Operations and Supply Chain Winter Session Test 1 Chapter 10

limited-size customer pool that will use the service and, at times, form a line

Finite Population

population large enough so that the population size caused by subtractions or additions to the population does not significantly affect the system probabilities

Infinite Population

Length of the Lines:

Infinite potential length, limited line capacity

Under (2), we encounter two structures that differ in directional low requirements. The irst is similar to the multichannel- multiphase case, except that (a) there may be switching from one channel to the next after the irst service has been rendered and (b) the number of channels and phases may vary—again—after performance of the irst service.

Mixed. Under this general heading we consider two subcategories: (1) multiple-to- single channel structures and (2) alternative path structures.

The admission of patients in a hospital fol- lows this pattern because a speciic sequence of steps is usually followed: making initial contact at the admissions desk, illing out forms, making identiication tags, obtaining a room assignment, escorting the patient to the room, and so forth. B

Multi Channel Multi Phase

Tellers' windows in a bank and checkout counters in high-volume department stores exemplify this type of structure. T

Multi Channel Single Phase

a priority rule or set of rules for determining the order of service to customers in a waiting line

Queue Discipline

arrive view wait a minuet then leave

Rampant

Poiddon Ditribution

Service

A car wash is an illustration because a series of ser- vices (vacuuming, wetting, washing, rinsing, drying, window cleaning, and parking) is performed in a fairly uniform sequence.

Single Channel Multi Phase

A typical example of a single-channel, single- phase situation is the one-person barbershop.

Single Channel, Single Phase

Number of Lines

Single or Multiple

(T/F) Reducing waiting time costs money

T

Source population and the way customers arrive at the system The servicing system The condition of the customers exiting the system

The Queing System

How can we affect service time?

Using faster or slower servers

arrival probabilities described statistically

Variable (random) arrival distrubutions

When people waiting are employees,__________________________________________ When people waiting are customers, ______________________________________________________. What is an example of a low value?

it is easy to value their time./it is more difficult to value their time./ low sales

Exponential Distrubtion

Arrival

What are three more arrival characteristics?

Arrival Patterns, size of arrival units, degree of patience

the number of units arriving per period

Arrival Rate

arrive, view leave

Balking

What are the two types of service time distributions?

Constant (service provided by automation), Variable (service provided by humans, descibed using exponential distribution)

: periodic, with exactly the same time between successive arrivals

Constant Arrival Distribution

The Queing System

Customers Arrive, Customers are Served and customers leave

What are two important variables of waiting lines?

number of arrivals and how many people you can serve

A central problem in many service settings is the management ___________________________________.

of waiting in time

How can we control arrivals?

short lines, specific hours for specific customers, specialsU

When a customer leaves its position of a finite group as a member of the population, _________________________.

the size of the user group is reduced by one.