Is the express lane in the grocery store always the fastest lane?
That’s a great question and its the subject of a “Dear Mona” column over on FiveThirtyEight (Dear Mona, Which Is The Fastest Check-Out Lane At The Grocery Store?, Oct 16). Mona attacks this question by heading into the queuing theory weeds.
I couldn’t find much research on express lanes specifically, but one paper from Amsterdam found the reduction in wait times for express-lane customers didn’t offset the overall increase in wait times for everyone. Maybe life would be easier if the supermarket didn’t have an express lane — or, better yet, if it got rid of multiple lines altogether and had all customers join a single infinitely sprawling line where there were no winners and losers. That might sound nightmarish, but the math actually suggests it would be anything but.
That math comes from queuing theory, a subject of study that’s been around ever since Danish mathematician Agner Krarup Erlang discovered a method for managing telephone traffic in 1909. To answer your question, I’ve had to take a crash course in (more modern) queuing theory, including examining formulae that calculate how average wait times at the grocery store vary depending on the type of line you join.
I should state upfront Mona on the whole acquits herself quite well on this. But there are a couple of points worth mentioning. First, there in fact supermarkets that run with a single queue, like this Hannaford’s in West Lebanon, NH.
As you can see, that singe serpentine queue ends up chewing up a lot of space at the front of the store. That’s a lot of real estate to give up when you only have two people in line. As we have written about before, that is only one of the complications of having a single queue in a grocery setting.
But let’s suppose for the moment that we can get a single queue to work. Is that in fact the best way to run a supermarket’s checkout? (more…)
Read Full Post »
Wal-Mart has had a tough go over the last few years. Sure, they are still a huge force in retailing but they have run into a variety of operational problems largely related to in-store execution. (See. for example, this post.) Now the Wall Street Journal reports that Wal-Mart is gearing up for the holidays by trying to address some customer service pain points (Returning to Wal-Mart: Human Cashiers, Aug 15).
In an attempt to lure more customers this holiday season, Wal-Mart Stores Inc. is promising to staff each of its cash register from the day after Thanksgiving through the days just before Christmas during peak shopping times.
The move, called the “checkout promise,” is aimed at addressing one of the retailer’s biggest customer complaints: long waits in checkout lines, which can cause even more frustration when positions aren’t fully staffed. The pledge will cover hours typically on weekend afternoons but which can vary by store.
“We feel good about price and having the top gifts of the season, so the next priority is about getting customers in and out of the stores quickly,” Duncan Mac Naughton, Wal-Mart’s chief merchandising officer, said in an interview. “Taking the possibility of waiting in long lines off the table will attract more people into stores.” …
On Thursday the retail giant said it allocated more hours to the front end of the store, to overnight stocking, and to deli and bakery to improve customer service during the most recent quarter.
Here are two questions that are worth thinking about. (more…)
Read Full Post »
Why do you stand in line? In many Western countries, that is a silly question. You stand in line because that is what you do. Whether waiting to check out at the supermarket or get into a ballgame, standing in line is the norm. You stand in line because everyone else is standing in line. However, as a National Post article points out, standing in line is very much a cultural phenomenon and not just some inherent human trait (Everyone line up: Canada’s tradition of orderly queuing ‘foreign and strange’ to many newcomers, Jul 25).
“Lining up is seen as a universal sort of truth,” said J.J. McCullough, the Vancouver-based author of J.J.’s Complete Guide to Canada, an online primer for newcomers. “And if someone doesn’t adhere to the protocol then it must be because they’re uncouth or uncivilized, rather that this is a sort of idiosyncratic tradition that we’ve internalized.” …
At the Canadian School of Protocol and Etiquette, located in London, Ont., lineup training comes on the same day students are taught about North American-style introductions. Students are taught where to line up, how to maintain one’s proper place in the lineup and — most importantly — how close to stand.
“In certain cultures, queue etiquette is just not on the radar,” said school director Wendy Mencel.
So where does this tradition come from?
Read Full Post »
Posted in Airlines, Government, Queue management, Services, tagged Airlines, airports, Priorities, Queues, Supply Chain, TSA, Waiting Time on July 28, 2014 |
Leave a Comment »
Have you ever wished you could tell the TSA what to do with itself? Now, you have that opportunity — at least when it comes to how they organize and manage their queues. To make things even better, they might actually pay you! The Transportation Security Administration has posted a challenge asking for people to develop a simulation model to tackle the capacity management issues of getting people through airport security. If you are interested in the challenge, the official call is here. Here are some of the specific considerations that need to be tackled:
TSA is looking for the Next Generation Checkpoint Queue Design Model to apply a scientific and simulation modeling approach to meet the dynamic security screening environment. The new queue design should include, but not limited to the following queue lanes:
- TSA Pre✓™
- Premier Passengers (1st class, business class, frequent fliers, etc.)
- Employee and Flight Crews
- PWD (wheelchair access)
The Challenge is to provide a simulation modeling concept that can form the basis to plan, develop requirements, and design a queue appropriately. The concept will be used to develop a model to be applied in decision analysis and to take in considerations of site specific requirements, peak and non-peak hours, flight schedules and TSA staffing schedules. Solvers are expected to provide the concept and provide evidence that it works as described in the requirements.
According to Nextgov.com, there are specific performance targets for different classes of customers (Attention, Passengers: $15,000 Prize for Whoever Can Speed TSA Screening, Jul 18)
The line, in this scenario, extends from the point where a passenger joins the end of the queue to the metal detector or body scan machine.
The rules for the challenge state wait times cannot be more than 5 minutes for PreCheck and 10 minutes for standard lines.
Read Full Post »
Have you ever heard of VidCon? Turns out it is, in the words of Wikipedia, “a multi-genre online video convention, held annually in Southern California since 2010. Originally conceived by Hank and John Green of the “Vlogbrothers” YouTube channel, the convention is the largest of its kind in the world, gathering thousands of online video viewers, creators, and industry representatives worldwide.”
My wife and I had never heard of it either until our teenage daughter (who for the sake of this post we’ll call Magenta) put on the full-court press to attend. For better or worse, we caved and today Magenta is Anaheim for the start of the conference with her mom in tow. They have in hand tickets that were purchased months ago. However, they also need to get their IDs for the conference. That was the first order of business today and led to a text I received a little before 9:00AM central time (which, allow me to point out, is not quite 7:00AM in Anaheim):
Just what does the longest line that Magenta’s Mom has ever seen look like? Take a gander (and see if you can spot Magenta).
So why bring this up? Beyond being able to publicly thank Magenta’s Mom for falling on this particular parenting grenade, it serves as a nice lead in to a recent Business Insider article on “Why People Wait In Hours-Long Lines For Shake Shack, Cronuts, And iPhones” (Jun 25). (more…)
Read Full Post »
Posted in Airlines, Priority queues, Queue management, Services, tagged Airlines, airports, Priorities, Queues, Services, TSA on April 17, 2014 |
1 Comment »
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.
Read Full Post »
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.
Read Full Post »