<s>
In	O
statistical	O
quality	O
control	O
,	O
the	O
u-chart	B-Application
is	O
a	O
type	O
of	O
control	B-General_Concept
chart	I-General_Concept
used	O
to	O
monitor	O
"	O
count	O
"	O
-type	O
data	O
where	O
the	O
sample	O
size	O
is	O
greater	O
than	O
one	O
,	O
typically	O
the	O
average	O
number	O
of	O
nonconformities	O
per	O
unit	O
.	O
</s>
<s>
The	O
u-chart	B-Application
differs	O
from	O
the	O
c-chart	B-Application
in	O
that	O
it	O
accounts	O
for	O
the	O
possibility	O
that	O
the	O
number	O
or	O
size	O
of	O
inspection	O
units	O
for	O
which	O
nonconformities	O
are	O
to	O
be	O
counted	O
may	O
vary	O
.	O
</s>
<s>
Examples	O
of	O
processes	O
suitable	O
for	O
monitoring	O
with	O
a	O
u-chart	B-Application
include	O
:	O
</s>
<s>
As	O
with	O
the	O
c-chart	B-Application
,	O
the	O
Poisson	O
distribution	O
is	O
the	O
basis	O
for	O
the	O
chart	O
and	O
requires	O
the	O
same	O
assumptions	O
.	O
</s>
