1 00:00:09,500 --> 00:00:11,960 To illustrate how linear optimization works in revenue 2 00:00:11,960 --> 00:00:14,290 management, let us consider a simple example -- 3 00:00:14,290 --> 00:00:17,620 a flight from New York to Los Angeles. 4 00:00:17,620 --> 00:00:20,980 In this flight, there are two types of economy fares, 5 00:00:20,980 --> 00:00:25,930 Early Bird fares that cost $238, and Last Minute fares 6 00:00:25,930 --> 00:00:29,170 that cost $617. 7 00:00:29,170 --> 00:00:32,320 In this flight, a Boeing 757 is used 8 00:00:32,320 --> 00:00:36,720 that has 166 economy seats. 9 00:00:36,720 --> 00:00:39,300 Demand for these prices has been forecasted 10 00:00:39,300 --> 00:00:42,390 using analytics tools, looking at historical data 11 00:00:42,390 --> 00:00:44,220 and incorporating models like time 12 00:00:44,220 --> 00:00:46,520 series or linear regression. 13 00:00:46,520 --> 00:00:49,920 Clearly, forecasts have errors, and therefore, we 14 00:00:49,920 --> 00:00:53,200 need to assess the sensitivity of our decisions 15 00:00:53,200 --> 00:00:54,980 to these errors. 16 00:00:54,980 --> 00:00:57,060 To illustrate the use of linear optimization, 17 00:00:57,060 --> 00:00:59,470 we assume that demand has already been forecasted. 18 00:01:02,220 --> 00:01:05,650 We'll illustrate how our decisions on how many discount 19 00:01:05,650 --> 00:01:11,860 seats to sell vary as the demand forecasts vary. 20 00:01:11,860 --> 00:01:14,340 If the demand for regular seats is 21 00:01:14,340 --> 00:01:19,500 50, and for discounted fares is 150, 22 00:01:19,500 --> 00:01:24,250 and the capacity is 166 seats, then the optimal allocation 23 00:01:24,250 --> 00:01:28,800 is going to be to sell the 50 seats to satisfy 24 00:01:28,800 --> 00:01:33,610 the regular demand, and then we allocate the remaining 116 25 00:01:33,610 --> 00:01:37,770 seats to the discounted fare class. 26 00:01:37,770 --> 00:01:40,700 If the regular demand increases to 100 seats, 27 00:01:40,700 --> 00:01:46,080 then we allocate these 100 seats to these customers, and only 28 00:01:46,080 --> 00:01:49,910 66 seats to discounted fare customers. 29 00:01:49,910 --> 00:01:53,710 Finally, if the regular demand increases to 200, 30 00:01:53,710 --> 00:01:58,130 then we allocate all of our capacity, 166 seats, 31 00:01:58,130 --> 00:02:00,260 to these customers. 32 00:02:00,260 --> 00:02:03,200 While this seems simple, what happens 33 00:02:03,200 --> 00:02:09,830 if we have 100 flights with connections in tens of fares? 34 00:02:09,830 --> 00:02:13,480 We'll next see how to formulate the problem mathematically 35 00:02:13,480 --> 00:02:17,920 and solve it in a systematic way, using linear optimization.