Browsing by Subject "Materials handling equipment"

Now showing 1 - 5 of 5

Open Access
Beam search based algorithm for scheduling machines and AGVs in an FMS
(Institute for Industrial Engineers, 1993) Karabük, S.; Sabuncuoğlu, İhsan
This paper presents a beam search based scheduling algorithm for a random FMS. The proposed algorithm considers finite buffer capacity, routing and sequence flexibilities and generates machine and AGV schedules in varying time windows. The performance of the algorithm is measured using makespan, flow time, and tardiness criteria under various experimental conditions.
Open Access
A beam search-based algorithm and evaluation of scheduling approaches for fexible manufacturing systems
(Taylor & Francis, 1998) Sabuncuoglu İ.; Karabuk, S.
This paper presents a new algorithm for the flexible manufacturing system (FMS) scheduling problem. The proposed algorithm is a heuristic based on filtered beam search. It considers finite buffer capacity, routing and sequence flexibilities and generates machine and automated guided vehicle (AGV) schedules for a given scheduling period. A new deadlock resolution mechanism is also developed as an integral part of the proposed algorithm. The performance of the algorithm is compared with several machine and AGV dispatching rules using mean flow time, mean tardiness and makespan criteria. It is also used to examine the effects of scheduling factors (i.e., machine and AGV load levels, routing and sequence flexibilities, etc.) on the system performance. The results indicate thai the proposed scheduling algorithm yields considerable improvements in system performance over dispatching rules under a wide variety of experimental conditions. © 1998 "IIE".
Open Access
Evaluation of army corps artillery ammunition supply systems via simulation
(IEEE, 2002) Sabuncuoğlu, İhsan; Utku, D. H.
The purpose of this paper is to discuss the evaluation of different alternatives for the implementation of Turkish army corps artillery ammunition supply system. The objective is to see whether the alternative systems operate properly and to select the best system design. We find that the first alternative system cannot supply the units for all phases of an eight-day battle time while the second, the third, and the fourth systems can supply and yield better results. The third system is less costly than the second and the fourth systems. However, it has the drawback of too many vehicles in the convoy (i.e. congestion) which makes it susceptible to the enemy long distance and air assaults. The fourth system is the best of all from the point of the performance it yields; but, it costs more compared to the other systems.
Open Access
Generating robust and stable schedules in a single machine environment
(IIE, 2004) Gören, Selçuk; Sabuncuoğlu, İhsan
Scheduling is a decision making process that concerns with allocation of limited resources (machines, material handling equipment, operators, tools, etc.) to competing tasks (operations of jobs) over time with the goal of optimizing one or more objectives. The output of this process is time/machine/operation assignments. In the scheduling theory, the objective is generally to optimize one or more regular performance measures such as makespan, flow-time, and tardiness. Recently, two new measures have been also used in scheduling applications: "robustness" and "stability". In this paper, we develop a new surrogate measure to achieve robustness and stability. This measure is embedded in a tabu search algorithm to generate schedules in a single machine environment subject to random machine breakdowns. The results of extensive computational experiments indicate that the proposed method performs better than the average slack method used in the literature.
Open Access
Scheduling of automated guided vehicles in a decision making hierarchy
(Taylor & Francis, 1996) Aktürk, M. S.; Yılmaz, H.
Scheduling efforts made without considering the special limitations of the material handling system might lead to infeasible results. An analytical model is proposed, first, to incorporate the automated guided vehicle (AGV) system into the overall decision making hierarchy. A mathematical formulation is developed to include interaction between the AGV module and other modules in the system by considering the restrictions of the material handling system. A micro-opportunistic approach is then proposed to solve the AGV scheduling problem. Finally, the proposed method is compared with a number of dispatching rules.