Production Planning Control Operations Scheduling Dr.Na genG Prof.Zhibin JIANG Department of Industrial Engineering Management Shanghai Jiao Tong University
Production Planning & Control Dr. Na GENG Prof. Zhibin JIANG Department of Industrial Engineering & Management Shanghai Jiao Tong University Operations Scheduling
Operations Scheduling Contents Introduction Job Shop Scheduling Terminology ·Sequencing Rules Sequencing Theory for a Single Machine Sequencing Theory for Multiple Machines Stochastic Scheduling:Static Analysis Assembly Line Balancing 。Summary 国上泽充鱼大皇
Operations Scheduling Contents • Introduction • Job Shop Scheduling Terminology • Sequencing Rules • Sequencing Theory for a Single Machine • Sequencing Theory for Multiple Machines • Stochastic Scheduling: Static Analysis • Assembly Line Balancing • Summary
Assembly Line Balancing Example 8.11 The Final assembly of Noname personal computers,a generic mail-order PC clone,requires a total of 12 tasks.The assembly is done at the Lubbock,Texas, plant using various components imported from the Far East.The network representation of this particular problem is given in the following figure. 3 8 6 10
Example 8.11 The Final assembly of Noname personal computers, a generic mail-order PC clone, requires a total of 12 tasks. The assembly is done at the Lubbock, Texas, plant using various components imported from the Far East. The network representation of this particular problem is given in the following figure. Assembly Line Balancing
Assembly Line Balancing Precondition The job times and precedence Task Immediate Time relationships for this problem are Predecessors 1 12 summarized in the table below. 2 i 6 3 2 6 Question 4 2 2 Suppose that the company iS 2 2 6 2 12 willing to hire enough workers to 7 3,4 7 produce one assembled machine 8 7 5 9 5 1 every 15 minutes. 10 9,6 4 T/C=4.67 11 8,10 6 12 11 7 Five-station OK? Sum 70
Task Immediate Predecessors Time 1 _ 12 21 6 32 6 42 2 52 2 6 2 12 7 3, 4 7 87 5 95 1 10 9, 6 4 11 8, 10 6 12 11 7 Sum 70 Precondition The job times and precedence relationships for this problem are summarized in the table below. Question Suppose that the company is willing to hire enough workers to produce one assembled machine every 15 minutes. T/C=4.67 Five-station OK? Assembly Line Balancing
Assembly Line Balancing The solution precedence requires determining the positional weight of each task.The positional weight of task i is defined as the time required to perform task i plus the times required to perform all tasks having task i as a predecessor. t3+t+ts+tu+t2=31 Task Positional Weight 1 7 目 2 3 3 4 27 5 6 29 7 25 8 18 9 18 The ranking 10 17 1,2,3,6,4,7,5,8,9,10,11,12 11 13 12 7
Task Positional Weight 1 70 2 58 3 31 4 27 5 20 6 29 7 25 8 18 9 18 10 17 11 13 12 7 The solution precedence requires determining the positional weight of each task. The positional weight of task i is defined as the time required to perform task i plus the times required to perform all tasks having task i as a predecessor. Assembly Line Balancing t3+t7+t8+t11+t12=31 The ranking 1, 2, 3, 6, 4, 7, 5, 8, 9, 10, 11, 12