Monday, August 25, 2008

Tubular Bells (& Whistles)


In another life, I was a data-driven TQM, TQI number crunchin' fool. I don't particularly like statistics as a discipline (it requires discipline), but I do like goofing numbers around when the data suits me.

I took the raw logs from my beloved tube system for the month of July, and learned some interesting things. O.K., not interesting like guaranteed winning lottery numbers, interesting like "hey, look at that! Let's eat."

This post is dedicated to Nick, and his, er, seemingly indefatigable interest in this subject. I still don't know why.

I have to say that the repair that made all of the difference occurred on July 15, the middle of the month, so the data reflects both an ailing and a healthy system. I'm going to run these numbers again, for August, but I'll probably only share them with Nick. But let's not delay the suspense, any longer. . .

Total Number of Transactions: 18,070 (31 days)
Average # of transactions per hour: 24
(a transaction about every 2.5 minutes, if it were a constant)

118 Returns (0.65%) - a little more than 1/2 of 1% were sent back due to some system problem. Nearly always just resent, then they go. For a mechanical system run by a PC running Windows NT 4.0, I'd say that that's pretty good.

51% of transactions took less than 2 minutes
95% of transactions took less than 3 minutes
(this improved dramatically after 7/15, when the pressure/vacuum tripled).

63% of transactions were either to or from the Lab.
28% of transactions were either to or from the Pharmacy.
That makes 91%. That's a lot. See?

The hastily drawn chart, below, shows the volume of traffic by time of day!


I think it's interesting that, with only a couple of spikes, the traffic is rather constant. Lots of body fluid samples, lab results, drug orders and drugs whizzing back and forth, all day, all night, Mary Ann.

Well, those are the highlights, Nick old man. I don't think anybody's really realized just how busy this thing is, and how it's really serving these two departments so well. Kinda like one's sewer system (Kelly!) - you take if for granted right up to the moment when it stops working. I'm hoping it will spur the powers that be to up the ante on the stuff that needs to be upgraded on this thing before it 'craps out' , someday.

Let's Eat.