Reconsider the Union Airways problem and its spreadsheet model that was dealt with in Prob. 7.3-6. Management now is considering increasing the level of service provided to customers by increasing one or more of the numbers in the rightmost column of Table 3.19 for the minimum number of agents needed in the various time periods. To guide them in making this decision, they would like to know what impact this change would have on total cost. Use Solver to generate the sensitivity report in preparation for addressing the following questions.
(a) Which of the numbers in the rightmost column of Table 3.19 can be increased without increasing total cost? In each case, indicate how much it can be increased (if it is the only one being changed) without increasing total cost.
(b) For each of the other numbers, how much would the total cost increase per increase of 1 in the number? For each answer, indicate how much the number can be increased (if it is the only one being changed) before the answer is no longer valid.
(c) Do your answers in part (b) definitely remain valid if all the numbers considered in part (b) are simultaneously increased by one?
(d) Do your answers in part (b) definitely remain valid if all 10 numbers are simultaneously increased by one?
(e) How far can all 10 numbers be simultaneously increased by the same amount before your answers in part (b) may no longer be valid?