《系统工程》课程教学资源（英文文献）Network design based on closed-loop reverse logistics recycling

Network Design Based on Closed-loop Reverse Logistics RecyclingAbstract-With the people's attention to the product qualityin meeting the challenges presents a formidable advantagetheenvironmentalprotectionandconsciousnessnot easily replicable by its competitorsenhancement,thereverselogisticsstarttocausecontinuously attention of people. More and more scholarsI1.MODELASSUMPTIONSONCLOSED-LOOPNETWORKresearch the origin, the concept, the classification oftheIn order to facilitate the establishment ofthe closed loopreverse logistics. At present there are some researches of thereverse logistics model, thefollowing assumptions:reverse logistics, however, these researches are restricted onlyThere is only a recall of defective products. Theyin the theory, and are few to the practical application research.In the process of the engineering to the implementation ofareknownto determinefor recyclingdefectiveenterprise reverse logistics, we must grasp its essence, carry onproducts,processingcapacityofdismantlingcenterthe analysis and the design based on this foundation, so it can,as well as investment costs and operating expensesguarantee the reverse logistics system running highlyof the facilities, the cost of transport between theeffectively and accurately.This paper presents solutions tofacilities,closed-loop network designing based on the traditionalWe consider only a part cost of reverse logisticsdesigning for logistics facility location and capacity allocationnetwork, that is thetotal cost from therecovery pointmodel and combined with characteristics of reverse logistics.to thenewcenterfor dismantling (or the expansionAn optimization model is replied on linear programming andof the original distribution center) to the newthe objective is to minimize the sum of investment andprocessing plant (orthe expansion of the originaloperation costs of logistics facilities as well as transportationfactory).Without taking into consideration costs ofand environment protection costs of returned products amongthe product restored,once again distribution, andthe facilities. To explain the method for the network offacilitymarketing,location and capacity allocationby the model, an example isThe recall of defective products in recovery point arepresented.all shipped to dismantling center,All repairableproducts after testing in theKeywords-Closed-loop,ReverseLogistics,Reverse Logistidismantling center are all shipped to processingRecyling,NetworkDesiplants;Notto considerprocessingproblemof beyond1.INTRODUCTIONrepairproducts,The goal of manufacturing enterprises is to ship goodsWe consider only the establishment of dismantlingthrough their plants to their customers. This movement ofand processing center in theknown location ofanumber place,goods most often means a profit to all involved. These samecompanies, however,do not want products to be returnedThe recovery amount of recalled product arefor any reason.They do not plan for the backwardcalculated by region, and it is in direct proportion tomovementorreturnofgoods,knownasreverselogistics,asconsumption intheregion,thesereturns represent asubstantial costratherthanaprofit.III.THEAPPLICATIONSONCLOSED LOOPNETWORKSome CEO's even perceivereturned goods as a failure oftheir system.Based on forward logistics network, the topology ofSometimes reverse logistics is regarded as a recyclingclosed-loop network is analyzed. An optimization modelprocess involving,papers,plastic and glass.A well-replying on mixed integer linear programming (MILP) is setmanaged RL network cannotonly provide important costup for designing closed-loop reverse logistics network. Thesavings in procurement, recovery, disposal, inventoryobjectivealsoistominimizethesumofinvestmentandholdingand transportation but also help in customeroperationcostsoffacilitiesaswell astransportationcostsretention. Since RL operations and the supply chains theyof returned products among the facilities. And the end wesupport are significantly more complex than traditionalalso analysis an example. Because reverse logistics channelsmanufacturing supply chains, an organization that succeedsare different with forward logistics channels, the integrationof thetwo channels is unlikely.So we will build an

