Example of the “Principle of Median Location”
“GORILLA” pasta plant:

|
"Gorilla Plant Location Problem" |
|
|
|
|
|
|
|
|
|
|
|
||
|
STATE |
POP1996 |
"rail miles" |
Fargo |
Sioux Falls |
Milwaukee |
Mpls |
Ames |
Omaha |
Chicago |
Kansas City |
StLouis |
|
|
|
North Dakota |
633534 |
Fargo |
0 |
160 |
720 |
160 |
320 |
320 |
640 |
480 |
640 |
|
|
|
South Dakota |
721374 |
Sioux Falls |
160 |
0 |
720 |
480 |
320 |
160 |
640 |
480 |
640 |
|
|
|
Wisconsin |
5144123 |
Milwaukee |
720 |
720 |
0 |
560 |
400 |
560 |
80 |
560 |
240 |
|
|
|
Minnesota |
4639933 |
Mpls |
160 |
480 |
560 |
0 |
160 |
320 |
480 |
320 |
480 |
|
|
|
Iowa |
2831890 |
Ames |
320 |
320 |
400 |
160 |
0 |
160 |
320 |
160 |
320 |
|
|
|
Nebraska |
1622272 |
Omaha |
320 |
160 |
480 |
320 |
160 |
0 |
480 |
320 |
480 |
|
|
|
Illinois |
11731783 |
Chicago |
640 |
640 |
80 |
480 |
320 |
480 |
0 |
480 |
160 |
|
|
|
Kansas |
2574771 |
Kansas City |
480 |
480 |
560 |
320 |
160 |
320 |
480 |
0 |
160 |
|
|
|
Missouri |
5322268 |
StLouis |
640 |
640 |
240 |
480 |
320 |
480 |
160 |
160 |
0 |
|
|
|
total pop: |
35221948 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
freight rates from P. Baumol 8/27/97: |
|
|
|
|
|
|
|
|
|
||
|
|
|
by rail |
by truck |
|
|
|
|
|
|
|
|
|
|
|
|
|
Wheat |
pasta |
ton wheat/ton pasta is: |
1.1 |
|
|
|
|
|
|
|
|
|
|
$/ton/mi |
$0.15 |
$0.38 |
tons pasta/person/year is: |
0.025 |
50 |
lbs per year/person |
|
|
|
|
||
|
|
|
pop: |
633534 |
721374 |
5144123 |
4639933 |
2831890 |
1622272 |
11731783 |
2574771 |
5322268 |
Annual |
compared
to |
|
|
|
Fargo |
Fargo |
Sioux Falls |
Milwaukee |
Mpls |
Ames |
Omaha |
Chicago |
Kansas City |
StLouis |
transport
costs |
AMES |
|
|
Fargo |
$0 |
$0 |
$1,096,488 |
$35,185,801 |
$7,052,698 |
$8,608,946 |
$4,931,707 |
$71,329,241 |
$11,740,956 |
$32,359,389 |
$172,305,226 |
127% |
|
|
Sioux Falls |
$23,246,486 |
$962,972 |
$0 |
$35,185,801 |
$21,158,094 |
$8,608,946 |
$2,465,853 |
$71,329,241 |
$11,740,956 |
$32,359,389 |
$207,057,738 |
153% |
|
|
Milwaukee |
$104,609,186 |
$4,333,373 |
$4,934,198 |
$0 |
$24,684,444 |
$10,761,182 |
$8,630,487 |
$8,916,155 |
$13,697,782 |
$12,134,771 |
$192,701,577 |
142% |
|
|
Mpls |
$23,246,486 |
$962,972 |
$3,289,465 |
$27,366,734 |
$0 |
$4,304,473 |
$4,931,707 |
$53,496,930 |
$7,827,304 |
$24,269,542 |
$149,695,613 |
111% |
|
|
Ames |
$46,492,971 |
$1,925,943 |
$2,192,977 |
$19,547,667 |
$7,052,698 |
$0 |
$2,465,853 |
$35,664,620 |
$3,913,652 |
$16,179,695 |
$135,436,078 |
100% |
|
|
Omaha |
$46,492,971 |
$1,925,943 |
$1,096,488 |
$23,457,201 |
$14,105,396 |
$4,304,473 |
$0 |
$53,496,930 |
$7,827,304 |
$24,269,542 |
$176,976,250 |
131% |
|
|
Chicago |
$92,985,943 |
$3,851,887 |
$4,385,954 |
$3,909,533 |
$21,158,094 |
$8,608,946 |
$7,397,560 |
$0 |
$11,740,956 |
$8,089,847 |
$162,128,720 |
120% |
|
|
Kansas City |
$69,739,457 |
$2,888,915 |
$3,289,465 |
$27,366,734 |
$14,105,396 |
$4,304,473 |
$4,931,707 |
$53,496,930 |
$0 |
$8,089,847 |
$188,212,926 |
139% |
|
|
StLouis |
$92,985,943 |
$3,851,887 |
$4,385,954 |
$11,728,600 |
$21,158,094 |
$8,608,946 |
$7,397,560 |
$17,832,310 |
$3,913,652 |
$0 |
$171,862,946 |
127% |
|
FACTS: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
The
Gorilla Pasta company wants to serve the Midwest market |
|
|
|
|
|
|
|
$142,595,356.00 |
|
||||
|
They
plan on selling 50/lbs pasta/person/year in that market. |
How many tons/person is that @ 2000 lbs/ton? |
|
|
|
|
|
|||||||
|
Pasta
production technology requires 1.1 ton wheat for each ton pasta produced |
|
|
|
|
|
|
|
|
|||||
|
The
minimum efficient scale of pasta production is reached at about 2,000 tons
per day |
How many tons per year is that @365 days/yr? |
|
|
|
|||||||||
|
An
unlimited supply of wheat can be obtained from Fargo, North Dakota. |
|
|
|
|
|
|
|
|
|||||
|
It
costs $0.15/ton/mile to ship wheat by rail. It costs $0.38/ton/mile to
ship pasta by truck. |
|
|
|
|
|
|
|
||||||
|
Distances
between rail stops in the Midwest, and actual data on the populations around
each stop, are listed above |
|
|
|
|
|
||||||||
|
QUESTIONS: |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
How
many plants should Gorilla open in the Midwest? |
|
|
|
|
|
|
|
|
|
||||
|
Where
should the plant(s) be located? The criterion is: |
|
|
|
|
|
|
|
|
|
||||
|
|
choose the site to minimize input transport costs |
input T costs = |
qi * ti * D(Fargo-site)*total mkt Q |
|
|
|
|||||||
|
|
plus output transport costs |
|
|
output T costs = |
SUM(POPm*
tons/person * to * Dsm) |
|
|
|
|||||
|
If
customers in Chicago are willing to pay twice as much per pound of pasta than
all the other Midwesterners, would the optimal plant location(s) be
different? |
|
|
|
||||||||||
|
What is the difference between the annual transport costs
at the SECOND best site and the best site, PER YEAR? |
|
|
|
|
|
|
|||||||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|