<s>
In	O
statistical	O
quality	O
control	O
,	O
the	O
individual/moving	O
-range	O
chart	O
is	O
a	O
type	O
of	O
control	B-General_Concept
chart	I-General_Concept
used	O
to	O
monitor	O
variables	O
data	O
from	O
a	O
business	O
or	O
industrial	O
process	O
for	O
which	O
it	O
is	O
impractical	O
to	O
use	O
rational	O
subgroups	O
.	O
</s>
<s>
The	O
"	O
chart	O
"	O
actually	O
consists	O
of	O
a	O
pair	O
of	O
charts	O
:	O
one	O
,	O
the	O
individuals	B-Application
chart	I-Application
,	O
displays	O
the	O
individual	O
measured	O
values	O
;	O
the	O
other	O
,	O
the	O
moving	B-Application
range	I-Application
chart	I-Application
,	O
displays	O
the	O
difference	O
from	O
one	O
point	O
to	O
the	O
next	O
.	O
</s>
<s>
As	O
with	O
other	O
control	B-General_Concept
charts	I-General_Concept
,	O
these	O
two	O
charts	O
enable	O
the	O
user	O
to	O
monitor	O
a	O
process	O
for	O
shifts	O
in	O
the	O
process	O
that	O
alter	O
the	O
mean	O
or	O
variance	O
of	O
the	O
measured	O
statistic	O
.	O
</s>
<s>
As	O
with	O
other	O
control	B-General_Concept
charts	I-General_Concept
,	O
the	O
individuals	O
and	O
moving	B-Application
range	I-Application
charts	I-Application
consist	O
of	O
points	O
plotted	O
with	O
the	O
control	O
limits	O
,	O
or	O
natural	O
process	O
limits	O
.	O
</s>
<s>
If	O
the	O
data	O
are	O
normally	O
distributed	O
with	O
standard	O
deviation	O
then	O
the	O
expected	O
value	O
of	O
is	O
,	O
the	O
mean	B-General_Concept
absolute	I-General_Concept
difference	I-General_Concept
of	O
the	O
normal	O
distribution	O
.	O
</s>
<s>
The	O
resulting	O
plots	O
are	O
analyzed	O
as	O
for	O
other	O
control	B-General_Concept
charts	I-General_Concept
,	O
using	O
the	O
rules	O
that	O
are	O
deemed	O
appropriate	O
for	O
the	O
process	O
and	O
the	O
desired	O
level	O
of	O
control	O
.	O
</s>
<s>
Performing	O
such	O
software	B-Application
validation	I-Application
is	O
generally	O
a	O
good	O
idea	O
with	O
any	O
SPC	O
software	O
.	O
</s>
