Simultaneous Scalable-Reconfigurable Manufacturing System Design and Inventory Control Policy Decision Making

Author(s):  
J. Patrick Spicer ◽  
Hector J. Carlo

Scalable reconfigurable manufacturing systems (scalable-RMS) consist of standardized modular equipment that can be quickly added or removed to adjust the production capacity. Each modular machine, referred to as a scalable reconfigurable machine tool (scalable-RMT), is composed of identical modules that can be added to, or removed from the machine depending on its required throughput. In previous work, conceptual scalable-RMTs have been described. Additional scalable-RMTs are presented in this paper to highlight the applicability of this concept in manufacturing. As an extension to existing scalable-RMS literature, this paper incorporates multiple products in the system configuration design. Specifically, this paper proposes an integer programming based iterative algorithm for finding the minimum cost configuration of a multi-product system. It is shown that the proposed algorithm converges to the optimal solution under the majority of practical conditions. Then, a mathematical formulation to minimize the system investment and operational costs in a multi-product scalable-RMS is presented. A numerical example compares the solution obtained using the traditional approach of determining the system design and then the inventory control policy versus the proposed simultaneous approach. It is concluded that the simultaneous approach yields significant improvement over the traditional (decoupled) approach.

Author(s):  
Hector J. Carlo ◽  
J. Patrick Spicer ◽  
Adamaris Rivera-Silva

The design of manufacturing systems is typically decoupled from ordering policy decisions. Traditionally, the system design decision is made to minimize the total investment cost given some system capacity requirements. Then, after the system is implemented, the ordering policy decisions are made. In this paper, a coupled approach is presented whereby the manufacturing system design is jointly developed with the ordering policy to minimize the total cost of inventory holding, setup, and equipment investment in a multiproduct system. The methodology is presented in the context of scalable-reconfigurable manufacturing systems (scalable-RMSs). First, a linear integer mathematical formulation to minimize investment cost in a single-product, multistage scalable-RMS is presented. The mathematical formulation is then extended to consider multiple products. Due to the nonlinear nature of the multiproduct formulation, an iterative algorithm is developed. Lastly, a mathematical formulation to simultaneously minimize the system investment and operating costs (i.e., the coupled approach) is presented. Given the complexity of the formulation, a genetic algorithm (GA)-based heuristic is proposed. Twenty four instances of the problem were generated to test the proposed methodologies. Experimental results indicate that the proposed GA-based heuristic is efficient in terms of solution quality and runtime. Further, experimental results indicate that the proposed coupled approach reduces the total costs by an average of 25% over the decoupled approach. It is concluded that the coupled approach (solved with the proposed GA-based heuristic) outperforms the decoupled approach (solved to optimality) in all instances considered.


Author(s):  
Martha Purnama Sari Panggabean ◽  
Dimas Akmarul Putera ◽  
Nursafwah

PT. XYZ adalah perusahaan yang bergerak didalam pembuatan kemasan botol minum. Pendistribusian produk dilakukan PT XYZ menggunakan data historis berdasarkan jumlah permintaan pada tahun 2013 dan 2014. Data tersebut menunjukkan bahwa terjadinya perbedaan hasil. Tahun 2013 memiliki jumlah permintaan yang lebih rendah dari tahun 2014. Informasi terdapat bahwa perlu dilakukan pengevaluasian karena didalam rantai produksi terdapat bullwhip effect. Terdapat nilai bullwhip Effect menujukan bahwa nilai bullwhip effect untuk distributor Indomaret, Carrefour, dan rantai manufakturnya masing-masing sebesar 0,5303; 0,2967, dan 0,5114. Usulan perbaikan dapat diatasi yaitu dengan model Q yang berfungsi menggendalikan persediaan pada rantai pasok dengan metodeHadley-Within. Perhitungan pengendalian persediaan untuk distributor Indomaret, Carrefour, dan rantai manufakturnya masing-masing sebesar 1,0721; 1,100; dan 1,0714. Hasil dari perhitungan menujukan bahwa terjadi keseimbangan antara penjual dan pembeli sehingga biaya pun dapat dihematkan pada PT XYZ.   PT. XYZ Medan is manufacturing company that produce soft drinks of beverages in containers. In the product distribution system at PT. XYZ Medan, found that the number of orders based on the result of forecasting in 2013 lower than actual orders at distrbutor and manufacturer in 2014. Distorsion of information on this order can evaluate the indication of bullwhip effect in supply chain. Based on the result calculation of bullwhip effect, found that the value of bullwhip effect for Indomaret distributor, Carrefour, and supply chain of manufacturer each of 0,5303; 0,2967, and 0,5114. Proposed improvements to predominate bullwhip effect that is by doing inventory control policy with Q model using Hadley-Within approach. The value of bullwhip effect aftre doing inventory control policy for Indomaret distributor, Carrefour, and supply chain of manufacturer each of 1,0721; 1,100; dan 1,0714. The value of bullwhip effect which is close to one shows that the variance between the number of the order and the number of the demand nearly balanced so as to save the inventory cost at PT. XYZ Medan.


2019 ◽  
Vol 8 (2) ◽  
pp. 195-206 ◽  
Author(s):  
Ashutosh Singh ◽  
Mohammad Asjad ◽  
Piyush Gupta ◽  
Jahangir Quamar

The traditional structure of machines (such as lathe, milling, shaper, slotter, drilling and planer) has become questionable because of the modular concepts (such as modularity, scalability, convertibility, mobility and flexibility) and reconfiguration becomes a promising approach towards modular manufacturing machines, in which manufacturing techniques are independent of changes. In this area, reconfigurable machine tool (RMT) forms a new class of modular machines in current manufacturing scenario where the manufacturing industry put a strong pressure on good quality and price reduction. The capabilities of the machines tool and manufacturing systems in reconfigurable manufacturing system (RMS) change with each reconfiguration (both software and hardware modules). In this case, an approach is presented for reconfiguration of horizontal shaper machine for developing the modular shaper cum slotter machine in a manufacturing system by adding some auxiliary (like Scott Russel mechanism) and some basic modules and the reconfiguration features of traditional shaper and slotter machine are also discussed. The proposed approach is illustrated with a figure, which has been designed on 3-D design tool (solid-works software platform). It is expected that, this work will help designers and practising engineers by making them aware of the reconfiguration mechanisms on traditional shaper machine, which have become a necessity for the very survival of manufacturing by lowering the operational costs.


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