Monday, November 14, 2011

Uncool and unLean taxi batching at Logan Airport

One of the things you learn from Lean is that batch processing is often inefficient and wasteful compared to continuous flow processes.  I have sometimes used this blog to illustrate this phenomenon, like at this bakery and, ironically, even at the food service line of a Lean conference.

I saw another example when I arrived at Logan Airport late at night this past week and was waiting for a taxi.  Here's the scene behind me.  Counting those in front of me, at least 50 people were in line at Terminal B, with more showing up every minute.

Taxis were arriving in groups of three to five as they were sent over from the parking lot at which they are required to wait.  In between, the dispatcher required all passengers to wait behind a chain.  (By the way, note the signage!)

Then the taxis arrived and parked at the curb. 

Only then would the dispatcher allow the batch of three to five passengers groups past the chain.  It would take them about a minute to reach their cabs, load their luggage, and sit inside.  Since the cab at the front of the line was furthest from the chain, its passenger would have the longest distance to walk and take the most time to load. 

Only after that first cab was filled and ready to leave could any of the ones behind it proceed to leave.

In between batches, the dispatcher had nothing to do. He even had time to visit a passing MassPort supervisor driving by in his SUV.

I was about number 40 in line when I arrived at the scene.  It took me over a half hour to get into a cab using this approach.  Each batch had three to five cabs, arriving every three to five minutes.  Loading took a minute for each batch.  I had to wait for eight to ten batches. 

Imagine a simple improvement to this system.  Assuming the taxis have to come over in batches from their parking lot, why not have the dispatcher get people ready to load by standing at pre-marked spots along the sidewalk, ready to load luggage and hop in as soon as a car pulled up.

But imagine a further enhancement.  I asked my cab driver, "Did you have to wait a long time at the remote parking lot before being freed up?"  "No," he said, "only about 15 minutes."  I was stunned that this could be the case on a very busy night, with unmet demand at each terminal.

Apparently the overall dispatcher at the parking lot sends a clump of cabs to each terminal, in sequence, when it is a busy night.  With five terminal locations, every fifth group will show up at any given terminal, always in a batch.  That batch takes time to exit the parking lot, and then the next group moves up the line from their parking places.  What if, instead, the dispatcher at the parking lot sent each single cab, on a continuous basis, to the next terminal in sequence?  A steady flow of individual cabs would arrive at each terminal, separated by less than a minute, to be entered by a waiting passenger at the curb.

I'll let our process flow engineers do the math, but I guarantee this approach would have reduced waiting times considerably, both for cab drivers trying to make a living by getting as many trips as possible and for passengers trying to get home as quickly as possible.


Almond Dhukka said...

Had a similar experience this morning when I got in on the redeye from Denver. Waited for 20min (4th batch in line) before the first group of cabs came (and there were 8 of them by my count when they did come). Didn't realize it's something they actually "control" to be that way. =/

Mark Graban said...

Having flown into Logan a lot, the taxi dispatcher role seems like a classic "make work" job that adds no value. Even when there is no line, there are no taxis and you have to wait for that dispatcher to radio for a car. At other airports, the taxis are just queued up.

Bob said...

I went to Las Vegas recently for the VHA improvement forum. There is a long line of waiting passengers but the dispatcher sends people to designated pre marked spots to stand to wait for the next cab. The passenger is already at the spot when the cab arrives. Just as suggested in the article. There were a few hundred in line but it went very quickly considering the volume of people.

Paul Levy said...

From Facebook:

Beverly H Rogers: You remind me of my dad, who was a Lean expert before Lean was invented. His 'targets' didn't always appreciate it though.

Samantha Riley: Hope you gave them some advice!!!

Alex Stiber said...

From Facebook:

But, Paul, have you considered that perhaps there's another goal: to maintain consistency throughout the customer's entire "airline experience"? The only thing that surprises me is that they haven't found a way to make you wait in line to get out of your cab and into your home at the end of it all.

Alex Stiber said...

Truly a classic example of failing to see things in a new way. My guess is that when you operate in an environment in which queuing is normative, the first "solution" that naturally comes to mind in addressing a "problem" is more queuing. And since it's normative, culturally consistent, there's no reason to question its relative merits against (unimagined) alternatives.

Anonymous said...

The reason for making people line up behind the railing and not at spots along the curb is that a number of people, over the past 10 years, have been injured, and I believe at least one killed, by cabs that jumped the curb or plowed into the cab in front of them. The cabs must now come to a full stop and the keys removed from the ignition before patrons are allowed past the yellow chain.

Paul Levy said...


Claudia said...

Power trip for the dispatcher....

Richard said...

I know that the Atlanta airport has the passenger waiting in a numbered sport on the curb for the cab to arrive and the “flow in”, so it can be done.

Anonymous said...

The justification for instituting this process several years ago is that a pedestrian was killed in an accident at a taxi loading stand.

My take is that with 3 million passengers per year coming through the airport, one pedestrian death every couple of years sounds like a pretty close to perfect safety record; certainly not worth instituting a process change that results in hundreds of thousands of wasted hours of people's lives every year.

@BostonLogan Boston Logan Airport said...

From Twitter:

Like how u que at Disney.Curb safety=1st concern.Curbs r tricky when u mix cabs w/pax.Suggestion has merit.Will share w/ops staff.

Paul Levy said...

My reply:

@BostonLogan Thx, worth contacting folks at Lean Enterprise Institute in Cambridge, a non-profit that offer advice and assistance.

Paul Levy said...

Meanwhile, over at Universal Hub, which picked up this post, we have the following interplay the first few commenters. (More here:

By anon - 11/15/11 - 9:23 am

This guy is a meatball, take the 5 minute walk to the next terminal where a line of vacant taxis will be waiting.

I fly out of logan every month, sometime two to three times, and never have had to wait longer than the walk between terminals.

Blame the victim much?
By anon - 11/15/11 - 11:25 am

Why is he "a meatball"?

Why should the passenger have to walk to the next terminal instead of asking Massport to simply do its job well?

And you are supposed to know . . .
By anon - 11/15/11 - 11:42 am

where the other terminal is and how many cabs are there, how? At 11pm?

Of course ...
By SwirlyGrrl - 11/15/11 - 12:19 pm

... everyone who uses Logan Armpit just *knows* how the *system* works.

Not that anybody would ever arrive at an international airport from out of town or anything like that ...

By JCK - 11/15/11 - 12:05 pm

It seems like there has to a better answer than "walk to the next terminal."

While your advice is probably good in practice under the current circumstances, there's nothing to prevent Logan from managing their taxi queue more effectively, other than the "this is the way we've always done it" mentality.

Barry Carol said...

When the cab dispatcher has no competition and probably can’t be fired, at least not without a cumbersome due process procedure, efficiency and customer service are likely to be sub-optimal. It would probably take perceived loss of convention and tourist business with airport cab service cited as a contributing factor to get the attention of people in a position to effect positive change.

Gary Kantor said...

Thanks, Paul. We're going to take your Logan airport story and use it to teach "flow" as part of our improvement campaign in South Africa ( Hope that's OK with you!

Gary Kantor
Cape Town
S Africa

Paul Levy said...

Wonderful, Gary. Do a search on this blog under "lean" and you will find lots of hopsital-specific examples, too. Best of luck!