Browsing by Subject "Supply chain scheduling"

Now showing 1 - 3 of 3

Open Access
Auction based scheduling for distributed systems
(International Institute of Informatics and Systemics, 2006) Zarifoğlu, Emrah; Sabuncuoğlu, İhsan
Businesses deal with huge databases over a geographically distributed supply network. When this is combined with scheduling and planning needs, it becomes too difficult to handle. Recently, Fast Consumer Goods sector tends to consolidate their manufacturing facilities on a single supplier serving to a distributed customer network. This decentralized structure causes imperfect information sharing between customers and the supplier. We model this problem as a single machine distributed scheduling problem with job agents representing the customers and the machine agent representing the supplier. We developed Auction Based Algorithm by exploiting the opportunity to use game theoretic approach to solve the problem in the decentralized utility case. Results of our extensive computational experiments indicate that Auction Based Algorithm converges to the upper bound found for the total utility measure.
Open Access
A class of joint production and transportation planning problems under different delivery policies
(2013) Koc, U.; Toptal, A.; Sabuncuoglu, I.
This paper examines a manufacturer's integrated planning problem for the production and the delivery of a set of orders. The manufacturer in this setting can use two vehicle types for outbound shipments. The first type of vehicle is available in unlimited numbers, but expensive. The second type, which is relatively low in its price, has limited and time-varying availability. We analyze the manufacturer's planning problem under different delivery policies characterized by each of the following: whether orders can be split or not, whether they can be consolidated or not, and whether their sizes are restricted to be in integer multiples of vehicle capacities or not.
Open Access
Coordination of inbound and outbound transportation schedules with the production schedule
(Elsevier, 2017) Koç, U.; Toptal, A.; Sabuncuoglu, I.
This paper studies the coordination of production and shipment schedules for a single stage in the supply chain. The production scheduling problem at the facility is modeled as belonging to a single process. Jobs that are located at a distant origin are carried to this facility making use of a finite number of capacitated vehicles. These vehicles, which are initially stationed close to the origin, are also used for the return of the jobs upon completion of their processing. In the paper, a model is developed to find the schedules of the facility and the vehicles jointly, allowing for effective utilization of the vehicles both in the inbound and the outbound. The objective of the proposed model is to minimize the sum of transportation costs and inventory holding costs. Issues related to transportation such as travel times, vehicle capacities, and waiting limits are explicitly accounted for. Inventories of the unprocessed and processed jobs at the facility are penalized. The paper contributes to the literature on supply chain scheduling under transportation considerations by modeling a practically motivated problem, proving that it is strongly NP-Hard, and developing an analytical and a numerical investigation for its solution. In particular, properties of the solution space are explored, lower bounds are developed on the optimal costs of the general and the special cases, and a computationally-efficient heuristic is proposed for solving large-size instances. The qualities of the heuristic and the lower bounds are demonstrated over an extensive numerical analysis.