The control of integrated manufacturing systems is usually complex with a huge number of interrelationships between cells. One approach that can accommodate such complexity is modeling the manufacturing processes on a computer, instead of going on the actual working environment. Furthermore the modeling and examination of coordinated manufacturing systems have turned out to be progressively imperative since the wide acknowledgment of ideas for various leveled control and processing plant robotization. The primary objective of any company is to produce products with low cost and high quality. Parameter optimization plays an important role in achieving this goal. Process parameter optimization in a cost bases usually involves the optimal selection of extrusion rate, setup time, feed rate, and capacity of the loading station. Besides, the use of computer simulation have been proposed and executed to tackle the issues of manufacturing cost reduction. A simulation model just goes about as an instrument in analyzing execution. It is basically a trial and error strategy, and does not specifically give clarifications to watched framework practices. Even though preceding studies of this area demonstrate that the outcomes of simulation can be used for further investigation of design of experiment, investigation of optimum manufacturing process parameter to reduce the cost of manufacturing for a product did not receive comparable attention. Therefore, this paper deals with the optimization of process parameters in a manufacturing system to minimize the Unit Manufacturing Cost (UMC) of Un-plasticized Poly Vinyl Chloride (UPVC) pipes using a combined Simulation–Robust Taguchi approach. With the new perspectives of integrated modeling, the study contributes to the body of knowledge which also opens a new outlook for further studies. Taguchi design of experiment is systematically approached for managing this study and L27 orthogonal array was selected for undertaking the simulation experiment. Thus significant factors along with their optimum combination were found using Taguchi techniques to arrive at the least manufacturing cost. The results show that these methods can be useful in reducing the number of experimental trials (only 36 simulation runs have been used) needed to determine the best operating parameters. The results of the work show that key parameters for optimum performance of the system are feed rate Evaluation and Optimization of Process Parameter Using Simulation- Taguchi Approach A unique approach in extrusion process of plastic industries viii FMIE- ©2018 (the entities per arrival) in to the hopper and the optimization of the extruder, The predicted unit cost of manufacturing the selected pipe model is 239 birr and predicted cost of manufacturing decreased by 21.6%., because the utilization of the resources increased by 13%, 19% for the worker from the actual performance.. As part of the general outcome of this study Taguchi method is helpful for reduction of unit manufacturing cost (UMC) and quality loss ($) respectively through incorporating ideas either at the product development or process design stage and also identifying optimum control parameter combinations. The outcomes can uncover that this approach can take into account the assessment and advancement of working conditions in complex frameworks at the same time.