全球运营管理课件new gom3-supplement and exercise.ppt

GOM3 Exercise Return to King for Using More Machines Number of Machines Type of next machine Machine Times (min)Cycle Time (min) Total Hourly Output Efficiency (%) ABCD 4-4310210647.5 5C435251276.0 6 7 8 9 10 11 12 13 14 Return to King for Using More Machines Number of Machines Type of next machine Machine Times (min)Cycle Time (min) Total Hourly Output Efficiency (%) ABCD 4-4310210647.5 5C435251276.0 6C433.33241579.2 7A233.3323.331881.4 8C232.5232079.2 9B21.52.522.52484.4 10C21.52223095.0 11D21.52123086.0 12A1.331.52123079.2 13C1.331.51.6711.673687.5 14C1.331.51.4311.54090.5 lQuestion: lThe model J Wagon is to be assembled on a conveyor belt. Five hundred wagons are required per day. Production time per day is 420 minutes, and the assembly steps and times for the wagon are given in the following Exhibit. Assignment: find the balance that minimizes the number of workstations, subject to cycle time and precedence constraints. TASKTASK TIME IN SECONDS DESCRIPTIONTASKS THAT MUST PRECEDE A45Position rear axle support and hand fasten four screws to nuts. - B11Insert rear axleA C9Tighten rear axle support screws to nutsB D50Position front axle assembly and hand fasten with four screws to nuts - E15Tighten front axle assembly screwsD F12Position rear wheel #1 and fasten hubcap.C G12Position rear wheel #2 and fasten hubcap.C H12Position front wheel #1 and fasten hubcap.E I12Position front wheel #2 and fasten hubcap.E J8Position wagon handle shaft on front axle assembly and hand fasten bolt and nut F, G, H, I K9Tighten bolt and nutJ 195 1. Draw a Precedence Diagram. A BC F J DE H I G K 45 sec 50 sec 11 sec 15 sec 9 sec 12 sec 12 sec 12 sec 12 sec 8 sec 9 sec 2. Determine workstation cycle time. Here we have to convert to seconds because Our task time are in seconds 3. Determine the theoretical minimum number of workstations required (the Actual number may be greater. A BC F J DE H I G K 45 sec 50 sec 11 sec 15 sec 9 sec 12 sec 12 sec 12 sec 12 sec 8 sec 9 sec WS1 WS2 WS3: B,E,C,F WS4: G,H,I,J WS5 TASKNUMBER OF FOLLOING TASKS A6 B or D5 C or E4 F,G,H or I2 J1 K0 4. Select assignment rules a. assign tasks in order of the largest number of following tasks b. assign tasks in order of longest task time 5. Make task assignments to form Workstation 1, Workstation 2 6. Calculate efficiency: assume 5 first? 7. Evaluate the solution. An efficiency of 77 percent indicates an imbalance or idle time of 27 percent across the entire line. 8. Is a better balance possible? Yes, Try balancing the line with rule b. and break ties with rule a. (This will give yo0u a feasible four-station balance. lQuestion lA company is considering adding a new feature that will increase unit sales by 6 percent and product cost by 10 percent. Profit is expected to increase by 16 percent of the increased sales. Initially the product cost incurred by the company was 63 percent of the sales price. Should be the feature be added? lLet the sales be $100M. lSolution lDay 1 lProblem 1 lSales increase by 6% = $100M x 6% = $6M lBenefits: Profits increase by 16% of the increased sales = $6M x 16% = $0.96M lCost: Increase product cost by 10% = ($100M x 63%) x 10% = $6.3M lBecause costs exceed benefits, the new feature should not be added. lQuestion lAn automobile manufacturer is considering a change in an assembly line that should save money due to a reduction in labor and material cost. The change involves the installation of four new robots that will automatically install windshields. The cost of the four robots, including installation and initial programming, is $400,000. Current practice is to amortize the initial cost of robots over two years on a straight-line basis. The process engineer estimates that one full-time technician will be needed to monitor, maintain, and reprogram the robots on an ongoing basis. This person will cost approximately $60,000 per year. Currently, the company uses four full-time employees on this job and they each make about $52,000 per year. One of these employees is a material handler, and this person will still be needed with the new process. To complicate matters, the process engineer estimates that the robots will apply the windshield sealing material in a manner that will result in a savings of $0.25 per windshield installed. How many automobiles need to be produced over the next two years to make the new robots an attractive investment? Due to the relatively short horizon, do not consider the time value of money. lSolution: lCost of the current process over the next two years is just the cost of the four full-time employees. l$52,000/employees x 4 employees x 2 years = $416,000 lThe cost of the new process over the next two years, assuming the robot is completely costed over that time, is the following: l($52,000/material handler + $60,000/technician) x 2 + $400,000/robots - $0.25 x autos lEquating the two alternatives: l l$416,000 = $624,000 - $0.25 x autos lSolving for the break-even point: l-$208,000/-$0.25 = 832,000autos lThis indicates that to break even, 832,000 autos would need to be produced with the robots over the next two years. lISO 9000 series Quality system l9001: model for quality assurance in design, production, installation, and servicing l9002: model quality assurance in production and installation. l9003: model for quality assurance in final inspection test. Guidelines for Use l9000: quality management and quality assurance standardsguidelines for selection and use. lQuality management and quality elements-guidelines Quality System Design/ development Procurement Production Installation Servicing ISO9002 Design/ development Procurement Production Installation Servicing ISO9003 ISO 9001 lQuestion Management is trying to decide whether Part A, which is produced with a consistent 3 percent defective rate, should be inspected. If it is not inspected, the 3 percent defectives will go through a product assembly phase and have to be replaced later. If all Part As are inspected, one-third of the defectives will be found, thus raising the quality to 2 percent defectives