<s>
In	O
software	O
engineering	O
and	O
software	B-Architecture
architecture	I-Architecture
design	O
,	O
architectural	B-Architecture
decisions	I-Architecture
are	O
design	O
decisions	O
that	O
address	O
architecturally	B-Architecture
significant	I-Architecture
requirements	I-Architecture
;	O
they	O
are	O
perceived	O
as	O
hard	O
to	O
make	O
and/or	O
costly	O
to	O
change	O
.	O
</s>
<s>
Architectural	B-Architecture
decisions	I-Architecture
influence	O
and	O
impact	O
the	O
non-functional	O
characteristics	O
of	O
a	O
system	O
.	O
</s>
<s>
Each	O
architectural	B-Architecture
decision	I-Architecture
describes	O
a	O
concrete	O
,	O
architecturally	O
significant	O
design	O
issue	O
(	O
a.k.a.	O
</s>
<s>
An	O
architectural	B-Architecture
decision	I-Architecture
captures	O
the	O
result	O
of	O
a	O
conscious	O
,	O
often	O
collaborative	O
option	O
selection	O
process	O
and	O
provides	O
design	O
rationale	O
for	O
the	O
decision	O
making	O
outcome	O
,	O
e.g.	O
,	O
by	O
referencing	O
one	O
or	O
more	O
of	O
the	O
quality	O
attributes	O
addressed	O
by	O
the	O
architectural	B-Architecture
decision	I-Architecture
and	O
answering	O
"	O
why	O
"	O
questions	O
about	O
the	O
design	O
and	O
option	O
selection	O
.	O
</s>
<s>
Architectural	B-Architecture
decisions	I-Architecture
concern	O
a	O
software	O
system	O
as	O
a	O
whole	O
,	O
or	O
one	O
or	O
more	O
of	O
the	O
core	O
components	O
of	O
such	O
a	O
system	O
.	O
</s>
<s>
Types	O
of	O
architectural	B-Architecture
decisions	I-Architecture
are	O
the	O
selection	O
of	O
architectural	O
tactics	O
and	O
patterns	O
,	O
of	O
integration	O
technologies	O
,	O
and	O
of	O
middleware	O
,	O
as	O
well	O
as	O
related	O
implementation	O
strategies	O
and	O
assets	O
(	O
both	O
commercial	O
products	O
and	O
open	O
source	O
projects	O
)	O
.	O
</s>
<s>
Software	B-Architecture
architecture	I-Architecture
design	O
is	O
a	O
wicked	O
problem	O
,	O
therefore	O
architectural	B-Architecture
decisions	I-Architecture
are	O
difficult	O
to	O
get	O
right	O
.	O
</s>
<s>
Architectural	B-Architecture
decision	I-Architecture
making	O
is	O
a	O
core	O
responsibility	O
of	O
software	O
architects	O
;	O
additional	O
motivation	O
for/of	O
the	O
importance	O
of	O
architectural	B-Architecture
decisions	I-Architecture
as	O
a	O
first-class	O
concept	O
in	O
software	B-Architecture
architecture	I-Architecture
can	O
be	O
found	O
online	O
.	O
</s>
<s>
Rationale	O
was	O
mentioned	O
in	O
an	O
early	O
definition	O
of	O
software	B-Architecture
architecture	I-Architecture
by	O
Perry/Woolf	O
,	O
but	O
not	O
researched	O
much	O
until	O
2004	O
,	O
when	O
a	O
workshop	O
on	O
architectural	B-Architecture
decisions	I-Architecture
and	O
Architectural	O
Knowledge	O
Management	O
was	O
held	O
in	O
Groningen	O
,	O
NL	O
.	O
</s>
<s>
From	O
2006	O
on	O
,	O
the	O
architectural	O
knowledge	O
management	O
and	O
architectural	B-Architecture
decision	I-Architecture
research	O
communities	O
gained	O
momentum	O
and	O
a	O
number	O
of	O
papers	O
was	O
published	O
at	O
major	O
software	B-Architecture
architecture	I-Architecture
