SCM 300 - MODULE 05 Questions with Correct Answers (Grade
A+)
Question 1: Goal of waiting line management
Answer: Balance the cost paid by the cus- tomers (time) with the cost paid by the company (money paid to
maintain the system).
Question 2: Parts of a waiting line system
Answer: input source, waiting line, ser- vice facility
Question 3: Input Source
Answer: this is the population of people that might want service
Question 4: Waiting Line
Answer: The area which customers wait for service
Question 5: Service Facility
Answer: The area in which customers ac- tually receive service
Question 6: 4 Managerial Considerations in Queues
Answer: Customers - How many are there? How quickly are they ar- riving? The waiting lines - What type
of lines? How many lines? Employees - Who's working in the system? How many? Skill lev- el and speed?
Service facilities - How ettec- tive and eflcient is the process? Tools?
Question 7: Basic waiting line terminology
Answer: *queue*: line. *channel*: line. refers to the number of lines available at each step. *phase*: a
single step in a process. *infinite population of cus- tomers*: the number of possible customers that may
come into the store is very high (or unlim- ited.) When a customer enters the system, the odds of another
entering the system are not im- pacted in any significant man- ner. *finite population of cus- tomers*: The
number of cus- tomers is limited. Example: If you have a bus company that has 10 busses, then your com-
pany's repair shop has a finite population of 10 busses. If 1 bus is in the shop only 9 others are left in the
population. The odds of a 2nd bus entering the system decline. *balking*: when a potential cus- tomer sees
the line, but never joins the line because they think it looks too long and/or too slow *reneging*: when a
customer joins the line, gets frustrated and leaves the line
Page 1
, Question 8: Single-server formulas and calculations (in text: a sampling queuing model)
Answer: Not provided in source.
Question 9: Arrival (Lambda) rates: define and calculate
Answer: number of customers arriving / unit of time
Question 10: Service (Mu) rates): define and calculate
Answer: number of customers helped / unit of time
Question 11: Percentage of Time Worker is Busy
Answer: rho = lambda/ mu
Question 12: average number of customers in the line (nl)
Answer: = rho[lambda/(mu-lambda)]
Question 13: average amount of time a customer waits in the line (tl)
Answer: rho[1/(mu-lambda)]
Question 14: average number of customers in the system (ns)
Answer: lambda/(mu-lambda)
Question 15: average amount of time a customer spends in the system (ts)
Answer: 1/(mu-lambda)
Page 2
A+)
Question 1: Goal of waiting line management
Answer: Balance the cost paid by the cus- tomers (time) with the cost paid by the company (money paid to
maintain the system).
Question 2: Parts of a waiting line system
Answer: input source, waiting line, ser- vice facility
Question 3: Input Source
Answer: this is the population of people that might want service
Question 4: Waiting Line
Answer: The area which customers wait for service
Question 5: Service Facility
Answer: The area in which customers ac- tually receive service
Question 6: 4 Managerial Considerations in Queues
Answer: Customers - How many are there? How quickly are they ar- riving? The waiting lines - What type
of lines? How many lines? Employees - Who's working in the system? How many? Skill lev- el and speed?
Service facilities - How ettec- tive and eflcient is the process? Tools?
Question 7: Basic waiting line terminology
Answer: *queue*: line. *channel*: line. refers to the number of lines available at each step. *phase*: a
single step in a process. *infinite population of cus- tomers*: the number of possible customers that may
come into the store is very high (or unlim- ited.) When a customer enters the system, the odds of another
entering the system are not im- pacted in any significant man- ner. *finite population of cus- tomers*: The
number of cus- tomers is limited. Example: If you have a bus company that has 10 busses, then your com-
pany's repair shop has a finite population of 10 busses. If 1 bus is in the shop only 9 others are left in the
population. The odds of a 2nd bus entering the system decline. *balking*: when a potential cus- tomer sees
the line, but never joins the line because they think it looks too long and/or too slow *reneging*: when a
customer joins the line, gets frustrated and leaves the line
Page 1
, Question 8: Single-server formulas and calculations (in text: a sampling queuing model)
Answer: Not provided in source.
Question 9: Arrival (Lambda) rates: define and calculate
Answer: number of customers arriving / unit of time
Question 10: Service (Mu) rates): define and calculate
Answer: number of customers helped / unit of time
Question 11: Percentage of Time Worker is Busy
Answer: rho = lambda/ mu
Question 12: average number of customers in the line (nl)
Answer: = rho[lambda/(mu-lambda)]
Question 13: average amount of time a customer waits in the line (tl)
Answer: rho[1/(mu-lambda)]
Question 14: average number of customers in the system (ns)
Answer: lambda/(mu-lambda)
Question 15: average amount of time a customer spends in the system (ts)
Answer: 1/(mu-lambda)
Page 2