Network Design Based on Closed-loop Reverse Logistics Recycling Abstract—With the people's attention to the product quality and the environmental protection consciousness enhancement, the reverse logistics start to cause continuously attention of people. More and more scholars research the origin, the concept, the classification of the reverse logistics. At present there are some researches of the reverse logistics, however, these researches are restricted only in the theory, and are few to the practical application research. In the process of the engineering to the implementation of enterprise reverse logistics, we must grasp its essence, carry on the analysis and the design based on this foundation, so it can guarantee the reverse logistics system running highly effectively and accurately. This paper presents solutions to closed-loop network designing based on the traditional designing for logistics facility location and capacity allocation model and combined with characteristics of reverse logistics. An optimization model is replied on linear programming and the objective is to minimize the sum of investment and operation costs of logistics facilities as well as transportation and environment protection costs of returned products among the facilities. To explain the method for the network of facility location and capacity allocation by the model, an example is presented. in meeting the challenges presents a formidable advantage not easily replicable by its competitors . II. MODEL ASSUMPTIONS ON CLOSED-LOOP NETWORK In order to facilitate the establishment of the closed loop reverse logistics model, the following assumptions:  There is only a recall of defective products. They are known to determine for recycling defective products, processing capacity of dismantling center ,as well as investment costs and operating expenses of the facilities, the cost of transport between the facilities;  We consider only a part cost of reverse logistics network, that is the total cost from the recovery point to the new center for dismantling (or the expansion of the original distribution center) to the new processing plant (or the expansion of the original factory).Without taking into consideration costs of the product restored ,once again distribution, and marketing;  The recall of defective products in recovery point are all shipped to dismantling center; Keywords-Closed-loop, Reverse Logistics, Reverse Logistics Recycling, Network Design  All repairable products after testing in the dismantling center are all shipped to processing plants; I. INTRODUCTION  Not to consider processing problem of beyond repair products; The goal of manufacturing enterprises is to ship goods through their plants to their customers. This movement of goods most often means a profit to all involved. These same companies, however, do not want products to be returned for any reason. They do not plan for the backward movement or return of goods, known as reverse logistics, as   We consider only the establishment of dismantling and processing center in the known location of a number place; The recovery amount of recalled product are calculated by region, and it is in direct proportion to consumption in the region; these returns represent a substantial cost rather than a profit. Some CEO’s even perceive returned goods as a failure of their system. Sometimes reverse logistics is regarded as a recycling process involving, papers, plastic and glass. A well￾managed RL network cannot only provide important cost savings in procurement, recovery, disposal, inventory holding and transportation but also help in customer retention. Since RL operations and the supply chains they support are significantly more complex than traditional manufacturing supply chains, an organization that succeeds III. THE APPLICATIONS ON CLOSED LOOP NETWORK Based on forward logistics network, the topology of closed-loop network is analyzed. An optimization model replying on mixed integer linear programming (MILP) is set up for designing closed-loop reverse logistics network. The objective also is to minimize the sum of investment and operation costs of facilities as well as transportation costs of returned products among the facilities. And the end we also analysis an example. Because reverse logistics channels are different with forward logistics channels, the integration of the two channels is unlikely. So we will build an

independent networkofrecoveryTheestablishmentofproducts are completed mainly in the dismantlingnetworks can berecovered items as rawmaterial inputs ofacenter. Processing plants not only will recyclingtraditional supply chain.As long as we modify networkplant products, materials used in reproduction,model oftheforward logistics,itcanbeusedfor reverseproductionmay also be used to add some newlogistics network:products in short supply.Whatistherelationshipbetweenforward channelsA.TheConstructionofClosedLoopNetworkfor logistics and reverse logistics channels?Closed-loop network means mainly that recycling theIV.ESTABLISHMENT OF MODEL ON CLOSED-LOOPproduct or packaging materials back to the originalNETWORKmanufacturer. Closed-loop apply reverse logistics networksuch as the re-manufacturing, commercial return or re-use.The closed-loop network structural drawing based on reverseModelParameters.logisticssystemofrepairableproductsshowninFig.1Ai-said recovery amount of defective products inregional i,fj-said thefixed costs ofnewcenterfor dismantlingWaste DisposalExternal(ortheexpansionoftheoriginal distributioncenter);Vi-saidthe unit cost ofoperation ofnew centerforsod g kisdismantling (or the expansion of the originalCnKoau pooa pegienoaadistribution center),aad edaerepdstij-saidtheunitcostoftransportfrom therecoveryaodaienepoint of products to new center for dismantling (orthe expansion of the original distribution center);Jain-said theminimumprocesing capacityofnewcenterfor dismantling (or the expansion of theoriginal distribution center),Jsaidthemaximumprossingcapacityofnewcenter for dismantling (or the expansion of theAfterconmers useoriginal distribution center),fr-said the fixed costs of new processing plants (or theVexpansionoftheoriginal plants);Forward logistiesrverse logisticsVe-said that the unit cost of processing of newprocessing plant (or the expansion of the originalFigure.1. The closed-loop network structural drawing based on reverseplant),logistics system of repairable products.t-saidthatunittransportation costs of thenewcenterfordismantling (ortheexpansionoftheoriginaldistribution center)to the newprocessing plant (or6Thediscussing issues of closed loop networkthe expansion of the original plant)k,Recycling network layout ofclosed-loop should be basedK.i-saidtheminimum processing capacity ofnewon the target of low-cost, easy return. To discuss theprocessing plants (or the expansion ofthe originalfollowing issues:plants) to defective products;K--said the maximum processing capacity ofnewWhich enterprise members do constitute reverseprocessing plants (or the expansion oftheoriginallogisticssystem?Reverselogisticssystemincludeplants)to defective products;the members the former logistics channels(such asm-said thelargest number of thenew centerformanufacturers,distributors,logisticsservicedismantling,providers, etc.)as well as other service providersn-said the largest number of new processing plant,(such as dealers in the secondary market,recyclingo-saidminimumwastedisposalrateofthematerials handling business, etc.).dismantling center (each treatment plant are theWhat function must have reverse logistics system?same).(such as the collection, classification,transportationdemolition, repair or disposal).Where do theyDecision-making Variable4achieve?Collectiondefectiveproductsarexij -said the number of the defective products in thecompleted mainly in the recovery point, Testing,collection point to the dismantling centers;dismantling,sorting and abandoned processingxjk-said the defective product number from the

Repairable product inventory Assembly manufacturing process Qualified goods inventory Demand for new products Product recall Repair process Check、test independent network of recovery. The establishment of networks can be recovered items as raw material inputs of a traditional supply chain. As long as we modify network model of the forward logistics, it can be used for reverse logistics network: products are completed mainly in the dismantling center. Processing plants not only will recycling plant products, materials used in reproduction, production may also be used to add some new products in short supply. A. The Construction of Closed Loop Network Closed-loop network means mainly that recycling the product or packaging materials back to the original manufacturer. Closed-loop apply reverse logistics network such as the re-manufacturing, commercial return or re-use. The closed-loop network structural drawing based on reverse logistics system of repairable products shown in Fig.1. A.  What is the relationship between forward channels for logistics and reverse logistics channels? IV. ESTABLISHMENT OF MODEL ON CLOSED-LOOP NETWORK Model Parameters Ai-said recovery amount of defective products in regional i; Waste Disposal External After consumers use fj- said the fixed costs of new center for dismantling (or the expansion of the original distribution center) ; vj -said the unit cost of operation of new center for dismantling (or the expansion of the original distribution center); tij -said the unit cost of transport from the recovery point of products to new center for dismantling (or the expansion of the original distribution center); Jmin -said the minimum processing capacity of new center for dismantling (or the expansion of the original distribution center); Jmax -said the maximum processing capacity of new center for dismantling (or the expansion of the original distribution center); fk - said the fixed costs of new processing plants (or the Forward logistics Reverse logistics vk expansion of the original plants) ; -said that the unit cost of processing of new Figure.1. The closed-loop network structural drawing based on reverse logistics system of repairable products. B. The discussing issues of closed loop network Recycling network layout of closed-loop should be based on the target of low-cost, easy return. To discuss the following issues: processing plant (or the expansion of the original plant); tjk -said that unit transportation costs of the new center for dismantling (or the expansion of the original distribution center) to the new processing plant (or the expansion of the original plant) k; Kmin-said the minimum processing capacity of new processing plants (or the expansion of the original plants) to defective products;   Which enterprise members do constitute reverse logistics system? Reverse logistics system include the