LOGISTICS AND SUPPLY CHAIN CONFERENCE | Year:2012 | دوره:5 |Papers Count:16

THE LOCATION ROUTING INVENTORY PROBLEM (LRIP) INVOLVES SELECTING CENTRAL DEPOTS FROM A SET OF CANDIDATES AND DESIGNING A SET OF ROUTES FOR EACH DEPOT TO SERVE CUSTOMERS, WHILE MINIMIZING TOTAL DISTRIBUTION AND INVENTORY COSTS. IN ORDER TO CONSIDER OTHER DECISION FACTORS BESIDE COST AND MAKE THE PROBLEM MORE PRACTICAL, MULTI OBJECTIVE APPROACHES SEEMS TO BE USEFUL. THIS STUDY CONSIDERS THE TIME INTERVALS THAT CUSTOMERS MUST BE SERVED KNOWN AS HARD TIME WINDOWS, THE TIME INTERVALS THAT THE CUSTOMERS LIKE TO BE SERVED KNOWN AS SOFT TIME WINDOWS AND ALSO THE MODEL CONSIDERS AVOIDING UNDERUTILIZATION OF VEHICLES CAPACITY AND LABOR. WE ARE GOING TO INVESTIGATE THE USE OF GOAL PROGRAMMING APPROACH TO MODEL THESE PROBLEMS.

THIS STUDY PRESENTS A FUZZY MATHEMATICAL MODEL FOR A DISTRIBUTION NETWORK DESIGN PROBLEM IN A MULTI-PRODUCT SUPPLY CHAIN MANAGEMENT THAT CONTAINS LOCATING PRODUCTION PLANTS AND DISTRIBUTION CENTERS AS WELL AS DETERMINING THE BEST STRATEGY FOR DISTRIBUTING THE PRODUCT FROM PLANTS TO WAREHOUSES AND FROM THE WAREHOUSES TO CUSTOMERS WITH TRIANGULAR AND TRAPEZOIDAL MEMBERSHIP FUNCTIONS FOR CUSTOMER DEMANDS. FURTHERMORE THE MODEL DETERMINES THE CAPACITIES LEVEL OF THE FACILITIES (PLANTS OR DISTRIBUTION CENTERS (DCS)) AND THE DESIGN OF THE NETWORK (SELECTING THE OPTIMUM NUMBERS AND LOCATIONS OF PLANTS AND DISTRIBUTION CENTERS TO OPEN, SO THAT ALL UNCERTAIN CUSTOMER DEMANDS OF ALL PRODUCT TYPES ARE SATISFIED) WITH A MINIMUM TOTAL COST. IN THIS STUDY WE DEVELOP A FUZZY MIXED-INTEGER NON-LINEAR MATHEMATICAL PROGRAMMING MODEL FOR DESIGNING A SUPPLY CHAIN DISTRIBUTION NETWORK AND PRESENT A CASE-STUDY OF IRAN TO SHOW THE SUPERIORITY AND EFFICIENCY OF THE MODEL FOR A LARGE DAIRY COMPANY AND SOLVE IT BY A PROFESSIONAL SOFTWARE PACKAGE (LINDO).

