1. Pertemuan II

2. News Vendor Problem ( Continuous Demand )
Asumsi : D merupakan variabel random kontinu
yang merepresentasikan jumlah Permintaan
Nilai q (jmlh pesanan) optimal, dinotasikan q*,
adalah nilai q yang memenuhi :

3. Contoh
Nita berjualan tas untuk membayar biaya
kuliahnya. Tas dibelinya seharga Rp 100.000 dan
dijual seharga Rp 250.000 per tas. Jumlah tas
yang dpt Nita jual berdistribusi normal dengan
mean 100 tas dan standar deviasi 30 tas. Berapa
jmlh tas yg seharusnya Nita pesan?

4. Penyelesaian :
Diketahui : harga beli = Rp 100.000
harga jual = Rp 250.000
mean = 100
std dev = 30
Kasus 1 : d<=q TC
beli q tas = 100.000q
jual d tas = -250.000d
TC = 100.000q-250.000d
C0 = 100.000

5. Kasus 2 : d>=q+1 TC
beli q tas = 100.000q
jual q tas = -250.000q
TC = -150.000q
Cu = 150.000 Cu/(C0+Cu)=3/5=0,6

6. Latihan 1
The American Bar Association (ABA) is holding its annual convention
in Las Vegas. Six months before the convention begins, the ABA must
decide how many rooms should be reserved in the convention hotel. At
this time the ABA can reserve room at a cost of $50 per room, but six
months before the convention the ABA does not know with certainty
how many people will attend the convention. The ABA believes,
however, that the number of rooms required is normally distributed
with a mean of 5000 rooms and standard deviation of 2000 rooms. If
the number of rooms required exceeds the number of rooms reserved
at the convention hotel, extra rooms will have to found at neighboring
hotels at a cost of $80 per room. It is inconvenient for convention
participants to stay at neighboring hotels. We measure this
inconvenience by assessing an additional cost of $10 for each room
obtained at a neighboring hotel. If a goal is to minimize the expected
cost to ABA and its members, how many rooms should the ABA
reserve at the convention hotel?

7. Latihan 2
The ticket price for a New York – Indianapolis flight is
$200. Each plane can hold up to 100 passengers. Usually
some of the passengers who have purchased tickets for a
flight fail to show up (no-show). To protect against no
shows, the airline will try to sell more than 100 tickets for
each flight. Federal law states that any ticketed customer
who unable to board the plane is entitled to compensation
(say,$ 100). Past data indicate that the number of no-
shows for each NY – Indianapolis flight is normally
distributed with a mean of 20 and a standard deviation of
5. In order to maximize expected revenues less
compensation costs, how many tickets should the airline
sell for each flight ? Assume that anybody who doesn’t use
a ticket receives a $ 200 refund.