Amos Redfern

Lecturer. The arithmetic half of the course, from Little's Law to the scheduler inside your laptop.

Role

Lecturer

Affiliation

Slop University, School of Invented Disciplines

Office

Pemberton Building, room 2.06

Phone

+61 2 5550 3072

Email

amos.redfern@slop.university

Consultation

Thursdays 10:00 to 12:00, slots bookable, walk-ins taken if a slot is free

At Slop since

2019

Elsewhere

• Staff profile
• Code and course notebooks

Email with a photo of your working, not a description of it. I can debug an equation I can see.

I came to queues through operating systems, which is a strange door to come through and a useful one. A CPU scheduler and a passport office solve the same problem, and the operating system has the better documentation.

My half of the course is the part students expect to be the hard part. It is not. There are four pieces of arithmetic in twelve weeks and you have met three of them before. What makes them hard is that they keep telling you things about the world you would rather not know, such as the fact that a counter running at 95 percent capacity is not a well-run counter.

What to ask me about#

Ask me about the arithmetic, obviously. Ask me as well about the week 9 trace, which is the only complete record of a queue you will get all semester and which most people underuse.

If you are stuck on Kingman, bring the numbers rather than the question. Nine times out of ten the problem is that the service times are bimodal and nobody has looked at the histogram.

Consultation#

Thursdays, 10:00 to 12:00. Book a slot through the course page or take your chances at the door.

Teaching this semester

Lectures

• Little's LawWeek 2
• Variability is the taxWeek 3
• One line or manyWeek 4
• Machines that waitWeek 9
• When the queue is the hazardWeek 10

Field sessions

• The long tailWeek 3
• Reading a scheduler traceWeek 9

Interests

• Scheduler design and starvation
• Heavy-tailed service time distributions
• Backpressure in human systems
• Teaching approximation without teaching proof

Selected publications

• 2026Ageing applied to a service counter, and who it costs. Slop University Working Papers in Applied Waiting.
• 2025Kingman is an approximation and your students should say so. Proceedings of the Invented Disciplines Teaching Forum.
• 2023Finding Little's Law in a scheduler trace. Journal of Invented Disciplines.

Awards

• 2025Faculty Teaching Citation. Slop University School of Invented Disciplines.