IN TYPICAL SUPPLY CHAIN, DIFFERENT ECHELONS SUCH AS SUPPLIERS, MANUFACTURERS, DISTRIBUTORS, RETAILERS AND FINALLY CUSTOMERS ARE INVOLVED. IN MAKE-TO-ORDER SUPPLY CHAIN, THE MAIN FOCUS OF DECISIONS IS ON MANUFACTURING CENTERS. FOR A SUPPLY CHAIN TWO OFTEN CONTRADICTORY FEATURES I.E. "EFFICIENCY" AND "RESPONSIVENESS" COULD BE CONSIDERED WHICH USUALLY ARE TRANSLATED AS COST MINIMIZATION AND ONTIME DELIVERY CONSECUTIVELY. IN THIS PAPER, THESE TWO FEATURES IN MAKE-TO-ORDER MANUFACTURER ARE STUDIES VIA AN INTEGRATED MATHEMATICAL MODEL SIMULTANEOUSLY. THE OBJECTIVE OF THE PROPOSED MODEL IS TO SELECT THE BEST SUPPLIER NETWORK AND FIND THE BEST SEQUENCE OF PRODUCTION IN MAKE-TO-ORDER MANUFACTURER. SINCE THE PROBLEM IS NP-HARD, USING SIMULATED ANNEALING (SA) ALGORITHM IN WHICH INITIAL SOLUTION GENERATION AND NEIGHBORHOOD SEARCH IS BASED ON GRAPH-THEORETIC HEURISTIC THE PROBLEM IS SOLVED AND THE OBTAINED RESULTS ARE COMPARED TO THE RESULTS ACHIEVED BY CPLEX 10.1 SOFTWARE. THE COMPARISON SHOWS THAT SA GIVES QUALITY RESULTS IN REASONABLY SMALL RUN TIME.

IN THIS PAPER, ONE OF THE MODELS OF INVENTORY CONTROL PROBLEM IS INTRODUCED. THE MODEL HAS WAREHOUSE AND BUDGETARY CONSTRAINTS. IN WAREHOUSE CONSTRAINT, THE PARAMETERS ARE FUZZY TRIANGULAR NUMBER WHILE, IN BUDGETARY CONSTRAINT, AVAILABLE TOTAL BUDGETARY CAPITAL IS FUZZY RANDOM VARIABLE.CONSIDERING THE POSSIBILITY LEVELS, CONSTRAINTS ARE DEFUZZIFIED. THE BUDGETARY CONSTRAINT IS CONVERTED TO CRISP ONE WHICH IS NEITHER FUZZY NOR STOCHASTIC BY THE CHANCE-CONSTRAINED PROGRAMMING APPROACH. FINALLY, WE HAVE AN OPTIMAL CONTROL PROBLEM WITH TWO CRISP CONSTRAINTS WHICH IS SOLVED BY THE PONTRYAGIN MINIMUM PRINCIPLE AND KHUN-TAKER CONDITIONS. THE MODEL HAS BEEN ILLUSTRATED BY NUMERICAL EXAMPLE.

THIS PAPER ADDRESS THE DEVISING AN INTEGRAL LOGISTICS NETWORK FOR A REAL LIFE CASE OF A CAR INDUSTRY IN IRAN CALLED SAIPA GROUP BY CONSOLIDATING THE TRANSPORTATIONS INVOLVED ITS FORWARD AND REVERSE LOGISTICS ACTIVITIES. CURRENTLY, DELIVERY DATES ARE OFFERED BY SAZEHGOSTAR-SAIPA TO SUPPLIERS AND EACH SUPPLIER SEPARATELY SHOULD EXECUTE THEIR TRANSPOTATIONS (SENDING PARTS AND RETURNING REUSABLE EMPTY PALLETS REQUIRED FOR PACKAGING OF PARTS) BY THEIR VEHICLES. BY USING THE VEHICLEROUTING PROBLEM (VRP) APPROACH, WE INTEGRATE THE GATHERING PARTS AND SUBASSEMBLIES FROM SUPPLIERS AND CARRY THEM TO THE PLANT OF SAIPA, MEANWHILE DELIVER THE EMPTY PALLETS TO THEM IN ORDER TO MINIMIZE THE TRANSPORTATION COSTS. DUE TO FINITE CAPACITY OF VEHICLES, WE CONSIDER CAPACITATED VRP (CVRP) AND OFFER A RAPID AND NEAR OPTIMUM SOLUTION USING TABU SEARCH META-HEURISTIC AND ANALYSIS THE SETTING OF ITS PARAMETERS.

