Answer the following question using the picture as reference

10.2 In Example 10.2, suppose that the vehicles operate according to the following scheduling rules: (1) vehicles delivering raw work parts from station 1 to stations 2, 3, and 4 must return empty to station 5; and (2) vehicles picking up finished parts at stations 2, 3, and 4 for delivery to station 5 must travel empty from station 1. (a) Determine the empty travel distances associated with each delivery and develop a from-to chart in the format of Table 10.5. (b) The AGVs travel at a speed of 50 m/min and the traffic factor = 0.90. Assume reliability = 100%. From Example 10.2, the delivery distance Ld = 103.8 m. Determine the value of Le. (c) How many automated guided vehicles will be required to operate the system?

EXAMPLE 10.2 Determining Ld for a More-Complex AGVS Layout The layout for this example is shown in Figure 10.15, and the from-to chart is presented in Table 10.5. The AGVS includes load station 1 where raw parts enter the system for delivery to any of three production stations 2,3 , and 4 . Unload station 5 receives finished parts from the production stations. Load and unload times at stations 1 and 5 are each 0.5min. Production rates for each workstation are indicated by the delivery requirements in Table 10.5. A complicating factor is that some parts must be transshipped between stations 3 and 4 . Vehicles move in the direction indicated by the arrows in the figure. Determine the average delivery distance, Ld. Solution: Table 10.5 shows the number of deliveries and corresponding distances between the stations. The distance values are taken from the layout drawing in Figure 10.15. To determine the value of Ld a weighted average must be calculated based on the number of trips and corresponding distances shown in the from-to chart for the problem: Ld=9+5+6+9+2+3+89(50)+5(120)+6(205)+9(80)+2(85)+3(170)+8(85)=424.360=103.8m Figure 10.15 AGVS layout for production system of Example 10.2. Key: Proc = processing operation, Aut = automated, Unld = unload, Man = manual operation, dimensions in meters (m)