Systems with randomness are inherently subject to delay. But how does that delay vary over the day? That is, if we think of a service setting with “peak” hours that in some sense resets every day, when are delays worst? Note that this would be relevant for, say, a restaurant that closes every evening or for a hospital emergency room that doesn’t officially close but typically does see a dramatic drop in volume in the overnight hours. Intuitively, one would expect that delays build over the day. Now Nate Silver at FiveThirtyEight has provided a graphical illustration of how delay builds for a stochastic system — specifically for US domestic flights (Fly Early, Arrive On-Time, Apr 19).
Posts Tagged ‘Queues’
Pity the Transportation Security Administration! They have a tricky capacity planning problem with their Pre✓™ program. Here is how the TSA describes Pre✓™:
TSA Pre✓™ allows low-risk travelers to experience expedited, more efficient security screening at participating U.S. airport checkpoints for domestic and international travel.
The perks of the program of the program include being able to leave your shoes on, not having to take out your laptop, and leaving your baggie of toothpaste buried in your carry-on. All of that gets you faster screening and — in theory — a faster moving line. The program started off being by invitation but has broadened to include those enrolled in the Custom and Boarder Patrol Global Entry program. Now anyone can apply. The trade off for travelers is that you have to pony up for a background check. For the TSA, it allows them to expend fewer resources on people it knows something about so more time can be spent on those it has no information on.
So what’s the problem? The issue is how the system has to be implemented at airports. Pre✓™ flyers go in a separate line and then through separate equipment and personnel. But, as the Wall Street Journal tells it, that is costly for the TSA and they cannot readily justify dedicating the current resource levels unless they can get more flyers signed up (Trouble Selling Fliers on the Fast Airport Security Line, Apr 16).
TSA wants lots more people enrolled in Precheck to make better use of its designated security lanes, which currently number 590 at 118 U.S. airports. Since December, TSA has encouraged travelers to apply to the program directly. The agency is opening enrollment centers across the country, letting people who are U.S. citizens or permanent legal residents to make an appointment or drop in and have fingerprints taken digitally. The $85 background-check fee buys five years of enrollment.
“It’s one of the last great bargains the U.S. government is offering,” TSA Administrator John Pistole joked at an enrollment-center opening last week at Dallas-Fort Worth International Airport.
TSA said more than 1.2 million people as of December were able to use Precheck, mostly because they had enrolled in Global Entry. Since TSA began taking applications directly, some 170,000 additional people have signed up for Precheck. The program appears on track, but if more travelers don’t sign up TSA will have to scale back the number of Precheck lanes at airports, Mr. Pistole said. TSA hasn’t set an optimum number of enrollees for the program, he said.
How heavily should a firm use its resources? Resources — be they people, equipment, or facilities — are expensive so there is an obvious case to be made for keeping utilization rates as high as possible. But there is also something to be said for not pushing utilization too high. Many systems need some slack to work well. It is slack that allows firms to absorb the unpredictable or to address problems that go beyond immediate firefighting. That is the point of a recent Strategy & Business article (Cut Your Company’s Fat but Keep Some Slack, Spring 2014). The authors main point is that “slack is routinely undervalued.”
Here is the example given to lead off the article.
In 2002, the operating rooms at St. John’s Regional Health Center, an acute-care hospital in Missouri, were at 100 percent capacity. When emergency cases—which made up about 20 percent of the full load—arose, the hospital was forced to bump long-scheduled surgeries. As a result, according to one study, doctors often waited several hours to perform two-hour procedures and sometimes operated at 2 a.m., and staff members regularly worked unplanned overtime. The hospital was constantly behind.
Administrators brought in an outside advisor, who came up with a rather surprising solution: Leave one room unused. To many, this seemed crazy. The facility was already being squeezed, and now comes a recommendation to take away even more capacity? Yet there was a profound logic to this recommendation, a logic that is instructive for the management of scarcity.
On the surface, St. John’s lacked operating rooms. But what it actually lacked was the ability to accommodate emergencies. Because planned procedures were taking up all the rooms, unplanned surgeries required a continual rearranging of the schedule—which had serious repercussions for costs and even quality of care. The key to finding a solution was the fact that the term unplanned surgery is a bit misleading. The hospital can’t predict each individual procedure, but it knows that there will always be emergencies. Once a room was set aside specifically for unscheduled cases, all the other operating rooms could be packed well and proceed unencumbered by surprises. The empty room thus added much-needed slack to the system. Soon after implementing this plan, the hospital was able to accommodate 5.1 percent more surgical cases overall, the number of surgeries performed after 3 p.m. fell by 45 percent, and revenue increased. And in the two years that followed, the hospital experienced a 7 and 11 percent annual increase in surgical volume.
I have a long-standing interest in Black Friday — less because I want to go shopping but more because it poses some interesting questions on how firms compete and how they manage customers. The news this year is that Black Friday is creeping evermore into Thanksgiving proper as retailers keep moving up their opening times. So why are they doing that? Two posts on Businessweek.com put forward theories. The first posits that this is being driven by customer segmentation (The Game Theory Behind Macy’s Thanksgiving Opening, Oct 15).
Traditions are being trampled on by the Corporate Retail Complex! Of course, consumers don’t have to go. Some won’t, and that’s precisely what the strategy folks at Macy’s are betting on.
The purists scandalized by the thought of shopping on the holiday itself aren’t likely to avoid Macy’s altogether. And with the die-hard bargain-hunters swarming the stores on Thursday, Friday shopping will likely be much more pleasant for those who are a little less committed.
Much has been written Angela Ahrendts leaving Burberry to take over Apple’s retail operations but the Guardian has something of a unique take. They argue that a pressing concern is simply managing the queue for tech support (Apple stores await Ahrendts touch as outlets struggle with growing demand, Oct 18).
It’s only a two-hour wait. An ordinary Thursday afternoon at Apple’s flagship UK store in Regent Street, London and a long line of customers snakes across the first floor. The hip technology brand is used to queues for the launch of its latest must-have product, but these people have come carrying faulty iPhones and malfunctioning laptops, desperate for help from one of Apple’s increasingly hard to reach “Genius” experts.
When it opened in Virginia in 2001, the first Apple store was hailed as a retail revolution, allowing shoppers to play with expensive technology without any sales pressure. The emphasis on service, with blue-shirted Geniuses on hand to answer queries and fix broken products, has become almost as important to the Apple brand as the aesthetic appeal of its products. But the whole experience is under pressure as a relatively small number of shops struggle to cope with rapidly growing customer numbers. …
The Regent Street outlet, for example, employs at least 120 Geniuses. Each sees up to 30 customers a day but it is impossible to book an appointment less than a week in advance. If the problem is urgent you can turn up and queue, but it could be a very long wait. This week, a gaggle of well-trained, polite and friendly staff worked their way along the line trying to answer simple queries and advise people on alternatives to queueing. But it is hard to redirect people when every nearby shop has its Geniuses fully booked for days on end.
The article goes on to note that this is not just an issue in London. It certainly can be an issue here in Chicagoland. While a quick check of my nearest Apple store shows that they currently have a number of appointments open for tomorrow, Friday morning already has no availability. There are even reports of scalpers hawking Genius Bar reservations in China.
So is there an easy fix to this problem? It seems like there are two issues here. First, to what extent should Apple accommodate walk-in customers? Second, is there any easy fix to expanding Genius capacity? These are related. If capacity is expanded then the ease of getting a reservation should take care of the walk-in issue. On the other hand, if capacity cannot be easily expanded, then there is a question of how to allocate it between walk-ins and appointments.
In the basement of the Kellogg School, there is a cafe. It’s a busy cafe, which says more about the available alternatives than about its absolute quality. Because it gets busy and because a good number of its customers are polite enough to walk out of class five minutes early to beat the crowd, I and my colleagues have learned that it is a much better to plan to go down for a sandwich a little before noon than a little after noon. According to CNBC, Goldman Sachs faces similar issues with queuing in its cafeteria and it actively tries to manage the system (The creepy capital efficiency of Goldman’s cafeteria, Oct 17).
The most crowded time of the day to eat lunch is, naturally, during lunch time. For most people, this falls around noon. This creates the phenomenon of the lunchtime rush hour. You know this all too well if you’ve ever tried to stop in your local chopped salad place at, say, 12:30 in the afternoon.
Goldman didn’t like the idea of its people waiting on long lines to get their lunch. People are capital to Goldman. It wants to use its capital efficiently. Standing on line waiting for dumplings or salad or a burger is not an efficient use of Goldman’s capital. …
The cafeteria has a set of timed discounts. If you show up in the cafeteria before 11:30 or after 1:30, you get a 25 percent discount on your food. Goldman incentivizes employees to avoid the rush hour.
Fast food is supposed to be, well, fast. But is speed everything? If you think about how different chains advertise, they are often emphasizing price or some expansion of their offerings. Essentially no one ever says that they will get you on your way in two minutes. Speed is taken as a given but there has to be some interplay between the range of what a firm offers and how fast they can serve customers.
That gets us to QSR Magazine‘s annual survey of drive-thru lane performance (The Drive-Thru Performance Study, Oct 2013). Drive thrus matter since they can account for 60 – 70% of sales and QSR’s survey is something of an industry standard since they have been at it for 15 years. You can find information on their methodology here and a paper co-written by Gady that uses this data here. The most interesting insight from the survey comes from comparing data on service times (i.e., how long does it take from when you get to the order board until you have your bag of food) this year with last year.
It’s been a while since we have written about long delays to clear immigration control at airports. But as this eye candy from the Wall Street Journal makes clear, it is time to revisit the topic (The Summer of Long Customs Waits, Jun 12).
In a nutshell, lines are getting longer and longer. (Also, don’t fly through Miami. Check out this video.)
So what is going on? (more…)
How much would you spend to skip a line at a theme park? At Universal Studios Hollywood at least some people are willing to pony up a lot (At Theme Parks, a V.I.P. Ticket to Ride, New York Times, Jun 10).
As stratification becomes more pronounced in all corners of America, from air travel to Broadway shows to health care, theme parks in recent years have been adopting a similarly tiered model, with special access and perks for those willing to pay.
Now Universal Studios Hollywood has pushed the practice to a new level.
It has introduced a $299 V.I.P. ticket, just in time for the summer high season, that comes with valet parking, breakfast in a luxury lounge, special access to Universal’s back lot, unlimited line-skipping and a fancy lunch. …
Universal upgraded its V.I.P. Experience — and raised the price by 50 percent — after realizing that the old one, which did not include lunch, the lounge or other perks, “was selling out more and more frequently,” Ms. Wiley said.
Apparently, the New York Hilton Midtown will no longer be offering room service. So customers will no longer have the option of ordering cookies and milk for $20. That’s got to be a lucrative business, right? Maybe not. Check out this report from Marketplace (How does a $25 room service burger not make money?, Jun 3).
This quote from the report gets to the heart of the problem.
“It’s very rare, if not impossible, for hotels to produce revenue in terms of room service,” says Mehmet Erdem, professor at the Harrah College of Hotel Administration at University of Nevada, Las Vegas.
Hotels typically lose money keeping a full kitchen and wait staff on standby. That’s the key reason hospitality watchers believe hotels are killing room service. In many cases, that means job cuts for hotel workers, 55 at the New York Hilton alone. For its part, Hilton says it’s ending room service because of declining demand.