LOCATION-ROUTING PROBLEM (LRP) IS ESTABLISHED AS A NEW RESEARCH AREA IN THE CONTEXT OF LOCATION ANALYSIS THAT CONCERNS SIMULTANEOUSLY BOTH THE PROBLEMS OF LOCATION OF FACILITIES AND ROUTING OF VEHICLES AMONG THE ESTABLISHED FACILITIES AND THE EXISTING DEMAND POINTS. IN THIS PAPER, THE LOCATION-ROUTING PROBLEM WITH FUZZY DEMANDS (LRPFD) IS CONSIDERED WHICH MAY ARISE IN MANY REAL LIFE SITUATIONS IN LOGISTICS MANAGEMENT AND A FUZZY CHANCE CONSTRAINED PROGRAM IS DESIGNED TO MODEL IT BASED ON FUZZY POSSIBILITY THEORY. A TABU SEARCH (TS) HEURISTIC IS PROPOSED TO SOLVE THE PROBLEM. THE EFFICIENCY OF THE SOLUTION PROCEDURE IS DEMONSTRATED USING A STANDARD BENCHMARK SET OF TEST PROBLEMS.

THE ISSUE OF REVERSE LOGISTICS OF BROKEN-DOWN CARS HAS BEEN REGARDED IN IRAN FOR MANY YEARS BOTH ECONOMICALLY, AND ENVIRONMENTALLY. THIS COUNTRY HAS MADE GREAT IMPROVEMENTS IN RECYCLING A LARGE NUMBER OF AUTOMOBILE PARTS, HOWEVER, AS IT IS REPORTED, NO SCIENTIFIC AND BASIC MEASURES ARE TAKEN TO RECYCLE THE ELECTRIC AND ELECTRONIC PARTS DESPITE THEIR DANGEROUS COMPONENTS IN THIS REGION. IT IS A WHILE, THAT THE ENVIRONMENTAL EXPERTS WARN TO THE GOVERNORS ABOUT THE END OF WASTED ELECTRIC AND ELECTRONIC PARTS.THE MAIN GOAL OF THIS PROJECT IS TO SURVEY THE REVERSE LOGISTICS OF ELECTRIC AND ELECTRONIC PARTS OF PRIDE AUTOMOBILE IN WASTE OR BROKEN-DOWN STATE WITH THE AIM OF MINIMIZING THE REVERSE LOGISTICS COSTS (SUCH AS TRANSPORTATION, …). AFTER DESIGNING AN ARITHMETIC MODEL TO DEFINE RECYCLE CENTERS FOR PARTS OF LEAD-ACID BATTERY AS THE MOST IMPORTANT ELECTRIC AND ELECTRONIC PART CHOSEN BY THE EXPERT GROUP IN PRIDE AUTOMOBILE, SCHOLARS DESCRIBE THE REVERSE LOGISTICS PROCESS FOR THIS PART BY DESIGNING ANOTHER MODEL AND CONCERNING SOME RESTRICTIONS BY USING LINGO SOFTWARE IN THIS PAPER.

HUB NETWORKS ARE TRANSPORTATION AND TELECOMMUNICATION SYSTEMS SO THAT SEVERAL ORIGIN/DESTINATION POINTS SEND AND RECEIVE PRODUCTS. HUB FACILITIES ARE USED TO CONSOLIDATE FLOWS FROM SEVERAL ORIGIN AND ROUTE TO THEIR DESTINATIONS, THIS LEADS TO A BETTER UTILIZATION OF TRANSPORTERS. THIS PAPER CONSIDERS A SINGLE ALLOCATION HUB MEDIAN PROBLEM, IN WHICH THE NUMBER OF HUBS IS NOT FIXED AND THE FIXED COST OF OPENING HUB NODES ARE CORPORATED. WE FORMULATE THIS PROBLEM REGARDING THE TIME EFFECT IN DESIGNING TRANSPORTATION NETWORKS. A GENETIC ALGORITHM IS PROPOSED TO SOLVE SUCH A HARD PROBLEM.THE ASSOCIATED COMPUTATIONAL RESULTS ARE PRESENTED ON THE INSTANCES OF THE CAB DATA SET. FINALLY, THE CONCLUSION IS GIVEN.

