Jahresbericht 2006 - Biba - Universität Bremen

Synchronisation der Knoten
in Produktions- und Logistiknetzwerken
durch mobile Transponder-Erkennung
So ergibt sich eine
Transparenz entlang
der ganzen Lieferkette
Many companies today are starting to
reflect on their core-competences for the
purpose of enhancing their market position
and start cooperations with suppliers
and distributors. Thus serious connections
between independent companies develop
and production and logistics networks
emerge.
From a system theory point of view,
these companies can be seen as beeing
connected, i.e. coupled nodes in a network
and the fluctuations of their stocks or
production rate as oscillations.
On this abstract level, a real network
can be expressed as a system of
coupled oscillators. To clarify this, a simple
mechanical model can be used: the
oscillating nodes are interconnected
pendulums. In terms of this model, a “justin-time”
delivery strategy would be a rigid
link, which would force the movement of
the one pendulum upon the other. But in
general, this connection between the nodes
is more or less elastic. Consequently,
even complex network topologies can
be modelled by a system of coupled
oscillators.
The already existing theory of synchronisation
can now be applied to this
model. In this context, synchronisation
means that different system variables
(e.g. stocks or their behaviour) are similar
in their chronological sequence.
So the oscillations of the single pendulums
can be coordinated. In production
and logistics networks this would lead to
a more balanced and thereby more efficient
production, which can be noticed
in logistic performance indicators, like
inventory levels or throughput time.
An example of the positive impact
of synchronous dynamics is the so
called bullwhip-effect. This term relates
to the observation that in supply chains
consisting of more than two nodes small
variations in customer demand often
lead to strong oscillations in stocks along
the supply chain and in manufacturers’
production rates. Research revealed four
major causes for this effect: demand
forecast updating, order batching, price
fluctuation and rationing and shortage
gaming.
One possibility to synchronise such a
supply chain is to add a supplementary
link between all members of the supply
chain and a newly introduced member.
This synchronising element itself is not a
part of the supply chain and thus has no
amplifying influence on the oscillations.
Instead, it can help reduce the bullwhipeffect,
e.g. by information transparency.
One applicable solution would be an
electronic information exchange system,
e.g. a common internet platform. This
possibility can be enhanced by utilising
standardised interfaces to enable the
information exchange between different
software tools in various companies. This
would allow information transparency
along the entire supply chain and would
be a first step towards the synchronisation
of company processes.
Jan Topi Tervo
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