Cafe queue abandonment scenario calculator

Calculate served customers and abandoned customers with your own figures.

Your numbers

Use the units shown. Results update as you change valid inputs.

Use served customers and abandoned customers to compare changes to your inputs. The method and limits below explain the scope.

Examples

Examples

Try the starting example

Arrival times (minutes)
0,1,2,3
Service durations (minutes)
4,4,2,2
Maximum tolerated waits (minutes)
5,2,2,4
Servers (count)
1
Served customers (count)
3
Abandoned customers (count)
1
Customer queue outcomes (JSON)
[{"item":1,"server":1,"start":0,"end":4,"wait":0,"abandoned":false},{"item":2,"server":1,"start":null,"end":null,"wait":3,"abandoned":true},{"item":3,"server":1,"start":4,"end":6,"wait":2,"abandoned":false},{"item":4,"server":1,"start":6,"end":8,"wait":3,"abandoned":false}]

Try another scenario

Arrival times (minutes)
0,0,1,2
Service durations (minutes)
3,3,3,3
Maximum tolerated waits (minutes)
0,1,2,3
Servers (count)
2
Served customers (count)
4
Abandoned customers (count)
0
Customer queue outcomes (JSON)
[{"item":1,"server":1,"start":0,"end":3,"wait":0,"abandoned":false},{"item":2,"server":2,"start":0,"end":3,"wait":0,"abandoned":false},{"item":3,"server":1,"start":3,"end":6,"wait":2,"abandoned":false},{"item":4,"server":2,"start":3,"end":6,"wait":1,"abandoned":false}]
Calculation method

Calculation method

Served customers (count)

Simulate FCFS earliest-free-server; customer abandons when start−arrival>patience.

Abandoned customers (count)

Count records above their patience threshold.

Customer queue outcomes (JSON)

Return station,start,end,modeled wait and abandonment for each arrival.

Symbols and units
a
Arrival times (minutes)
b
Service durations (minutes)
c
Maximum tolerated waits (minutes)
d
Servers (count)

Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.

Assumptions & limits

Assumptions & limits

  • FCFS service with per-customer patience; abandon if predicted wait strictly exceeds entered threshold, before reserving server. Supported limits: All numeric inputs and computed intermediates must remain finite. Supported numeric input magnitude is zero or 1e-12 through 1e12 in absolute value; reject values outside this bounded range. All lists/JSON record tables are limited to 100 records unless a stricter bound is stated; reject malformed record arity and wrong member types. Equal nonempty lists; arrivals and patience>=0, service>0; servers 1..20.
Are these inputs private?

These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.

Share this page
Share this calculator

Leave unchecked to share the page without your entered values.