First it is clarified that in ordinary Petri Net model, sequential conflict exists on the level of place, token and transition respectively, which can be resolved by introducing appropriate priority scheduling rules;
A kind of hybrid heuristic genetic algorithm is introduced for the job shop problem n/m/G/C max , in which the scheduling rules of SPT and MWKR are applied, and the neighbourhood search technique (NST) is adopted as an auxiliary procedure to improve the solution performance.
A system prototype is realized for middle and little batch production scheduling by Visual Foxpro5.0, Siman3.51, Powerbuilder5.0 and Matlab4.0. It includes Optimization-simulation subsystem, Dispatching rule selecting subsystem and Evaluating subsystem.
Based on the effect of dispatching rule and traffic management method on system performance, a mathematical model was put forward, with which the number of vehicles that an AGVS needs can be easily evaluated.
Taken the weather system and rainfall intension into consideration, the classified dispatching rules are determined for reservoir forecasted flood operations through regulating the forecasted floods with different weather systems.
In order to validate the method and compare and evaluate the new combinatorial dispatching rule, a simulation method is presented, then seven dispatching rules proposed in literatures and RAN(FCFS,ODD) are adopted in scheduling simulation. Simulation results indicate that the heuristic method is effective and RAN(FCFS,ODD) outperforms the other seven dispatching rules with respect to the dynamic job shop scheduling problem proposed.
Based on summarization of the state-of-the-art researches on scheduling for batch processing machines of semiconductor wafer fabrication facilities, the scheduling rule for batch processing machines in semiconductor wafer fabrication facilities (SRB), considering future arrival lots and workloads of their successive machines, was proposed.
在综述批加工设备调度研究成果的基础上,提出了同时考虑即将到来工件与下游设备负载情况的半导体生产线批加工设备调度规则(Scheduling Rule for Batch Processing Machines in Semiconductor Wafer Fabrication Facilities,SRB)。
7. One method which can obtain best scheduling rule set in specific manufacture environment is proposed, genetic algorithm and process simulation is integrated in this method, process simulation is used to get adaptive function value and genetic algorithm is used to search optimum solution.
Through a simulation study, the performance of the method is compared with that of a popular dispatching rule.
When the first-come-first-served dispatching rule is used, we derive the relationship between the number of stations and the ratio of the average cargo retrieval time to the average cargo storage time.
When the first-encountered-first-served dispatching rule is used, we show that even the arrangement of the input channel and the output channel of a station can have significant impact on the cargo waiting time.
The results show that the proposed algorithm optimally solves most cases of the ONO scheduling problem in real settings and significantly outperforms dispatching rule-based heuristics.
The real-time scheduling deals with the small-effort change of the system with a real-time dispatching rule.
This method can be applied to optimize problems with any type of variables (variables from a real set, e.g., conveyor speed; an integer set, e.g., size of buffer; or any general set, e.g., dispatching rules).
On-line optimal dispatching rules, which consider only available - as opposed to look-ahead - information, are developed.
The model uses a discrete-time Markov chain based on vehicle location and represents dispatching rules in the one-step transition matrix.
The performance of the algorithm is compared with several machine and AGV dispatching rules using mean flow time, mean tardiness and makespan criteria.
The results indicate that the proposed scheduling algorithm yields considerable improvements in system performance over dispatching rules under a wide variety of experimental conditions.
The proposed PCS chooses periodically, on the basis of the current state of the system, the most appropriate scheduling rule, out of several predetermined ones.
The proposed PCS is based on multi-layer NNs, one for each competing scheduling rule, that predict the FMC's performance.
In the present paper, we study an extension of the MOD rule using job-waiting-time based discrimination among operationally late jobs to protect long jobs from excessive delays by incorporating an 'acceleration property' into the scheduling rule.
This situation is encountered when the low volume products can be managed with an MTO policy under the PR scheduling rule, while they have to be managed according to an MTS policy under the FIFO scheduling rule.
This paper presents an Estimation of Distribution Algorithm (EDA) for the nurse scheduling problem, which involves choosing a suitable scheduling rule from a set for the assignment of each nurse.