Operations

Service level target In queueing, a goal stated as a share of parties served within a set time, such as 80 percent served...

Utilization The share of time stations or staff are busy serving, equal to arrival rate divided by total service...

Service rate How many parties one station or server can finish per unit of time, written μ (mu) in queueing formu...

Arrival rate How many parties arrive or join a queue per unit of time, written λ (lambda) in queueing formulas. I...

Little's law The queueing rule L = λW: the average number of parties in a system (L) equals the arrival rate (λ)...

Perceived wait How long a wait feels to the party, as opposed to the actual wait on the clock. It shrinks when the...

Queue psychology The study of how waiting feels compared with how long it lasts. Its best-known findings: occupied ti...

Jockeying A party switching from one queue to another that looks faster, as shoppers do between checkout lanes...

Reneging A party joining a queue and then leaving before being served, usually because the wait ran longer th...

Balking A party seeing the queue or the quoted wait and deciding not to join at all. Balking is lost demand...

Queue discipline The rule that decides which waiting party is served next: first come first served, priority by class...

Priority queue A queue in which some parties are called ahead of others by a set rule rather than by arrival order...

First come, first served (FIFO) The queue discipline that serves parties in the order they joined; FIFO means first in, first out. I...

Remote queue Joining a queue before arriving, from a phone or website, so the party's wait starts while they trav...

Virtual queue A queue that holds each party's place digitally instead of in a physical line, so parties can wait e...

Double booking Two reservations placed on the same resource at the same time, such as one provider or one table. It...

Overbooking Accepting more reservations than capacity on purpose, expecting some parties not to arrive. The amou...

Appointment slot A fixed block of time on a calendar that one party can book, such as a 30-minute slot with a provide...

Triage Sorting arriving parties by urgency or need before service order is decided, so that the most urgent...

Host The staff member who greets parties, adds them to the queue, quotes waits and seats or calls them in...