Information Technology Reference
In-Depth Information
work follows. Next, the Socrates trading agent and the strategies that were developed
to deal in particular with the supplier problem are described. Following this, we present
the results of the competition as well as those of a series of controlled experiments. The
paper closes with the conclusions and pointers to future work.
2
The SCM Game
In the TAC SCM game six agents compete against each other in a 220-day game which
lasts 55 minutes in real time [1]. Each agent is a manufacturer which assembles PCs
from CPUs, motherboards, memories, and hard disks. CPUs and motherboards are
available in two different product families, Pintel and IMD. A Pintel CPU only works
with a Pintel motherboard while an IMD CPU can be incorporated only in an IMD
motherboard. CPUs are available in two speeds, 2.0 and 5.0 GHz, memories in sizes, 1
and 2 GB, and disks in sizes 300 and 500 GB. The ten different components can be com-
bined into sixteen different PC models. The agents need to procure these components
from eight different suppliers. On the other side, the agents need to secure customer
orders each day. Once an agent has received an order it needs to assemble the required
number and model of PCs in its factory and subsequently ship the finished products. All
agents start the game with no money in their bank accounts, no components or assem-
bled PCs in their inventory, and no pending customer orders while they enjoy unlimited
credit from the bank. Each model of PC requires a different number of cycles to be
produced and an agent has a limited assembly capacity every day which is 2000 cycles.
The TAC server simulates the suppliers, customers, and the bank and provides produc-
tion, and warehousing services to the individual agents. The agent who makes the most
profit at the end is declared the winner.
During the game each agent negotiates contracts with the suppliers by first sending
RFQ requests for a specific type of component. Suppliers, which are utility maximisers,
reply with offers to these RFQs. In particular, in response to an agent's RFQ, they may
send a complete offer which matches the agent's request in terms of delivery date and
quantity, or partial offers that may not match the quantity or delivery date requested.
If the supplier cannot satisfy an order, no offer is sent. For every offer sent, the agent
needs to determine whether to accept it and place an order, or reject it. However, if both
partial and complete offers have been sent, the agent can only accept one of them.
The customers request PCs models for a specific due date indicating their reserva-
tion price by sending RFQs to all agents. The agent may reply with an offer bid, and the
customer awards the order to the lowest bid. The winning agent must deliver the PCs
ordered by the due date, otherwise it incurs a penalty. An agent is responsible for its pro-
duction and every day needs to send a schedule indicating how many PCs and of which
model will be manufactured the next day based on its assembly capacity. Obviously,
for manufacturing to take place the agent needs to have the necessary components in its
inventory. Components that arrive the same day can only be used in production the day
after. Each day the agent also needs to prepare a delivery schedule for the next day.
The TAC SCM game features two main interrelated problems:
The supplier problem.
One of the main problems in the TAC SCM game is to plan
a good strategy for ordering components from the suppliers. There are many factors
