final exam Flashcards
write down Xij set variables format. transportation. Units from one center to another
Xij = number of units sent from “i” to destribution center “J”
2 things to always remember on objective function for transportation
- put the costs of producing and the the costs of shipping for each variable. dont forget putting the cost!
- always put min or max Z
always say these 3 things for constraints in transportation
- Subject to:
- verbalize constraints
3, non negativity, binary or integer constraint
supply and demand. when one is bigger, another one is less and when they are equal to each other. Solver programming
When demand is greater : set supply constraints to =
when supply is greater: set demand constraints to =
when supply and demand are the same: demand and supply constraints set to =
LP relaxation BIP formulation
is when you relax the binary and integer constraints to obtain the relaxed (optimal) solution
a relax solution for BIP formulation will never be better solution than the actual binary or integer solution. true or false
false, relaxed solutions will be always optimal. making the the normal solution for BIP feasible
how to activate the variables for fixed costs on BIP problems
supply/capacity constraints 400 is example:
x1-400y1<= 0 or
x2<=400y2
xn<=400yn
mutually exclusive constraint where we cannot have both: x1 and x3
x1 + x3 <= 1
x1 and x3 muttually exclusive constraint where we need 1 but not more
x1 + x3 = 1
if project 4 is selected then project 2 must also be selected
x4<= x2
or
x2>=x4
project 1 must also be if 5 and vice versa.
x1=x5
if project 1 is selected, then projects 2 and 3 must also be selected
2X1<= x2 + x3
if project 1 is selected, then projects 2 or 3 must also be selected
X1<= x2 + x3
project 1 cannot be selected if both projects 2 and 3 are selected
x1 + x2 + x3 <=2
if projects 2 and 3 are selected, then project 1 must also be selected
x2 + x3 <= X1 + 1
optimistic approach for decision analysis
maximax approach. best of best
conservative approach for decision analysis
maximin approach. best of worst
minimize regret approach
minimax. minimizes regret
how to calculate regret table
best pay off of state of nature - pay off chosen
steps for minimax regret approach
calculate regrets for each cell. get maximum regret per row. choose the one with least regret
decision making approach called laplace
equally likely approach
decisi9on making approach called hurwicz
realism approach
equally likely approach
maximizes the average payoff per row
approach called realism hurwicz. Decision analysis
finds a compromise between the best and worst pay off
