Waiting line analysis: Operating characteristics are: average values for characteristics that describe the performance of a waiting line system.
Waiting lines form because people/things (customers) arrive at the server faster than they can be served. They arrive at random times, and the time to serve each customer is different.
In a waiting line, we have the calling population, arrivals, servers and the waiting line or queue. The calling population is the customer that wants service from an operation. It is the source of customers to the waiting line system and it can be either infinite or finite. Infinite means that there is a large number of potential customers, and it is always possible for one more customer to arrive to be served. Finite means that there is a specific, countable number of potential customers.
The arrival rate (lambda) is rate at which customers arrive at service facility during a specified period. Estimated from empirical data derived from studying the system or a similar system, or it can be an average of these empirical data. Arrivals are assumed to be independent of each other and vary randomly over time. We assume there is no balking (refusing to join a line), reneging (leaving a line), or jockeying (changing lines) by customers in the waiting line system. We also assume that arrival late is less than service rate (or else line would grow infinitely long). Queue discipline → order in which customers are served. Most common type: first-come, first-serve. We also have last-in, first-out. Random queue. Prearranged schedule. Alphabetical order. Shortest expected processing times. Most critical problem. Two types of queue sizes: infinite or finite. Infinite could be of any size with no upper limit (most common size). Finite is limited in size.
Service times: arrivals are described in terms of rate, and service in