I was jokingly referring to the fact that every Walmart I have ever been to is understaffed in the front, so I always end up waiting in line for 10 minutes behind Walmartians buying the most random crap you can imagine while the cashiers perform at what can only be described as a glacial pace.
Having been a Walmart cashier for three summers, I want to step in here and point out that
(a) they do use software to generate a massive number of shifts in need of filling each week;
(b) they then assign employees to fill these roughly equally (ie equal proportion of empty slots at all times);
(c) the employees work a different schedule literally every day (sometimes I would have this sequence: 8am-5pm, 2pm-11pm, 4pm-9pm) just because the computer says to;
(d) I am a speedy checker and as efficient and awesome as my WNFF persona suggests, but:
(e) the main cause of slowness is idiot customers, for example:(e.i) old fogeys who want you to cash in coupons that expired in 1971 [this ACTUALLY HAPPENED to me - it was two cents off];
(e.ii) other old fogeys who pay by check;
(e.iii) moms who forgot milk and send their 8-year-old daughter to get some milk and say "Don't worry, she runs fast";
(e.iv) people who say "Oh, I thought I was buying [some other thing]. I don't want that";
(e.v) young women who see how much the clothes cost, say, "Oh," and then start saying, "Okay, I don't want that, or that, or that, or that... now how much is it?";
(f) and most relevantly to the original post, the leading reason that Walmarts are understaffed is not "bad computer simulation" but "nobody wants to work in a goddamn Walmart."