Transcript Clicker_chapter27.ppt

Statistical Process Control
BPS chapter 27
© 2006 W.H. Freeman and Company
Flowcharts
In the following flowchart,
what happens if the
“check for size” is not
O.K.?
a)
b)
c)
d)
Deburr
Heat billet to the required
temperature.
Check to see if oversize.
Scrap.
Flowcharts (answer)
In the following flowchart,
what happens if the
“check for size” is not
O.K.?
a)
b)
c)
d)
Deburr
Heat billet to the required
temperature.
Check to see if
oversize.
Scrap.
Flowcharts
In the following flowchart,
what happens if the item
is oversized?
a)
b)
c)
d)
Scrap.
Bar code and store.
Heat billet to required
temperature.
Cut to the billet length.
Flowcharts (answer)
In the following flowchart,
what happens if the item
is oversized?
a)
b)
c)
d)
Scrap.
Bar code and store.
Heat billet to required
temperature.
Cut to the billet length.
Control charts
True or false? Once the mean and standard deviation have been
determined for a process by careful observations over a long period
of time, then this mean and standard will always be correct for this
process.
a)
b)
True
False
Control charts (answer)
True or false? Once the mean and standard deviation have been
determined for a process by careful observations over a long period
of time, then this mean and standard will always be correct for this
process.
a)
b)
True
False
Control charts
Which control chart should you look at first?
a)
b)
c)
x
s
p
Control charts (answer)
Which control chart should you look at first?
a)
b)
c)
x
s
p
s control charts
Which is an example of a cause that would affect the variation shown
on an s control chart?
a)
b)
c)
A new employee’s first day on the job, when he sometimes does
well and sometimes doesn’t.
A gradual loosening of a screw on a piece of equipment.
A switch from oak to maple for the wood used in the manufacturing
process.
s control charts (answer)
Which is an example of a cause that would affect the variation shown
on an s control chart?
a)
b)
c)
A new employee’s first day on the job, when he sometimes
does well and sometimes doesn’t.
A gradual loosening of a screw on a piece of equipment.
A switch from oak to maple for the wood used in the manufacturing
process.
x control charts
Which is an example of a cause that would affect the variation shown
on an x control chart?
a)
b)
c)
A new employee’s first day on the job, when he sometimes does
well and sometimes doesn’t.
A gradual loosening of a screw on a piece of equipment.
Combining results from several different employees in a single
sample.
x control charts (answer)
Which is an example of a cause that would affect the variation shown
on an x control chart?
a)
b)
c)
A new employee’s first day on the job, when he sometimes does
well and sometimes doesn’t.
A gradual loosening of a screw on a piece of equipment.
Combining results from several different employees in a single
sample.
Loss of control
Why don’t we want to add lots of signals to help us detect various kinds
of loss of control?




The more signals you have, the more false alarms you will have.
Too many signals cancel each other out.
Signals are hard to implement.
We do want as many signals as possible.
Loss of control (answer)
Why don’t we want to add lots of signals to help us detect various kinds
of loss of control?




The more signals you have, the more false alarms you will
have.
Too many signals cancel each other out.
Signals are hard to implement.
We do want as many signals as possible.
Control charts
True or false? When setting up a control chart, you should use a
“target value” for the process standard deviation  instead of
estimating from past data.
a)
b)
True
False
Control charts (answer)
True or false? When setting up a control chart, you should use a
“target value” for the process standard deviation  instead of
estimating from past data.
a)
b)
True
False
Control charts
True or false? It is better and less expensive to inspect the final
product than to take small samples at each of the key
manufacturing points and to check that those steps are in control.
a)
b)
c)
True
False
Impossible to answer unless more is known about the
manufacturing process.
Control charts (answer)
True or false? It is better and less expensive to inspect the final
product than to take small samples at each of the key
manufacturing points and to check that those steps are in control.
a)
b)
c)
True
False
Impossible to answer unless more is known about the
manufacturing process.
Capability
Which is a true statement about capability?
a)
b)
c)
d)
If a process is in control, we know that it has adequate capability.
If a process is not in control, we know that it does not have
adequate capability.
If a process is not in control, we would have a hard time telling if it is
capable.
A variable that continues to be described by the same distribution
when observed over time is said to be capable.
Capability (answer)
Which is a true statement about capability?
a)
b)
c)
d)
If a process is in control, we know that it has adequate capability.
If a process is not in control, we know that it does not have
adequate capability.
If a process is not in control, we would have a hard time telling
if it is capable.
A variable that continues to be described by the same distribution
when observed over time is said to be capable.