uses fuzzy logic to model delay ratio and identify the effect of delay changing to ...
The result of initial fuzzy logic model gives MSE and PME value is 2.41E-5 and.
ABSTRACT Supply activity is one of activities involved in manufacturing system in order to achieve customer satisfaction by supplying parts or products to all organizations level in supply chain. Coordination of managing inventory system among the organizations is one of the motivation for developing integrated inventory model. The final aim of this research are to minimize the total cost caused by holding inventory in warehouse and maintain long term relationship among the organizations. Common problems occur in integrated inventory are demand and lead time uncertainty. This research proposes the development of integrated inventory model by adding delay ratio caused by non productive time in vendor production process, whereas delay times is the part of lead time that consist of moving, waiting, and queuing time. This proposed model uses fuzzy logic to model delay ratio and identify the effect of delay changing to total cost. The result of initial fuzzy logic model gives MSE and PME value is 2.41E-5 and 22.513% respectively. Fuzzy logic model optimization is conducted using branch and bound technique by optimizing weight of fuzzy rule consequent. The MSE and PME after optimization are reduced into 8.96E-8 and 1.170% respectively. Optimal total cost of integrated inventory is obtained by applying solution procedures. The optimum result of total cost is Rp. 857,326.25, while quantity (Q) is 1147, and shipment frequency (n) is 7 at delay 0.0096. Delay prediction calculation is conducted to check fuzzy logic model validation and the result shows the MSE and PME value 2.41E-7 and 2.20% respectively. The development of integrated inventory model is useful to respond lead time uncertainty particularly uncertainty due to internal production process. Keywords: Lead time, Non productive time, Delay, Fuzzy Logic, and Integrated Inventory model
