In personalized queues, information at the level of individuals – customers or servers – is affecting system dynamics. Such information is becoming increasingly accessible, directly or statistically, as exemplified by personalized/precision medicine (customers) or call-center workforce management (servers). In the present work, we take advantage of personalized information about customers, spec...

This study investigates a random N-policy Geo/G/1 queue with startup and closedown times. N is newly determined every time a new cycle begins. When random N customers are accumulated, the server is immediately turned on but is temporarily unavailable to the waiting customers. It needs a startup time before starting providing service. After all customers in the system are served exhaustively, th...

We study a generalization of the GI/G/1 queue in which the server is turned off at the end of each busy period and is reactivated only when the sum of the service times of all waiting customers exceeds a given threshold of size D. Using the concept of a “randomly-selected” arriving customer, we obtain as our main result a relation that expresses the waitingtime distribution of customers in this...

In order to deliver assured Quality of Service (QoS) to the customer in terms of minimizing the expected waiting time in the queue; the service providers are putting a lot of effort. The varying calling pattern of the customers during different times of the day poses many challenging problems in terms of allocating the number of employees in an efficient manner to handle the customer’s calls. T...

We explore the issue of when and how to partition arriving customers into service groups that will be served separately, in a first-come first-served manner, by multi-server service systems having a provision for waiting, and how to assign an appropriate number of servers to each group. We assume that customers can be classified upon arrival, so that different service groups can have different ...

The vehicle routing problem with time windows (VRPTW) is an extension of the vehicle routing problem (VRP) with earliest, latest, and service times for customers. The VRPTW routes a set of vehicles to service customers having earliest, latest service times. The objective of the problem is to minimize the number of vehicles and the distance travelled to service the customers. The constraints of ...

We consider strategic arrivals to a FCFS service system that starts service at a fixed time and has to serve a fixed number of customers, e.g., an airplane boarding system. Arriving early induces a higher waiting cost (waiting before service begins) while arriving late induces a cost because earlier arrivals take the better seats. We first consider arrivals of heterogeneous customers that choos...

Abstract: We consider a perishable inventory system with bonus service for certain customers, wherein the demand of a customer is satisfied only after performing some service on the item which is assumed to be of random duration. The maximum inventory level is S . The ordering policy is (0,S ) policy and the lead time is zero. The life time of each items is assumed to be exponential.The custome...