members the former logistics channels(such as manufacturers, distributors, logistics service providers, etc.) as well as other service providers (such as dealers in the secondary market, recycling materials handling business, etc.). What function must have reverse logistics system? (such as the collection, classification, transportation, demolition, repair or disposal).Where do they achieve? Collection defective products are completed mainly in the recovery point; Testing, dismantling, sorting and abandoned processing B. Kmax-said the maximum processing capacity of new processing plants (or the expansion of the original plants) to defective products; m- said the largest number of the new center for dismantling; n - said the largest number of new processing plant; σ-said minimum waste disposal rate of the dismantling center (each treatment plant are the same). Decision-making Variable xij -said the number of the defective products in the collection point to the dismantling centers; xjk-said the defective product number from the

dismantling centers to processing plants;Bound formula (2)-said the recall of defective productsLj-said circulation of treatment plant,to the centerfor dismantling (ortheexpansion of theoriginal distribution centers),fiChoice of dismantling centerj:yiBound formula (3)-said the recall of defective products0 Otherwise.to the treatment plant, a part of the waste disposed, and theother part as re-sale after processing,yr1 Choice of processing plant k,Bound formula (4) and bound formula (5)-said capacity0Otherwiseconstraints of distribution centers,Bound formula (6) and bound formula (7)saidprocessing capacity constraints in the processing plants;i- said the collection point,Bound formula (8) and bound formula (9)-said toj-said the new center for dismantling (or theprovide range for decision-making variables (Xii; Xj),expansion of the original distribution center)Bound formula (10) and bound formula (11)-said thek-said the new processing plants(or the expansion ofcandidate's limit on the number of points;the original plants),Boundformula(12)andboundformula(13)-saidtoC.The Objective Functionprovide range for decision-making variables (yi; yi),Em+e+a+MinZ-SSietexmuaE.ModelSolution(1The above model is a linear programming problem[9]The minimize costs of thefunction in the network is theWe can now use specialized mathematical software LINGOgoal. Including the cost:to solve their programming. LINDO is the Linear Interactiveand Discrete Optimizerprefix in theformof abbreviationsEo+EoLINDO is a computing software package developed byThefixed costs ofdismantling centers andLINDO System company. It can be used to solve linearprocessing plants;programming(LP), Integer Programming(IP), QuadraticProgramming(QP)problem.The next section of this articleSmtet osnosominwill cite a specific example.The use of methods to solve isin order to verify the validity of the model.centers and processing plants,V.CASE STUDY The transport costs,24The network has 6 recovered points, 5 candidate ofdismantling center,We consider the expansion oftheD.existing distribution center in J4,J5.J1,J2J3 is theConstraintscandidate of new dismantling center.We consider to buildtwo dismantling center, that is, m=2. The disposal rate of大Vi"Aminimum waste in dismantling center is 0.4.There are(2) four alternatives to processing plants, of which K1 K2 mayvj(1-SxSXA-0tobeconsideredtheexpansionofexistingplants,andK34(3)TK4 is a candidatefor the newplant,to consider tobuildavinew, that is, n=l,Specific data, such as thefollowing(4)TABLE.Vi(5) TABLELRECALL VOLUMEOF DEFECTIVE PRODUCTS OF COLLECTIONPOINTS (TONS)vi(6) Collection points13131415vj(7)Ai203080406030X,20Vi,j(8)vj,kTABLE II.THE MINIMUM AND MAXIMUM PROCESSING POWER OF THE(9)DISMANTLING CENTER TO DEFECTIVE PRODUCTS(TONS)Dismantling center(10)ProcessingAscapacityJhJ4Js(11)Ty,E(0.1]VtJo902025110120(12)vjy,e011(13)1551751305060Ja535

Processing capacity Dismantling center J1 J2 J3 J4 J5 Jmin 110 120 90 20 25 Jmax 155 175 130 50 60 Collection points I1 I2 I3 I4 I5 I6 Ai 20 30 80 40 60 30 dismantling centers to processing plants; Lj -said circulation of treatment plant; yj 1 Choice of dismantling center j; 0 Otherwise . yk 1 Choice of processing plant k; 0 Otherwise . i- said the collection point; j- said the new center for dismantling (or the expansion of the original distribution center) k -said the new processing plants(or the expansion of the original plants). C. The Objective Function Bound formula (2) - said the recall of defective products to the center for dismantling (or the expansion of the original distribution centers); Bound formula (3) –said the recall of defective products to the treatment plant, a part of the waste disposed, and the other part as re-sale after processing; Bound formula (4) and bound formula (5)–said capacity constraints of distribution centers; Bound formula (6) and bound formula (7)–said processing capacity constraints in the processing plants; Bound formula (8) and bound formula (9) –said to provide range for decision-making