Discrete events
Arrivals and service completions move the system forward. A shared waiting line feeds the first available service channel.
AN INTERACTIVE LABORATORY FOR THE SCIENCE OF WAITING
See how variability and service capacity shape a waiting line. Change the inputs, watch customers arrive and leave, and connect the live simulation to queueing theory.

01 / PRODUCT OVERVIEW
Why can a line grow even when average capacity seems sufficient? What changes when you add a server or reduce variability?
Queue Lab puts those questions into a browser experiment. A discrete-event simulation drives the customer animation and empirical distributions, while analytical reference values make the connection between the experiment and operations-management concepts visible.
02 / USER WORKFLOW
Select Poisson, exponential, normal, or constant arrival and service settings. Adjust rates and the spread of normal times.
Choose one to ten service channels and an unlimited or finite waiting room. Try café, bank, call-center, steady-service, or overloaded presets.
Run the animated queue, pause, advance one event, change speed, or fast-forward through 2,000 customers.
Read live performance measures, distributions, and theory. Compare parallel channels with a single faster channel of equal total capacity.
03 / SIMULATION & ANALYTICAL LOGIC
The laboratory displays queue length, customers in service, throughput, and turnaways alongside distributions and simulated-versus-theoretical performance.
Arrivals and service completions move the system forward. A shared waiting line feeds the first available service channel.
Single-server formulas and Erlang C provide reference values for stable systems with exponential interarrival and service times.
A birth–death calculation handles limited line capacity and the probability that an arriving customer is turned away.
For general or constant times with unlimited waiting space, the app uses an Allen–Cunneen approximation. Interface labels distinguish approximations and reference values.
04 / TEACHING & EXPERIMENTATION
Compare a café with one service channel, a bank with several tellers, or a call center with limited waiting capacity. Observe the relationship between utilization, congestion, and customer experience.
Explore how changing variability affects waiting times, examine simulated distributions, and compare one fast server with multiple parallel servers at equal total capacity.
05 / TRY THE APPLICATION
Queue Lab runs directly in your browser with no account or API key. Start with a preset, adjust one input, and compare the resulting behavior. The app is an educational simulation; theoretical comparisons depend on the assumptions shown in the interface.