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Lecture Operations management (6th Edition): Supp C - R. Dan Reid, Nada R. Sanders

This chapter explain the terms supply chain and logistics; name the key aspects of supply chain management; list, and briefly explain, current trends in supply chain management; outline the benefits and risks related to outsourcing;. | Supplement C - Waiting Line Models Operations Management 6th Edition R. Dan Reid & Nada R. Sanders 1 Copyright © 2016 John Wiley & Sons, Inc. Learning Objectives Describe the elements of a waiting line problem Use waiting line models to estimate system performance Use waiting line models to make managerial decisions Elements of Waiting Lines “Queuing system” is another name for a waiting line A waiting line system consists of two components: The customer population (people or objects to be processed) The process or service system Whenever demand exceeds available capacity, a waiting line or queue forms There is a tradeoff between cost and service level Waiting cost and service level trade-off The Customer Population Finite versus Infinite populations: Based on number of potential new customers materially affected by the number of customers already in queue Balking When an arriving customer chooses not to enter a queue because it’s already too long Reneging When a . | Supplement C - Waiting Line Models Operations Management 6th Edition R. Dan Reid & Nada R. Sanders 1 Copyright © 2016 John Wiley & Sons, Inc. Learning Objectives Describe the elements of a waiting line problem Use waiting line models to estimate system performance Use waiting line models to make managerial decisions Elements of Waiting Lines “Queuing system” is another name for a waiting line A waiting line system consists of two components: The customer population (people or objects to be processed) The process or service system Whenever demand exceeds available capacity, a waiting line or queue forms There is a tradeoff between cost and service level Waiting cost and service level trade-off The Customer Population Finite versus Infinite populations: Based on number of potential new customers materially affected by the number of customers already in queue Balking When an arriving customer chooses not to enter a queue because it’s already too long Reneging When a customer already in queue gives up and exits without being serviced Jockeying When a customer switches between alternate queues in an effort to reduce waiting time Service System The service system is defined by: The number of waiting lines The number of servers The arrangement of servers The arrival and service patterns The waiting line priority rules Service System: Number of Lines Waiting lines systems can have single or multiple queues Single queues avoid jockeying behavior and perceived fairness is usually high Multiple queues are often used when arriving customers have differing characteristics (e.g. paying with cash, less than 10 items, etc.) and can be readily segmented Service System: Number of Servers Single servers or multiple, parallel servers providing multiple channels Arrangement of servers (phases) Multiple phase systems require customers to visit more than one server Example of a multi-phase, multi-server system: Service System: Arrangement of Servers .