Determining the number of workstations required to provide a given level of service
A conveyor belt is used to feed parts to 10 workstations located along the conveyor belt. For convenience, it is assumed that travel along the belt between workstations is instantaneous. Parts arrive at the first workstation at a Poisson rate of 12 per minute. If the first station is busy, then the part moves to the second station, and so forth, until, finally, if all 10 workstations are busy, the part passes all workstations and is accumulated until the second shift, when it is processed by another workstation.
If the service times at the individual workstations are normally distributed with a mean of 45 seconds and a standard deviation of 5 seconds, what percentage of the parts will overflow the system?