Agent-Negotiation of Lot-Sizing Contracts by Simulated Annealing with Part-Way Resets.

The distributed multi-level uncapacitated lot-sizing problem is a group decision problem which has to be solved by a set of self-interested and autonomous agents. The agents represent independent companies which have to agree on a joint production plan in a supply chain context. In order to solve the problem we extend a negotiation-based simulated annealing approach introduced by Homberger by a part-way reset procedure. The part-way reset procedure allows a negotiation based search which reaches a deadlock to continue with a different contract proposal and thereby offers a possibility of overcoming disagreements between agents more easily. A benchmark study shows that the approach is competitive on set of 80 medium sized instances from the literature in terms of solution quality, in particular 47 new best-known solutions were computed.