variables (xij;xjk); Bound formula (10) and bound formula (11) –said the candidate's limit on the number of points; Bound formula (12) and bound formula (13) –said to provide range for decision-making variables (yi;yj); (1) E. Model Solution The minimize costs of the function in the network is the goal. Including the cost: : The fixed costs of dismantling centers and processing plants; : The processing costs of dismantling centers and processing plants; : The transport costs; The above model is a linear programming problem[9]. We can now use specialized mathematical software LINGO to solve their programming. LINDO is the Linear Interactive and Discrete Optimizer prefix in the form of abbreviations. LINDO is a computing software package developed by LINDO System company. It can be used to solve linear programming(LP), Integer Programming(IP), Quadratic Programming(QP)problem.The next section of this article will cite a specific example. The use of methods to solve is in order to verify the validity of the model. V. CASE STUDY The network has 6 recovered points, 5 candidate of dismantling center. We consider the expansion of the D. Constraints (2) (3) (4) (5) existing distribution center in J4，J5 . J1，J2，J3 is the candidate of new dismantling center . We consider to build two dismantling center, that is, m=2. The disposal rate of minimum waste in dismantling center σ is 0.4. There are four alternatives to processing plants, of which K1 K2 may to be considered the expansion of existing plants, and K3， K4 is a candidate for the new plant, to consider to build a new, that is, n=1. Specific data, such as the following TABLE. TABLE I.RECALL VOLUME OF DEFECTIVE PRODUCTS OF COLLECTION POINTS (TONS) (6) (7) (8) (9) (10) (11) (12) (13) 535 TABLE II.THE MINIMUM AND MAXIMUM PROCESSING POWER OF THE DISMANTLING CENTER TO DEFECTIVE PRODUCTS(TONS)

TABLE II THE MINIMUM AND MAXIMUM PROCESSING POWER OF THETABLE VIIL.THE UNIT TRANSPORT COST FROM CANDIDATES OFPROCESSING PLANTS TO DEFECTIVE PRODUCTS(TONS)DISMANTLING CENTER TO PROCESSING PLANTS(YUAN)processing plantsDismantling centersProcessing capacityPlantsKiKsKsK4JiJJJJs5065145160KKi337114647205Kmr.95100220K2349162525K2240172010TABLE IV. THE FIXED COSTS AND UNIT OPERATING COSTS FOR THE13DISMANTLING CENTER(YUAN)Ks5451555Dismantling centecostsJiJJsJsVI.CONCLUSIONBy comprehensive analysis, we can draw that reversef120001500001000001000011000logistics system recycling network for the study. To carryouttheiroptimizingdesign,throughtherecyclingofused23212533353materials, recycling,energy recovery andre-manufacturingetc.To achieve thefollowing.To maximize the utilizationrate of resources, reduce consumption of resources, reduceproduction costs; To reduce environmental pollution,reduceTABLE V.THEFIXED COSTS AND UNIT OPERATING COSTS FOR THEPROCESSING PLANTS (YUAN)oravoid pollutionfines,toreducethecost ofpollutioncontrol and waste disposal costs;So that thebusinessProcessing plantscommunity has a better image for the business to addcostsintangibleassets.KiK2KsK423000310002100002300005ACKNOWLEDGMENT82877276yThis paper is subsidized by the Science Fund ofShandong Jiaotong University(Z200905).TABLE VI.THE UNIT TRANSPORT COST FROM RECOVERY POINTS TOCANDIDATESOF DISMANTLING CENTER (YUAN)recovery pointDismantling centerhI2b141sJ6Ji102533301611小59583729179J12461022505J17137133350Js3422462596

Dismantling center recovery point I1 I2 I3 I4 I5 I6 J1 10 25 33 30 16 11 J2 59 58 37 29 17 9 J3 12 46 10 5 22 50 J4 17 13 7 13 50 33 J5 34 22 46 9 6 25 Plants Dismantling centers J1 J2 J3 J4 J5 K1 11 33 46 47 7 K2 34 9 16 25 25 K3 22 40 17 20 10 K4 5 13 45 15 55 costs Processing plants K1 K2 K3 K4 fi 23000 31000 210000 230000 vj 87 82 72 76 costs Dismantling center J1 J2 J3 J4 J5 fi 120000 150000 100000 10000 11000 vj 23 21 25 33 35 Processing capacity processing plants K1 K2 K3 K4 Kmin 50 65 145 160 Kmax 95 100 205 220 TABLE III THE MINIMUM AND MAXIMUM PROCESSING POWER OF THE PROCESSING PLANTS TO DEFECTIVE PRODUCTS(TONS) TABLE IV. THE FIXED COSTS AND UNIT OPERATING COSTS FOR THE DISMANTLING CENTER(YUAN) TABLE VII.THE UNIT TRANSPORT COST FROM CANDIDATES OF DISMANTLING CENTER TO PROCESSING PLANTS(YUAN) VI. CONCLUSION By comprehensive analysis, we can draw that reverse TABLE V. THE FIXED COSTS AND UNIT OPERATING COSTS FOR THE PROCESSING PLANTS (YUAN) logistics system recycling network for the study. To carry out their optimizing design, through the recycling of used materials, recycling, energy recovery and re-manufacturing, etc. To achieve the following:To maximize the utilization rate of resources, reduce consumption of resources, reduce production costs; To reduce environmental pollution, reduce or avoid pollution fines, to reduce the cost of pollution control and waste disposal costs;So that the business community has a better image for the business to add intangible assets. ACKNOWLEDGMENT This paper is subsidized by the Science Fund of Shandong Jiaotong University(Z200905). TABLE VI.THE UNIT TRANSPORT COST FROM RECOVERY POINTS TO CANDIDATES OF DISMANTLING CENTER (YUAN)