A queueing system has four crews with three members each. The number of "servers" is:

4

Explanation:

A queuing system is put in place when customers require to be serviced from any business facility and the arrival of the customers and the service times are expected to be random. When there are four crews, all containing three members, four servers are required. When the servers are busy and new customers cannot get serviced upon arrival, they are expected to wait in line for the next available server.

The answer is 4.

The number of active servers is four for this four crew queuing system.

Explanation:

Now what is a queue management system?

As from the name it has some link with queue which means it's not something used once or twice.

It is a continuous process. In simple words, the number of processes increases and the severs get short and congested on this type of problem this management occurs.

It is always there to solve the problem of congestion the system.

Queuing management is concerned with queuing areas. Where there will a queue this system will be applied. And this queuing system is based on queuing theory.

Now what means by queuing areas?

It's a place where queues happen.

But what exactly is a queue?

You could say it's a line of something waiting for services or you can also say it as an application of "demands exceed the supply" problem.

Now consider queuing system where the number of active servers depends upon the the length of the queue.

As the length of the queue increases the number of active servers will increase and if the length of the queue decreases the number of active servers decreases.

On traditional scale the queuing theory, the theory on which this queuing system is based, there are fixed number of servers for each model as 10,25 or 19 servers.

Now if we see there is a queuing system has four crews with 3 members each.

Each crew will have its own one single active server so, there will be 4 active servers in this queuing system.