Practice MC

Question 1

Which term describes the actual time (i.e., including wait time) spent by a customer?
- throughput time
- rush order flow time
- total direct labour content
-direct labour utilization

Answer 1

Throughput time

Question 2

Which term describes the amount of labour expended on each customer?
- throughput time
- rush order flow time
- total direct labour content
- direct labour utilization

Answer 2

Total direct labour content

Question 3

Throughput is the same as the system
- cycle time
- rush order flow time
- capacity
- total direct labour content

Answer 3

Capacity

Question 4

What determines the system-wide cycle time?
- the bottleneck resource
- rush order flow time
- total direct labour content
- direct labour utilization

Answer 4

The bottleneck resource

Question 5

In general, how does increasing the number of workers in a work area affect the utilization?

Answer 5

Utilization decreases
= total direct labour content/(process cycle time)(# of workers)
Denominator increases, utilization becomes smaller

Question 6

If the standard deviation of a process decreases, how does the sigma level of a process change?

Answer 6

Increases, bell curve gets skinnier, sigma increases

Question 7

Which term can be translated as “idiot-proofing” or “mistake-proofing”?

Answer 7

Poka-yoke

Question 8

Sort

Answer 8

Seiri – eliminate obstacles and unnecessary items

Question 9

Set In Order

Answer 9

Seiton – arrange items for convenience, clarity, and smooth workflow

Question 10

Shine

Answer 10

Seiso – keep clean and safe; make problems easy to detect

Question 11

Standardize

Answer 11

Seiketsu –standardize best practices; make it easy to find things

Question 12

Sustain

Answer 12

Shitsuke –ensure clarity of standards; audit; promote training and discipline

Question 13

How does increasing the sample size affect the distance between the LCL and UCL? (Assume R-bar doesn’t change)

Answer 13

Narrows

Question 14

What do R charts depict?

Answer 14

The range (highest-lowest observation. How the range of the subgroups change over time.
- often used prior to X-chart in order to first see that variability is in control

Question 15

What do p-charts depict?

Answer 15

Estimate of population percentage (wa), error measured is a frequency/percentage

Question 16

What do X-bar charts depict?

Answer 16

How the mean or average changes over time

Question 17

Interarrival times are exponential with a mean of 25 seconds. What is the probability of the next arrival being within 50 seconds?

Answer 17

EXPON.DIST (50,0.04,TRUE)
1/25=0.04 arrival per second (we need a rate)

Question 18

Interarrival times are exponential with a mean of 25 seconds. What is the probability of 5 or more in the next 50 seconds?

Answer 18

1-POISSON.DIST (4,50*0.04,TRUE)
= 1-POISSON.DIST(4,2,TRUE)

Question 19

What does the Little’s Law variable Ws represent?

Answer 19

Average time in the system
Ls = λWs

Question 20

What does the Little’s Law variable Ls represent?

Answer 20

Average # of customers in the system
Ls = λWs

Question 21

What does the Little’s Law variable λ represent?

Answer 21

Average customer arrival rate
Ls = λWs

Question 22

If the throughput increases and the average time in the system is constant, what happens to the average number in the system?

Answer 22

Increases
Ls = λWs
If lambda increases, Ws stays the same, then Ls will increase the same amount of lambda (avg customer arrival rate)

Question 23

Which of the following relationships between how waiting times feel is NOT true?
- occupied time feels longer than unoccupied time
- anxiety makes waits feel longer
- pre-service waits feel longer than in-service waits
- unfair waits feel longer than fair waits

Answer 23

Occupied time feels longer than unoccupied time