1 00:00:09,490 --> 00:00:12,020 In this recitation, we'll discuss operating room 2 00:00:12,020 --> 00:00:13,420 scheduling. 3 00:00:13,420 --> 00:00:17,510 That is, how hospitals can be made to run smoothly. 4 00:00:17,510 --> 00:00:21,030 In particular, we'll discuss how an operating room manager can 5 00:00:21,030 --> 00:00:23,850 use integer optimization to make sure the hospital runs 6 00:00:23,850 --> 00:00:25,790 smoothly. 7 00:00:25,790 --> 00:00:28,730 So hospitals have a limited number of operating rooms, 8 00:00:28,730 --> 00:00:30,290 or ORs. 9 00:00:30,290 --> 00:00:33,330 And operating room managers must determine a weekly schedule 10 00:00:33,330 --> 00:00:37,040 assigning ORs to different departments in the hospital. 11 00:00:37,040 --> 00:00:38,540 If you look on the right, you'll see 12 00:00:38,540 --> 00:00:40,870 a picture of an operating room. 13 00:00:40,870 --> 00:00:44,360 You can see immediately how much specialized and fancy equipment 14 00:00:44,360 --> 00:00:45,590 there is. 15 00:00:45,590 --> 00:00:49,080 And you have to remember that for any surgery, staffing 16 00:00:49,080 --> 00:00:51,790 the OR doesn't just involve the surgeon performing 17 00:00:51,790 --> 00:00:56,270 the surgery, but also other doctors, nurses, residents, 18 00:00:56,270 --> 00:00:56,980 and fellows. 19 00:00:56,980 --> 00:01:00,490 There's usually an entire surgery team. 20 00:01:00,490 --> 00:01:03,540 So due to the specialized equipment in an OR, 21 00:01:03,540 --> 00:01:06,200 as well as the specialized staff members, 22 00:01:06,200 --> 00:01:08,910 it's been estimated that staffing an operating room 23 00:01:08,910 --> 00:01:12,140 costs over $100 a minute. 24 00:01:12,140 --> 00:01:14,600 Therefore, for a hospital to run on a budget, 25 00:01:14,600 --> 00:01:17,050 it's very critical for the operating room manager 26 00:01:17,050 --> 00:01:20,340 to create a good schedule. 27 00:01:20,340 --> 00:01:22,820 However, this isn't without difficulties. 28 00:01:22,820 --> 00:01:25,860 Creating an acceptable schedule is a highly political process 29 00:01:25,860 --> 00:01:27,890 within the hospital. 30 00:01:27,890 --> 00:01:31,220 Surgeons are frequently paid on a fee-for-service basis, which 31 00:01:31,220 --> 00:01:34,380 means they get paid for every surgery they perform. 32 00:01:34,380 --> 00:01:36,450 That means that when you change their allocated 33 00:01:36,450 --> 00:01:39,210 number of operating room hours, it directly 34 00:01:39,210 --> 00:01:41,300 affects their income. 35 00:01:41,300 --> 00:01:44,240 Therefore, the operating room managers' proposed schedule 36 00:01:44,240 --> 00:01:46,740 must strike a delicate balance between all 37 00:01:46,740 --> 00:01:49,770 the surgical departments in the hospital. 38 00:01:49,770 --> 00:01:51,740 However, there are many logistical issues 39 00:01:51,740 --> 00:01:53,690 for the operating room manager to consider 40 00:01:53,690 --> 00:01:56,350 when designing the schedule. 41 00:01:56,350 --> 00:02:00,140 Operating rooms are staffed in eight hour blocks. 42 00:02:00,140 --> 00:02:02,380 Each department sets their own target number 43 00:02:02,380 --> 00:02:06,810 of allocation hours, which may not be integer. 44 00:02:06,810 --> 00:02:08,340 In addition, departments may have 45 00:02:08,340 --> 00:02:10,630 daily and weekly requirements. 46 00:02:10,630 --> 00:02:15,270 For example, gynecology might need at least one OR per day. 47 00:02:17,970 --> 00:02:23,470 Ophthalmology might need at least two ORs per week. 48 00:02:23,470 --> 00:02:25,230 And for example, the oral surgeon 49 00:02:25,230 --> 00:02:30,180 might only be present on Tuesdays and Thursdays. 50 00:02:30,180 --> 00:02:32,870 The operating room manager needs to take into account 51 00:02:32,870 --> 00:02:34,550 all of these logistical issues when 52 00:02:34,550 --> 00:02:35,870 designing a feasible schedule. 53 00:02:38,990 --> 00:02:41,750 In this recitation, we'll consider a case study 54 00:02:41,750 --> 00:02:45,570 of Mount Sinai Hospital in Toronto. 55 00:02:45,570 --> 00:02:49,140 There are 10 operating rooms at Mount Sinai, which 56 00:02:49,140 --> 00:02:52,160 are staffed from Monday through Friday. 