9. 15
a. From Equation 9.10
2 2 '
y =L=m=1250 units
2b 2(400)
2 , 2 '
b. current m = éba = = 0.05 < 0.075
« vra 0.8 ° 0.2 ° 1000
Use EOQ expressed as a time supply, based on current a.
~sz I 2-50 - -
T = = =o.791
I 9 Dvr (1000)(0.8)(0.2) - years
16.7
There are a variety of ways to answer this question depending on the capacity of
the shop. Students should develop a relatively balanced shop, so that, for instance, it is not acceptable to produce each product in one week. However, if
they argue th
Chapter 11
11.1
a. Div I a; %1' vi
1 1000000 5 0.00005
2 20000 5 0.00025
3 1000 21.5 0.0215
4 300 5 0.01667
5% is smallest for item J. .1 m; =1
DIV:
mi: (1,. Dv #1: aj100000
-. DI: vi: A + I vai
m2= .4921733: 1
m; = 4.525:>m3=5
m4 = 3.98
7.4
IF *
a. EOQ =42 = w =395units.
vr $8 " 016/ yr
b. Safety factor (k):
Q 395
D(TBS) = 4000* 6/ 12
satises p2 (k) = 0.198 , that is k = 0.850.
= 0.198 < 1. Hence, the safety factor is the value of k that
Safety stock (SS):
SS = k 01:0.85 * 100
5.1
5 .2
Chapter 5
Answers to End-of-Chapter Problems
a. Lat A1 and EOQl be the old values of A and EOQ. Then,
{2141) r A 2A'D (12.80 1 1
BO = = _ = 0 =
Q vr Al vr 3.20 Q Q
Thus,
i) EOQ = 800 units,
ii) vEOQ = $0.4oxunit X 800 units = $32
7.4
=1: :1:
a. .1509 = 12) = W = 395 units.
vr $8 * 0.16! yr
b. Safety factor (k):
Q 395
D(TBS) = 4000*6!12
satises p2 (k) = 0.198 , that is k = 0.850.
= 0.198 < 1. Hence, the safety factor is the value of k that-
Safety stock (SS):
SS = k 0}, =
2A A 2 Dv
5.6 a. T = or = T
EOQ Dvr r ( EOQ) 2
Here,
i _ (7 days)2 (200 units/day) x 0.03 Slunit
r 2
= 14'}r $ - days.
b. At EOQ with no discount, the cost per day is
TRC(EOQ) =JZAD_Vr+Dv mm '
At bfeakpoint |
TRCCQap)=W+é£+Dv(1d) ...(2)
by I!
IE 251 Sth
Production and Inventory Control "
Exam #1 Fall 2008
1...(32 pts)
nun-
A A
Leta =.2,,6 = .1,a3 =175,h20 = 53
a) find a
A
b) find b1
c) find 24,,
d) find the 4-point moving average centered at period 4
[a a4 : (pan (8% + £3) + of X4. :(flg
9.1
9.2
9.3
a. D = 50 units/yr.
Chapter 9
Answers to End-of-Chapter Problems
v = $0.40/unit
Dv = $20/yr A
From Table 9.1 Dv = 20 => 12 months time supply
Q = D = 50 units
b. IQ = 3-D = 12.5 units >10
12
normal
TBS = 20 + 12 month time supply
8.2
All oustanding orders at a time t must arrive by time HI. and no order placed
after I can arrive by t+L. Therefore,_ the net stock at time t+L must be equal to
the inventory position at time rminus any demand x0 in t to r+L. Now the
inventory positio