set 10 due today also c-5 due today thurs (may 16): deadline for late homework (today’s...
TRANSCRIPT
Set 10 due today
• Also c-5 due today
• Thurs (May 16): deadline for late homework (today’s assignments under door BB 4133 Friday before 3PM)
• Final exam Tues May 21 5:30-7:30
• 2 sheets of notes, Scantron
• Sets 1,9,10;C-1;short answer, mult choice
ANSWERS set 10
WAIT LINE
30,24
L=24 30-24
• (1)(a)L=4 people in drug store
(1)(b)Lq
• Lq = 24*24 30(30-24)
• Lq= 3.2
people waiting for service
(1)(c) W= 1 30-24
• W=.167 hr
• Interpret: W = 10 minutes from time you enter drug store until time you leave
(1)(d) Wq
• Wq = 24 30(30-24)
• Wq= .13 hour
• Interpret: 8 minutes before service
(1)(e) U=24/30=.80
• 80% efficiency
• P(server busy)
(1)(f) Po=1-.8=.2
• P(no waiting)
(2) Cost of Waiting
• Av 3 customers arrive per hour(given)
• 10 hours per day(given)
• You compute: 30 customers/day
• Cost of waiting $5 per hour(given)
WAIT COST
(A) (B)
#SERVED/HR 60/5=12 60/10=6
WAIT TIME 3 = .028
12(12-3)
3 = .167
6(6-3)
DAILY WAIT TIME
30(.028)=.83 30(.167)=5
WAIT COST .83(5)=$4.17 5(5)=$25
Labor Cost
(a) (b)
Hourly wage $16 $8
Labor Cost 10(16)=$160 10(8)=$ 80
Total Cost
(a) (b)
Wait 4.17 25
Labor 160 80
Total $164.17 $105=MIN
(3) SIMULATION
ARRIVAL PROB CUMUL ARR RN
0 .13 .13 01 to 13
1 .17 .30 14 to 30
2 .15 .45 31 to 45
3 .25 .70 46 to 70
4 .20 .90 71 to 90
5 .10 1 91 to 00
(3) MAXIMUM UNLOADED
MAX UNL PROB CUMUL RN UNL
1 .03 .03 01 TO 03
2 .12 .15 04 TO 15
3 .40 .55 16 TO 55
4 .28 .83 56 TO 83
5 .12 .95 84 TO 95
6 .05 1 96 TO 00
FIRST 5 DAYS: RN
ARR RN SIM ARR UNL RN SIM UNL
37 2 69 4
77 4 84 5
13 0 12 2
10 0 94 5
02 0 51 3
delay
• Case 1: Demand > Supply Delay = Demand – Supply
• Case 2: Demand < Supply Delay =0
• Next slide: Demand = 2B UNL Supply = UNL
FIRST 5 DAYS
DELAY ARRIV 2B UNL MAX U UNL
0 2 2 4 2
0 4 4 5 4
0 0 0 2 0
0 0 0 5 0
0 0 0 3 0
DAYS 6-10
DELAY ARRIV 2B UNL MAX U UNL
0 1 1 3 1
0 2 2 3 2
0 1 1 1 1
0 2 2 2 2
0 4 4 3 3
DAYS 11-15
DELAY ARRIV 2B UNL MAX U UNL
4-3=1 2 3 3 3
3-3=0 5 5 3 3
5-3=2 4 6 4 4
6-4=2 2 4 3 3
4-3=1 2 3 3 3
Av number delayed per day
Total delayed= 1+2+2+1= 6
Number of days = 15
Av = 6/15= 0.4