The waiting line is a list of customers who remains waiting for getting certain goods or services from service center. Understanding waiting lines or queues and learning how to manage them is one of the most important areas in operation management. In organizations or in personal life, there are examples of processes which generates waiting lines or queues. Such waiting lines occur because the current services facility is insufficient to provide service at that instance. For examples: on traveling by airplanes, we have first had experiences with several types of waiting lines (queues). To buy tickets, we may have to stand in line at travel agent's office. When we arrive at airport we stand in line to check baggage then we stand in line again to get a seat assignment. We line up again (once more) for a security check and the again in the boarding lounge before entering the airplane. When we are inside the plane, we wait for those ahead of us to take their seats. The plane it self waits for take off clearance, when it arrives at its destination it may circle sometime waiting for landing clearance. And finally, we may wait for baggage to arrive and then for ground transportation. The goal of queuing is essentially to minimize total costs. There are two basic categories of cost in a queuing situation: - i) Cost of customer waiting for service ii) Cost of service capacity.
The cost of customer waiting include the Salaries paid to employees while they wait for services (machines waiting for tools, the driver of truck waiting to unload); any loss of business due to customer refusing to wait and possibly going elsewhere in future and the cost of space for waiting (fuel consumed by planes waiting to land).
The cost of service capacity includes, the no of checkouts at a supermarkets , the no of repair people to handle equipment to breakdowns etc can be defined as the costs of maintaining the ability to produce service. These two