Browsing by Subject "Reactive Scheduling"

Now showing 1 - 3 of 3

Open Access
Analysis of reactive scheduling problems in manufacturing systems
(1997) Bayız, Murat
In this study we develop a new scheduling algorithm for the job shop problem. The proposed algorithm is a heuristic method based on the filtered beam search. After extensive analyses on the evaluation functions and search parameters of the beam search, we measure the performance of the algorithm in terms of quality of solutions and CPU times for both the makespan and mean tardiness criteria. In the second half of the research, we study the reactive scheduling problem. Specifically, we analyze several reactive methods such as no response, periodic response and continuous response under various experimental conditions. The beam search based partial scheduling is also studied in this thesis. The method is analyzed for both deterministic and stochastic environments under several job shop configurations.
Open Access
Analysis of scheduling problems in dynamic and stochastic FMS environment : comparison of rescheduling polices
(2001) Kızılışık, Ö Batuhan
In this thesis, we study the reactive scheduling problems in a dynamic and stochastic flexible manufacturing environment. Specifically, we test different scheduling policies (how-to-schedule and when-to-schedule policies) under process time variations and machine breakdowns in a flexible manufacturing system. These policies are then compared with on-line scheduling schemes. The performance of the system is measured for the mean flowtime criterion. In this study, a beam search based algorithm is used. The algorithm allows us to generate partial or full schedules. The results indicate that on-line scheduling schemes are more robust than the off-line algorithm in dynamic and stochastic environments.
Open Access
Reactive scheduling in cellular manufacturing systems
(1993) Görgülü, Elif
A real-time scheduling problem, specifically rescheduling under machine breakdowns, is considered in this thesis. A heuristic approach is developed for a manufacturing cell with a modified flow shop structure. The strategy reschedules part of the initial schedule to match up with the preschedule at some point. In contrast to other studies, the objective is to create a new schedule that is consistent with the other production planning decisions like material flow and purchasing by utilizing the time critical decision making concept. In the proposed heuristic approach, a new rescheduling strategy is developed and different match-up points are defined for each machine in order to maximize the flexibility during rescheduling. It is compared with alternative reactive scheduling methods in an experimental design and significance of some factors are tested by analysis of variance tests.