**Example: Product
Planning –Graphical Solution**

Intersection of all feasible regions (of all inequalities including the non-negativity conditions) makes a convex polygon. A convex polygon exists when a line drawn between any two points in the polygon stays within the boundaries of that polygon. The convex polygon can be reduced to a line (if one of the constrain is equality) or to a point (if there are more equalities). If the convex polygon does not exist, the LP model does not have any feasible solution.