BU275 Chapter Notes - Chapter 5: Set Cover Problem, Capital Budgeting, Integer Programming
Document Summary
Total integer model: all the decision variables are required to have integer solution values; & integer. 0-1 integer model: all the decision variables have integer values of zero or one (binary); & integer. Mixed integer model: some of the decision variables (but not all) are required to have integer or binary solutions. Same as lp: unique optimal solution, alternate optimal solutions (can be finite), unbounded problem, infeasible problem. Rounding off non-integer solution values to integer values result in less-than optimal (suboptimal) results. Rounding non-integer solution values up to the nearest integer value can result in an infeasible solution. When all constraints are , rounding down non-integer solution values ensures feasible solution. However, a rounded-down integer solution can result in a less-than-optimal (suboptimal) solution. Solving ip models is harder than lp models: solution methods include: Lp relaxation model, complete enumeration, computer solution, branch and bound.