PROCUREMENT PLANNING AND PRODUCTION PLANNING ARE CHALLENGING PROBLEMS IN MANUFACTURING COMPANIES PARTICULARY IN MAKE-TO-ORDER (MTO) COMPANIES WHERE PRODUCTION IS TRIGGERED WHEN THE DEMAND IS RECEIVED FROM THE CUSTOMER. IN DETAIL, SELECTING THE BEST SUPPLIERS BETWEEN POTENTIAL SUPPLIERS AND FINDING SEQUENCE OF PRODUCTS WITH OPTIMAL COST AND THE LEAST DELIVERY TIME ARE SOME OF DECISIONS THAT MUST BE MADE. FOR THIS PURPOSE, A NEW MIXED-INTEGER NON LINEAR PROGRAMMING (MINLP) MODEL OF THE DESCRIBED PROBLEM IS PRESENTED. SINCE SUCH PROBLEMS CATEGORIZED INNP HARD CLASS, A VIBRATION-DAMPING OPTIMIZATION (VDO) ALGORITHM AS A NOVEL AND FAST METAHEURISTIC METHOD WITH USEFUL NEIGHBORHOOD SEARCH MECHANISM APPLIED. PARAMETERS OF ALGORITHMS ARE CALIBRATED BY MEANS OF TAGUCHI DESIGN OF EXPERIMENT. OBTAINED RESULTS COMPARED TO LINGO 8.0 SOFTWARE IN DIFFERENT SIZE OF TEST PROBLEMS. NUMERICAL RESULT ILLUSTRATES THE GREAT EFFICIENCY OF ALGORITHM AGAINST EXACT SOLVER, IN TWO QUALITY CRITERIONS, SOLUTION QUALITY AND COMPUTATION RUN TIME.ALSO, RESULTS SHOW A HIGH QUALITY PERFORMANCE IN ROBUSTNESS OF ALGORITHM.

CONSUMER RETURN POLICY IS COMMON IN RECENT YEARS. THE PRESENCE OF PRODUCT RETURN ADDS ONE DIMENSION TO THE RELATIONSHIP BETWEEN MANUFACTURERS AND RETAILERS AND UNDERSCORES THE IMPORTANCE OF COORDINATION. CONSIGNMENT CONTRACTS HAVE BEEN WIDELY EMPLOYED IN MANY INDUSTRIES. UNDER SUCH CONTRACT THE RETAILER RETURNS THE UNSOLD AND RETURNED PRODUCTS TO THE SUPPLIER. THIS PAPER INVESTIGATES HOW COMPETITION AMONG RETAILERS INFLUENCES THE SUPPLY CHAIN DECISIONS AND PROFITS UNDER THIS CONTRACT AND CONSUMER RETURN POLICY. WE FIND THAT THE RETAILERS BENEFIT MORE FROM THE CONSIGNMENT CONTRACT THAN FROM A PRICE ONLY CONTRACT.

IN SCM, SUPPLIER SELECTION HAS A CRUCIAL IMPORTANCE IN SUPPLY CHAIN. RECENT YEARS, HIGHLY ATTENTION HAS BEEN CONCENTRATED ON THIS SUBJECT. IN THIS PAPER, A MULTI-OBJECTIVE MODEL IS DEVELOPED BASED ON DECISION ON QUALITY SERVICE LEVEL AND COST OF PURCHASED GOODS. THE DIFFERENCE OF THIS RESEARCH IS CONSIDERING DISCOUNT INTO MODEL. IN THIS RESEARCH, FIRSTLY, SINGLE-OBJECTIVE AND SECONDLY MULTI-OBJECTIVE APPROACH IS EMPLOYED TO SOLVE THE MODEL.AN INCREMENTAL DISCOUNT IS ADDED TO MODEL TO FIND OUT THE OPTIMUM SUPPLIER SELECTION.ACCORDING TO METRIC SOLUTION, RESULTS CAN PREDICT OPTIMUM SELECTION OF SUPPLIERS AS WELL AS THE PURCHASED GOODS AMOUNT.

