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Descision Modeling
Chap 4-5
42
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Not Applicable
08/23/2005

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Term
Shadow Price
Definition
The measure that shows the change in the optimal objective function value for a unit increase in a constraint RHS value is the
Term
Reduced cost
Definition
The measure that compares the marginal contribution of a variable with the marginal worth of the resources it consumes is the
Term
True
Definition
For a non-binding constraint the shadow price will always equal zero (T/F)
Term
Reduced cost
Definition
The measure the shows the change in the optimal objective function value if a product that is not currently being produced is forced to be produced
Term
The allowable increase in the RHS value of the constraint for which the current optimal corner point remains optimal
Definition
For a constraint the allowable increase column in the sensitivity report shows
Term
True
Definition
When analyzing simultaneous changes in parameter values, we need to first verify the 100% rule (T/F)
Term
False
Definition
If the 100% rule is violated the information in the sensitivity report is always invalid (T/F)
Term
Decrease
Definition
If the RHS value of a ≥ constraint increases, the optimal value of a maximize objective function can never
Term
The problem needs to be solved again to get a new sensitivity report
Definition
If we wish to increase a constraint RHS value beyond the allowable increase value shown in the sensitivity report, this means
Term
Analyze the impact of the introduction of a new variable
Definition
The pricing our procedure allows us to
Term
True
Definition
Sensitivity reports can be used to detect the presence of alternate optimal solutions (T/F)
Term
False
Definition
The reduced cost of a variable that has the value of zero in the current optimal solution will always be nonzero (T/F)
Term
Increase
Definition
If the RHS value of a ≤ constraint decreases, the optimal value of a maximize objective function can never
Term
Surplus
Definition
Difference between the LHS and RHS values of a ≥ constraint
Term
The current variable values remain the same, but the objective value would change
Definition
If the objective function coefficient of a variable changes within its allowable range
Term
Allowable Decrease for an OFC.
Definition
The maximum amount by which the OFC of a decision variable can decrease for the cur-rent optimal solution to remain optimal.
Term
Allowable Decrease for a RHS Value.
Definition
The maximum amount by which the RHS value of a constraint can decrease for the shadow price to be valid.
Term
Allowable Increase for an OFC.
Definition
The maximum amount by which the OFC of a decision variable can increase for the cur-rent optimal solution to remain optimal.
Term
Allowable Increase for a RHS Value.
Definition
The maximum amount by which the RHS value of a constraint can increase for the shadow price to be valid.
Term
Answer Report.
Definition
A report created by Solver when it solves an LP model. This report presents the optimal solution in a detailed manner.
Term
Objective Function Coefficient (OFC).
Definition
The coefficient for a decision variable in the objective function. Typically, this refers to unit profit or unit cost.
Term
100% Rule.
Definition
A rule used to verify the validity of the information in the sensitivity report when dealing with simultaneous changes to more than one RHS value or more than one OFC value.
Term
Pricing Out.
Definition
A procedure by which the shadow price information in the sensitivity report can be used to gauge the impact of the addition of a new variable in the LP model.
Term
Reduced Cost.
Definition
Difference between the marginal contribution to the objective function value from the inclusion of a decision variable and the marginal worth of the resources it consumes. In the case of a decision variable that has an optimal value of zero, it is also the minimum amount by which the OFC of that variable should change before it would have a nonzero optimal value.
Term
Right-Hand Side (RHS) Value.
Definition
The amount of resource available (for a <= constraint) or the minimum requirement of some criterion (for a >=constraint). Typically expressed as a constant for sensitivity analysis.
Term
Sensitivity Analysis.
Definition
The study of how sensitive an optimal solution is to model assumptions and to data changes. Also referred to as post-optimality analysis.
Term
Shadow Price.
Definition
The magnitude of the change in the objective function value for a unit increase in the RHS of a constraint.
Term
Slack.
Definition
Difference between the RHS and left-hand-side (LHS) of
A <= constraint. Typically represents the unused resource.
Term
Surplus.
Definition
Difference between the LHS and RHS of a >=constraint. Typically represents the level of over-satisfaction of a requirement.
Term
Transhipment node
Definition
A point or node that has shipments arrive as well as leave is called a
Term
Total flow in - Total flow out
Definition
The net flow at each node is calculated as
Term
An important funtion of sensitivity analysis is to experiment with the values of the input parameters
Definition
4-1 Discuss the role of sensitivity analysis in LP. Under what circumstances is it needed, and under what conditions do you think it is not necessary?
Term
Sensitivity Analysis
Definition
We can examine how sensitive the optimal solution is to changes in profits, resources, or other input parameters
Term
Postoptimality analysis
Definition
Examining changes after the optimal solution has been reached
Term
True
Definition
Changes in OFC values do not affect the size of the feasible region
Term
True
Definition
Changes in the RHS values usually affect the size of the feasible region
Term
True
Definition
Changes in constraint coefficients affect the shape of the feasible region
Term
i.e. if you have an increase in your wood constraint, you can build more tables
Definition
4-3 Explain how a change in resource availability can affect the optimal solution of a problem.
Term
i.e. if you have more electricion hours available, it may become more desirable to build radios vs CD palyers
Definition
Explain how a change in an objective function coefficient can affect the optimal solution of a problem.
Term
Did we discuss this?
Definition
4-7 How can a firm benefit from using the pricing out procedure?
Term
Certianty, the numbers used int he objective funtion and constraints are known with certianty, and do not change during the period bieng studied.

Usually we are given capacity of goods at each source, and requirement for goods at each destination
Definition
5-1 Is the transportation model an example of decision making under certainty or decision making under uncertainty? Why?
Term
If total supply exceeds total demand, the supply constraints are written as inequalities <=
Definition
5-2 What is a balanced transportation problem? Describe the approach you would use to solve an unbalanced problem
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