Feeds:
Posts
Comments

Archive for the ‘capacity management’ Category

Escalators are back in the news! A little over a year ago, Transport for London (i.e., the London Tube) got some press for an experiment they ran essentially prohibiting people from walking up the escalators at one of their stations. (We posted about that here.) Now the New York Times has seen fit to revisit the topic (Why You Shouldn’t Walk on Escalators, Apr 4). The Times’ definitive stance has not gone unchallenged. Indeed, Gizmodo has an essay taking the opposite side (Why You Should Always Walk on Escalators, Apr 4).

The source of controversy here is that Transport for London found that escalators moved more people per hour and delays to get on the escalators were shorter when people were kept from walking up the stairs. This is obviously a paradox. From an individual point of view, walking up the stairs has to be faster. If each individual can move faster, how can the overall wait be worse?

(more…)

Read Full Post »

This should not surprise you at all: Christmas is a big deal for Lego. According to the Financial Times, half of the company’s sales come in the month or so before the holiday (Lego makes push to avoid disappointments of Christmas past, Dec 22). But how do they gear up for that big peak in sales? Check out the video below:

(more…)

Read Full Post »

I have been teaching the MBA core operations class this quarter. This week we just wrapped up talking about bottlenecks and capacity. I consequently found an article in The Guardian rather timely (The tube at a standstill: why TfL stopped people walking up the escalators, Jan 16). TfL in the article title refers to “Transport for London” which runs the Underground. The article reports on an experiment run at their Holborn station.

The experiment in question gets to a bit of escalator etiquette. Specifically, when using an escalator, should people stand to one side so those in a hurry (or in need of a work out) can walk up the escalator or should people patiently stand two abreast? Now if you prefer to chug up the stairs, you clearly lose under the second scenario. However, can it be the case that accommodating the walkers cost the system as a whole an unacceptable amount of capacity?

It’s all very well keeping one side of the escalator clear for people in a rush, but in stations with long, steep walkways, only a small proportion are likely to be willing to climb. In lots of places, with short escalators or minimal congestion, this doesn’t much matter. But a 2002 study of escalator capacity on the Underground found that on machines such as those at Holborn, with a vertical height of 24 metres, only 40% would even contemplate it. By encouraging their preference, TfL effectively halves the capacity of the escalator in question, and creates significantly more crowding below, slowing everyone down.

(more…)

Read Full Post »

%d bloggers like this: