Hybrid heuristic search for the scheduling of flexible manufacturing systems using Petri nets

Abstract

The combination of Petri nets (PNs) as an analysis tool for discrete-event dynamic systems and artificial intelligence heuristic search has been shown to be a promising way to solve flexible manufacturing systems (FMS) scheduling problems. However, the NP hard nature of the problem obscures the PN capability of reasoning about the behavior of the system. In this paper, two techniques to alleviate this drawback are presented: a systematic method to avoid the generation of futile paths within the search graph and a novel hybrid stage-search algorithm. The new algorithm is based on the application of guided by a PN-based heuristic within a limited local search frame. An optimization policy is applied to maintain, under evaluation, only the most promising paths. For each system state, the algorithm is able to decide whether an enabled operation should be applied and to maintain this decision until new information forces reconsideration. This eliminates permutation paths and useless scheduling sequences. Experimental results show that the algorithm's cost does not grow exponentially with the size of the problem. Comparison with previous work is given to show the superiority of our approach and the potential of PN-based heuristic search.

An integrated modeling approach for shop-floor scheduling and control problem of flexible manufacturing systems

“…CPN models of the FMS's object classes are developed based on the previous study by Tuncel and Bayhan [22] (see Figs. 5,6,7,8). A summary of data/attributes and operations/methods of the object classes is listed in Tables 2, 3, 4, 5.…”

“…Flexibility and quick response to the changes in demand are major advantages of the proposed methodology. Many researchers have employed PNs for scheduling and control of manufacturing systems [6][7][8][9][10][11][12][13][14]. However, Petri-net-based dynamic scheduling of FMSs dealing with production of several product types with flexible routes, setup times, material handling system, and operator constraints has not been given much attention [15].…”

Scheduling a Life Science High-Throughput Platform under Starvation Constraints Using Timed Transition Petri Nets and Heuristic Search

“…Terminology of Timed Transition PN As a graphical and mathematical tool, PN provides a uniform environment for process modeling, formal analysis, and design of discrete event systems [10,11]. It also provides a good platform for process scheduling [4,[7][8][9][12][13][14][15].…”

“…The results show that HCH (Hong-Chow-Haaland) algorithm can be used to find the optimal solutions. HCH algorithm is more efficient than L1 algorithm [7] and most other generic A* extended algorithms [8,9] when applied to the transition variant Petri nets (TVPN) models. This paper is organized as follows: Section II introduces the procedure and constraints of the high-throughput platform and describes the timed transition PN modeling for scheduling; Section III introduces the TVPN and describes the HCH scheduling algorithm used for PN searching; Section IV presents two case studies and the scheduling results.…”

Ga based approach for optimized scheduling in a semiconductor wafer fabrication

“…It has its own production style and scheduling characteristics, such as large-scale, reentrance, mix processing model and unbalanced production facilities [1], [2]. As a result, it is difficult to directly apply successful scheduling methods in job shop and flow shop to semiconductor wafer fabrication 1 .…”