Error Messages

The Queueing ToolPak is designed to give diagnostic error messages when possible. Error messages appear in cells where a Queueing ToolPak function is entered with inappropriate arguments.  The list below shows all error messages generated by the Queueing ToolPak in alphabetical order.

We may not have anticipated all possible errors, so the absence of an error message should not be taken as a guarantee that the number is accurate. Also, for some errors, we were unable to display a diagnostic error message. Instead, "#VALUE," "#NUM!" or some other error message generated by Excel may appear.

#arrival rate < 0: You used an arrival rate that was less than zero.  The arrival rate must be greater than or equal to zero.

#insufficient system capacity: The system capacity is insufficient to achieve the desired level of service.  Two ways to avoid this are to increase the system capacity or decrease the desired level of service.

#not implemented: You entered a finite queue capacity as an argument for one of the QTPGGS_ functions.  The current version of QTP does not perform calculations for finite capacity G/G/s systems.

#queue capacity < 0: You entered a queue capacity that was less than or equal to zero.  The queue capacity must be a whole number that is greater than or equal to zero.

#queue capacity not integer: You entered a queue capacity that was not a whole number.  The queue capacity must be a whole number.

#servers <= 0: You entered a number of servers that was less than or equal to zero.  The number of servers must be greater than zero.

#servers not integer: You entered a number of servers that was not a whole number.  The number of servers must be a whole number that is greater than zero.

#service level <= 0: You used a service level that was less than or equal to zero.  The service level must be greater than zero.

#service level >= 1: You entered a service level that was greater or equal to 1 (=100%).  The service level must be less than 100%.  (A 100% service level would require infinitely many servers.)

#service rate <= 0: You used a service rate that was less than or equal to zero.  The service rate must be greater than zero.

#state < 0: You entered a system state that was less than zero.  The system state must be a whole number that is greater than or equal to zero.

#state not integer: You entered a system state that was not a whole number.  The system state must be a whole number.

#stdev arrivals < 0: You entered a standard deviation of interarrival times that was less than zero.  This standard deviation must be greater than or equal to zero.

#stdev service < 0: You entered a standard deviation of service times that was less than zero.  This standard deviation must be greater than or equal to zero.

#system capacity <= 0: You entered a system capacity that was less than or equal to zero.  The system capacity must be a whole number that is greater than or equal to 1.

#system capacity not integer: You entered a system capacity that was not a whole number.  The system capacity must be a whole number.

#threshold time < 0: You used a threshold time that was less than zero.  The threshold time must be greater than or equal to zero.

#utilization >= 100%: The arguments you used resulted in the quantity Arrival Rate / (Servers * Service Rate) being 100% or greater. This would lead to a queue that grows indefinitely.  Three ways to avoid this are to increase the arrival rate, increase the number of servers, or increase the service rate. 

#<argument> parameter error: You entered an argument that QTP did not understand (for example, a string instead of a number).  Instead of <argument>, the error message will tell you the name of the argument that QTP did not understand.

Home