Browsing by Subject "Pull Systems"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    ItemOpen Access
    Design and analysis of just-in-time production systems
    (1988) Oğuz, Ceyda
    Just-in-Time (JIT) production systems have initially appeared in the Japanese manufacturing environment due to the scarcity of their critical resources. The main aim in JIT production systems is to eliminate waste. To achieve this objective, setup times, lead times, in-process inventories, and defective production must all be minimized. In the design process of a JIT production system, several factors such as lot size, number of kanbans, unit load size, and buffer capacities must be taken into account. In this study, a mathematical model is developed for a single-item, single-line, multi-stage, and multi-period JIT production system. The original model is nonlinear in both objective function and constraints. To reduce the computational difficulties, the nonlinear model is then approximated by a linear model. Next, a simulation model is developed to incorporate the stochastic nature of the demand. A sensitivity analysis is performed on unit load size and on buffer capacity under different demand patterns to examine their effects on the behavior of the model. The results show that thofee unit load size values exceeding 10 percent of the maximum demand in the planning horizon have no effect on the model.
  • Thumbnail Image
    ItemOpen Access
    Serial production lines under pull environment
    (1996) Eskigün, Erdem
    Uie aim of this thesis is to evaliuite the performance of transfer lines under pull environment. In this study, we have modelled a two-stage trcuisfer line separated by finite buffers by using Markov-Chcun representation. Experiments with different parameters were carried out to evaluate the different performance measures of the system. A two-stage simulation model was also constructed by using the package PromodelPC 2.0. Since two-stage models are limited to analyze most prcictical systems in manufacturing, we have extended it to an N-stage model. From the experiments performed for both two-stage and Nstage models, we hcive observed that we can decreci.se the in-process inventory substantially by just exchanging the positions of the nicichines in the system. Assembly-disassembly systems under pull environment have also been modelled by using simulation.