DURING THE TWO LAST DECADES, A WIDE RANG OF APPLICATION OF HUB NETWORK DESIGN PROBLEMS HAVE RECEIVED INCREASING ATTENTION IN THE FIELDS OF TRANSPORTATION, TELECOMMUNICATIONS, COMPUTER NETWORKS, POSTAL DELIVERY, LESS-THAN-TRUCK LOADING AND SUPPLY CHAIN MANAGEMENT. HUBS ARE SPECIAL FACILITIES USED FOR SWITCHING, TRANSSHIPMENT AND SORTING POINTS IN DISTRIBUTION SYSTEMS. HUB FACILITIES ARE USED TO CONSENTRATE FLOWS IN ORDER TO TAKE ADVANTAGE OF ECONOMIES OF SCALE. IN THIS RESEARCH A MULTIPLE ALLOCATION HUB LOCATION PROBLEM IS CONSIDERED AND IT IS ASSUMED EACH POTENTIAL HUB COULD HAVE MULTIPLE CAPACITY LEVELS. ALSO, A FIXED COST AND A MINIMUM CAPACITY FOR ALL LINKAGES ARE CONSIDERED. IN OTHERE WORDS, THE FLOW BETWEEN EACH LINKAGES CANNOT EXCEED FROM A PREDETERMINED CAPACITY. AT THE END, GAMS SOFTWARE WITH CPLEX SOLVER IS USED TO OPTIMIZE THE PROBLEM IN SMALL SIZES AND ALSO, TO CHECK THE FEASIBILITY OF THE NEW MODEL.

THIS PAPER EXAMINED ORGANIZATIONAL FACTORS THAT INFLUENCE ADOPTION OF RADIO FREQUENCY IDENTIFICATION TECHNOLOGY IN IRAN GAS COMPANY CENTRAL WAREHOUSES. RFID HAS THE DISTINCT ADVANTAGE OF COLLECTING DATA AT SOME DISTANCE FROM THE ACTUAL PRODUCT, WITH NO DIRECT LINE OF SIGHT.SUCH A DATA AUTOMATION SYSTEM FOR REAL-TIME TRACKING, SAFETY MONITORING AND OVERALL WAREHOUSE OPERATION LEADS TO REAL-TIME VISIBILITY AND TRACKING OF ASSETS AND INVENTORY THAT IS NECESSARY FOR A WAREHOUSE. IN THIS PAPER WE EXAMINED ORGANIZATIONAL FACTORS (STRUCTURAL: SIZE AND RESOURCES AND CENTRALIZATION AND CULTURAL: INNOVATIVENESS) ASSOCIATED WITH THE ADOPTION OF RFID IN GAS COMPANY WAREHOUSES. USING A SURVEY QUESTIONNAIRE, DATA WAS COLLECTED FROM ALL 30 GAS COMPANY CENTRAL WAREHOUSES EMPLOYEES. WE FOUND THAT ORGANIZATIONAL SIZE DO NOT SHOW ANY RELATIONSHIP WITH RFID ADOPTION AND CENTRALIZATION FINANTIONAL RECOURSES AND INNOVATIVENESS ARE POSITIVELY AND SIGNIFICANTLY ASSOCIATED WITH THE ADOPTION OF RFID. THE IMPLICATIONS OF THESE AND OTHER FINDINGS ARE DISCUSSED.

