Erlang B

Verb: erlangB

Applies the Erlang B formula using a rule of three, taking the empty field in one of the Calls per hour, Lines and Blocking probability parameters to calculate the result.


erlangB [--callsperhour(Numeric)] [--lines(Numeric)] [--blockingprobability(Numeric)] [--callretries(Numeric)] (Boolean)=success (Numeric)=blockingProbability (Numeric)=busyHourTraffic (Numeric)=lines (Numeric)=callLoss


Script Designer Required AcceptedTypes Description
--callsperhour Calls per hour Optional Number Amount of phone calls during the busiest hours.
--lines Lines Optional Number Number of available telephone agents.
--blockingprobability Blocking probability Optional Number Probability of blocking a telephone line.
--callretries Retries Optional Number Probability of retrying a previously blocked call.


Script Designer AcceptedTypes Description
success Success Boolean Returns "True" if the command executed successfully, or "False" otherwise.
blockingProbability Blocking probability Number Probability of a telephone line being blocked.
busyHourTraffic Calls per hour Number Maximum amount of calls during the busiest hour.
lines Lines Number Amount of agents needed to answer calls.
callLoss Missed calls Number Probability of missed calls.


Applies the Erlang B, returning Blocking probability, Calls per hour, Lines and Missed calls.

defVar --name success --type Boolean
defVar --name blockingProbability --type Numeric
defVar --name lines --type Numeric
defVar --name missedCalls --type Numeric
defVar --name callsPerHour --type Numeric
// Erlang B Formula.
erlangB --callsperhour 400 --lines 40 success=success blockingProbability=blockingProbability callsPerHour=busyHourTraffic lines=lines missedCalls=callLoss
logMessage --message "Success: ${success}\r\nBlocking probability: ${blockingProbability} \r\nCalls per hour: ${callsPerHour}\r\nLines: ${lines}\r\nMissed calls: ${missedCalls}" --type "Info"
// Success: True
// Blocking Probability: 0.882 
// Calls per hour: 396.792
// Lines: 47
// Missed calls: 0


The Blocking probability, Retries input parameters and the Missed calls output parameters, use decimal values from 0 to 1, going from 0% to 100%.

See Also

  • Erlang C
  • Rule of 3