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If you have difficulty with Sensitivity Analysis, you may want to go over some of the slides of SA and watch a few minutes of the video for SA and video SA2 for details.
The conclusions are: 1) For the decision variables in the final solution, i.e., these decision variables have non zero values in the optimal solution: when one of the objective function coefficient (OFC) varies (yes, only one can change each time) within its lower and upper limits: a) the original optimal solution (OS) will REMAIN to be the optimal solution, b) the new objective function value (OFV) can be recomputed using the objective function where the changed objective function coefficient should be used. c) Do you know what is the value of the reduced cost for these basic decision variables with non zero values in the optimal solution?
2) For the decision variables not in the final solution, i..e., these decision variables have zero values in the optimal solution: when one of the objective function coefficient (OFC) varies (yes, only once can change each time) within its lower and upper limits, a) NO CHANGE to the original optimal solution (OS) and b) NO CHANGE to the original optimal objective function value (OFV). c) By the way, do you remember what is the reduced cost?
3) when one of the right hand side value (RHSV) for a binding constraint varies (yes, only one can change each time) within its lower and upper limits: a) the original optimal solution (OS) will CHANGE due to the change of the feasible region, the new OFV may not be available without using Excel@ Solver to compute it again, and b) the new objective function value (OFV) can be recomputed by using the corresponding shadow price of the constraint. c) By the way, do you remember what is shadow price?
4) when one of the right hand side value (RHSV) for a non binding constraint varies (yes, only one can change each time) within its lower and upper limits, then a) NO CHANGE to the original optimal solution (OS) and b) NO CHANGE to the original optimal objective function value (OFV). c) Do you know what is the value of shadow prices for non binding constraints?
Week 6, Sensitivity Analysis (Ch.4) and LP Modeling Introduction (Ch.3) Before next class:
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