THE CONSIDERATION OF ITEMS WITH IMPERFECT QUALITY IN AN ECONOMIC ORDER QUANTITY (EOQ) MODEL HAS APPEALED TO MANY RESEARCHERS RECENTLY. NONETHELESS, ONLY A FEW PAPERS THERE ARE THAT CONSIDER THIS ASSUMPTION IN A SUPPLY CHAIN ALL OF WHICH ARE CENTRALIZED ONES. THE CENTRALIZED SUPPLY CHAINS ARE NOT REALISTIC IN MOST OF THE REAL-LIFE SITUATIONS AND IN THIS PAPER A TWO-ECHELON DECENTRALIZED SUPPLY CHAIN CONSISTING OF A MANUFACTURER WHO SELLS THE ITEMS TO A SUPPLIER WITH CONSIDERING ITEMS WITH IMPERFECT QUALITY IN A JUST IN TIME (JIT) ENVIRONMENT IS PROPOSED. STACKELBERG EQUILIBRIUM IS APPLIED TO THE MODEL WITH THE ASSUMING THE SUPPLIER AS THE LEADER AND THE MANUFACTURER AS THE FOLLOWER AND RESULTS OF THE CENTRALIZED AND THE CENTRALIZED MODELS ARE COMPARED AND THE CONCLUSION ARE DRAWN ACCORDING TO AN ILLUSTRATION EXAMPLE.

RECENTLY, THE TRANSFER POINT LOCATION PROBLEM IN WHICH DEMAND POINTS HAVE UNIFORMLY DISTRIBUTED COORDINATES AND ARE WEIGHTED FOR THE CASE OF MINIMAX OBJECTIVE AND PLANAR TOPOLOGY HAS BEEN INTRODUCED. IN THE REAL SITUATIONS, DIFFERENT POINTS OF AN AREA CAN BE CONSIDERED WITH DIFFERENT POSSIBILITY OF OCCURRENCE. BY SUCH CONSIDERATION, THE MODEL WILL BE MORE APPLICABLE. IN THIS PAPER, WE PROPOSE A NEW TPLP WHERE DEMAND POINTS ARE WEIGHTED AND HAVE POSSIBILISTIC COORDINATES.THE PROPOSED MODEL IS FORMULATED IN FUZZY UNCONSTRAINT LINEAR PROGRAMMING WHICH LEADS TO CONSTRUCT THE GENERAL MODEL BASED ON EXPERTS’ VIEWPOINTS AND THE FUZZY DECISION IS MADE USING THE OPTIMIZATION TECHNIQUES. TO REACH THE OPTIMUM OR NEAR OPTIMUM VALUES FOR ALL DECISION VARIABLES A FUZZY LOGIC CONTROLLER IS DEVELOPED. FINALLY, THE APPLICATION OF THE PROPOSED MODEL IS DEMONSTRATED BY USING TWO NUMERICAL EXAMPLES.

THIS STUDY FOCUSES ON MACHINE SCHEDULING AND CUSTOMER DELIVERY COORDINATION. FLOW SHOP SCHEDULING IS DEVELOPED WITH CONSIDERATION OF DELIVERY VEHICLE ROUTING PROBLEM THAT SERVES MULTIPLE CUSTOMERS WITH DIFFERENT LOCATIONS BY MULTIPLE HOMOGENEOUS VEHICLES IN ORDER TO MINIMIZE THE MAXIMUM TOTAL JOBS DELIVERY TIME FOR THE CUSTOMERS. A MIXED BINARY INTEGER PROGRAMMING MODEL IS DEVELOPED TO OPTIMALLY SOLVE THIS PROBLEM. THIS RESEARCH IS PRACTICAL IN DIFFERENT INDUSTRIES SUCH AS DAIRY PRODUCTS INDUSTRY SO THIS IS STUDIED IN PEGAH DAIRY PRODUCT IN TEHRAN. DUE TO THE COMPLEXITY OF THE INTEGRATED PROBLEM, THE OPTIMAL SOLUTION IS ACHIEVED IN SMALLER SIZE OF PROBLEM SO A SMALL-SIZE EXAMPLE IS PROPOSED WHICH COMES FROM CASE STUDY TO SOLVE THE PROBLEM USING THE PROPOSED MODEL TO GET OPTIMAL SCHEDULE.