57 00:02:52,160 --> 00:02:56,920 So 10 ORs times 5 days times 8 hours per day, 58 00:02:56,920 --> 00:03:00,630 means that they have 400 hours to assign between five 59 00:03:00,630 --> 00:03:03,350 different surgical departments. 60 00:03:03,350 --> 00:03:05,160 The departments they are assigning 61 00:03:05,160 --> 00:03:11,860 are ophthalmology, gynecology, oral surgery, otolaryngology, 62 00:03:11,860 --> 00:03:14,300 and general surgery. 63 00:03:14,300 --> 00:03:16,100 Each of these departments has come up 64 00:03:16,100 --> 00:03:19,740 with a weekly number of target allocation hours. 65 00:03:19,740 --> 00:03:23,600 For example, ophthalmology requests 39.4 hours 66 00:03:23,600 --> 00:03:28,180 of operating room time, and otolaryngology requests 67 00:03:28,180 --> 00:03:33,850 26.3 hours of operating room time. 68 00:03:33,850 --> 00:03:37,690 Now, it's very clear that just by looking at these numbers 69 00:03:37,690 --> 00:03:39,950 they are not integer, and they are certainly not 70 00:03:39,950 --> 00:03:42,400 multiples of eight hours. 71 00:03:42,400 --> 00:03:46,090 This means that it's impossible for the operating room manager 72 00:03:46,090 --> 00:03:50,160 to give any department exactly their weekly number of target 73 00:03:50,160 --> 00:03:52,230 allocation hours. 74 00:03:52,230 --> 00:03:54,340 However, the operating room manager 75 00:03:54,340 --> 00:03:58,900 would like to try to give as many hours to each department 76 00:03:58,900 --> 00:04:03,280 as possible up to their target allocation number. 77 00:04:03,280 --> 00:04:07,800 We'll see how to solve this with integer optimization. 78 00:04:07,800 --> 00:04:10,130 Let's consider the rest of the problem data. 79 00:04:10,130 --> 00:04:13,360 For example, we need to consider the number of surgery teams 80 00:04:13,360 --> 00:04:16,360 from each department that is available each day. 81 00:04:16,360 --> 00:04:18,940 We also need to consider the maximum number of operating 82 00:04:18,940 --> 00:04:22,210 rooms required by each department each day. 83 00:04:22,210 --> 00:04:24,740 Frequently, these numbers are the same. 84 00:04:24,740 --> 00:04:30,020 For example, ophthalmology requires at most two operating 85 00:04:30,020 --> 00:04:33,170 rooms every day. 86 00:04:33,170 --> 00:04:35,030 And we see that they have two surgery 87 00:04:35,030 --> 00:04:38,630 teams available every day. 88 00:04:38,630 --> 00:04:42,100 However, let's look at the case of oral surgery. 89 00:04:42,100 --> 00:04:45,860 They require at most one operating room every day. 90 00:04:45,860 --> 00:04:47,830 However, the oral surgeon is only 91 00:04:47,830 --> 00:04:50,250 present on Tuesdays and Thursdays. 92 00:04:54,640 --> 00:04:57,450 Additionally, each department has weekly requirements 93 00:04:57,450 --> 00:05:00,160 on the number of operating rooms they need. 94 00:05:00,160 --> 00:05:04,690 For example, gynecology needs to have at least 12 operating 95 00:05:04,690 --> 00:05:07,470 rooms in a given week and at most 18. 96 00:05:13,540 --> 00:05:15,320 The traditional way of doing this 97 00:05:15,320 --> 00:05:18,580 was not by using integer optimization. 98 00:05:18,580 --> 00:05:20,680 Before integer optimization was implemented 99 00:05:20,680 --> 00:05:24,470 at Mount Sinai in 1999, the operating room manager 100 00:05:24,470 --> 00:05:26,740 used graph paper and a large eraser 101 00:05:26,740 --> 00:05:29,930 to try to assign the operating room blocks. 102 00:05:29,930 --> 00:05:31,770 Any changes that were necessary were 103 00:05:31,770 --> 00:05:35,050 incorporated by trial and error. 104 00:05:35,050 --> 00:05:37,170 The operating room manager made a draft, 105 00:05:37,170 --> 00:05:41,310 and this schedule was circulated to all of the surgical groups. 106 00:05:41,310 --> 00:05:44,409 However, incorporating feedback from one department 107 00:05:44,409 --> 00:05:47,230 usually meant altering another group's schedule leading 108 00:05:47,230 --> 00:05:48,820 to many iterations of this process. 109 00:05:53,600 --> 00:05:57,400 In the next video, we'll design an integer optimization 110 00:05:57,400 --> 00:05:59,950 formulation for this problem.