<s>
System	B-General_Concept
appreciation	I-General_Concept
is	O
an	O
activity	O
often	O
included	O
in	O
the	O
maintenance	O
phase	O
of	O
software	B-General_Concept
engineering	I-General_Concept
projects	O
.	O
</s>
<s>
Key	O
deliverables	O
from	O
this	O
phase	O
include	O
documentation	O
that	O
describes	O
what	O
the	O
system	O
does	O
in	O
terms	O
of	O
its	O
functional	O
features	O
,	O
and	O
how	O
it	O
achieves	O
those	O
features	O
in	O
terms	O
of	O
its	O
architecture	B-Architecture
and	O
design	O
.	O
</s>
<s>
Software	B-Architecture
architecture	I-Architecture
recovery	I-Architecture
is	O
often	O
the	O
first	O
step	O
within	O
System	B-General_Concept
appreciation	I-General_Concept
.	O
</s>
