplyes of spare parts. II fact that then the system
of warehousing comes offered from the Unitec to its customers like outsourcing an
aspect of all the secondary one.
extracted from: Schiraldi, M.M, "virtuality and virtual logistic",
final relation Plan by Youngers Investigators / co-financing MURST, University
of the Studies of Rome Tor Vergata, Rome, 2001."
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