Case assignment

CASE ASSIGNMENT: EZ TRAILERS, INC
Alejandro Ayuso and Eduardo Sainz
In this problem we should analyze the case of Ez trailers incorporated, a company which produces a line for boat trailers. Their best trailers are EZ-190 and EZ-250. Of course there is an existing demand for both boats that should be satisfied. The company first cares about fulfilling the demand for EZ-250 and then about theothers. Its final goal is to limit fluctuations of hours to 1000 from one month to the next one.
In this problem we have some variables:
X1= Nº of units of EZ250 in March
X2=” “ in April
Y1= Nº of units of EZ190 in March
Y2= “ “ in April
It takes 4 hours to produce an EZ-190 and six hours to produce an EZ-250 and we know thatFebruary’s production time was 6300 and that it increases by 1000 hours from one month to the next one.
The firs objective is to satisfy existing order for EZ-250, that is minimize d minus, because the company does not want to produce less than people demands:
Min d1minus+d2minus
s.t.
X1-d1plus+d1minus=1100
X2-d2plus+d2minus=1200
Y1-d3plus+d3minus=800
Y2-d4plus+d4minus=6006X1+4Y1-d5plus+d5minus=7300
6X2+4Y2-d6plus+d6minus=8300
The solution is the following:
OBJECTIVE FUNCTION VALUE

1) 0.0000000E+00

VARIABLE VALUE REDUCED COST
D1MINUS 0.000000 1.000000
X1 1216.666626 0.000000
D1PLUS 116.666664 0.000000
X2 1383.333374 0.000000
D2PLUS 183.3333280.000000
D2MINUS 0.000000 0.000000
Y1 0.000000 0.000000
D3PLUS 0.000000 0.000000
D3MINUS 800.000000 0.000000
Y2 0.000000 0.000000
D4PLUS 0.000000 0.000000
D4MINUS 600.000000 0.000000
D5PLUS 0.000000 0.000000
D5MINUS0.000000 0.000000
D6PLUS 0.000000 0.000000
D6MINUS 0.000000 0.000000


ROW SLACK OR SURPLUS DUAL PRICES
2) 0.000000 0.000000
3) 0.000000 0.000000
4) 0.000000 0.000000
5) 0.000000 0.000000
6) 0.0000000.000000
7) 0.000000 0.000000

Once we make sure that we will produce at least the quantity demanded of EZ-250( d1 minus and d2 minus are equal 0, so demand will be satisfied in March and April we should do the same with EZ-190.
GOAL 2: minimize d3 minus and d4 minus.
Min d3minus
s.t.
X1-d1plus+d1minus=1100
X2-d2plus+d2minus=1200
Y1-d3plus+d3minus=800Y2-d4plus+d4minus=600
6X1+4Y1-d5plus+d5minus=7300
6X2+4Y2-d6plus+d6minus=8300
d1minus=0
d2minus=0
Solution:

1) 0.0000000E+00

VARIABLE VALUE REDUCED COST
D3MINUS 0.000000 1.000000
X1 1100.000000 0.000000
D1PLUS 0.000000 0.000000
D1MINUS 0.000000 0.000000
X21383.333374 0.000000
D2PLUS 183.333328 0.000000
D2MINUS 0.000000 0.000000
Y1 800.000000 0.000000
D3PLUS 0.000000 0.000000
Y2 0.000000 0.000000
D4PLUS 0.000000 0.000000
D4MINUS 600.000000 0.000000
D5PLUS 2500.000000 0.000000D5MINUS 0.000000 0.000000
D6PLUS 0.000000 0.000000
D6MINUS 0.000000 0.000000


ROW SLACK OR SURPLUS DUAL PRICES
2) 0.000000 0.000000
3) 0.000000 0.000000
4) 0.000000 0.000000
5) 0.000000 0.000000
6)...