conferences	O
such	O
as	O
European	O
Conference	O
on	O
Software	B-Architecture
Architecture	I-Architecture
(	O
ECSA	O
)	O
,	O
Quality	O
of	O
Software	B-Architecture
Architecture	I-Architecture
(	O
QoSA	O
)	O
and	O
(	O
Working	O
)	O
International	O
Conference	O
on	O
Software	B-Architecture
Architecture	I-Architecture
(	O
ICSA	O
)	O
.	O
</s>
<s>
The	O
most	O
recent	O
standard	O
for	O
architecture	O
descriptions	O
,	O
ISO/IEC/IEEE	O
42010:2011	O
has	O
a	O
dedicated	O
rationale	O
entity	O
,	O
and	O
gives	O
detailed	O
recommendations	O
which	O
architectural	B-Architecture
decisions	I-Architecture
to	O
capture	O
and	O
which	O
properties	O
of	O
an	O
architectural	B-Architecture
decision	I-Architecture
to	O
record	O
in	O
the	O
decision	O
log	O
.	O
</s>
<s>
A	O
number	O
of	O
decision	O
making	O
techniques	O
exists	O
,	O
both	O
general	O
ones	O
and	O
software	O
and	O
software	B-Architecture
architecture	I-Architecture
specific	O
ones	O
,	O
for	O
instance	O
,	O
dialogue	O
mapping	O
.	O
</s>
<s>
Architectural	B-Architecture
decisions	I-Architecture
are	O
used	O
in	O
software	O
design	O
;	O
hence	O
they	O
have	O
to	O
be	O
communicated	O
to	O
,	O
and	O
accepted	O
by	O
,	O
the	O
stakeholders	O
of	O
the	O
system	O
that	O
fund	O
,	O
develop	O
,	O
and	O
operate	O
it	O
.	O
</s>
<s>
Architectural	B-Architecture
decisions	I-Architecture
also	O
have	O
to	O
be	O
considered	O
when	O
modernizing	O
a	O
software	O
system	O
in	O
software	O
evolution	O
.	O
</s>
<s>
Many	O
architectural	B-Architecture
decisions	I-Architecture
recur	O
across	O
projects	O
;	O
hence	O
,	O
experiences	O
with	O
past	O
decisions	O
,	O
both	O
good	O
and	O
bad	O
,	O
can	O
be	O
valuable	O
reusable	O
assets	O
when	O
employing	O
an	O
explicit	O
knowledge	O
management	O
strategy	O
.	O
</s>
<s>
It	O
is	O
important	O
to	O
known	O
when	O
a	O
single	O
architectural	B-Architecture
decision	I-Architecture
can	O
be	O
considered	O
done	O
.	O
</s>
<s>
On	O
large	O
scale	O
projects	O
,	O
the	O
number	O
of	O
architectural	B-Architecture
decisions	I-Architecture
to	O
be	O
made	O
can	O
exceed	O
100	O
,	O
including	O
:	O
</s>
<s>
Refer	O
to	O
the	O
design	O
concept	O
catalogs	O
in	O
Attribute-Driven	B-Architecture
Design	I-Architecture
3.0	O
and	O
domain-specific	O
decision	O
guidance	O
models	O
for	O
more	O
examples	O
.	O
</s>
<s>
Many	O
templates	O
have	O
been	O
suggested	O
by	O
practicing	O
architects	O
and	O
by	O
software	B-Architecture
architecture	I-Architecture
researchers	O
.	O
</s>
<s>
GitHub	O
repositories	O
such	O
as	O
"	O
Architecture	O
decision	O
record	O
(	O
ADR	O
)	O
"	O
and	O
"	O
Markdown	O
Architectural	B-Architecture
Decision	I-Architecture
Records	O
"	O
collect	O
many	O
of	O
them	O
,	O
as	O
well	O
as	O
links	O
to	O
tools	O
and	O
writing	O
hints	O
.	O
</s>
<s>
Both	O
practitioners	O
and	O
researchers	O
recognize	O
that	O
software	B-Architecture
architecture	I-Architecture
decision-making	O
is	O
a	O
group	O
process	O
that	O
involves	O
several	O
stakeholders	O
discussing	O
,	O
evaluating	O
and	O
shortlisting	O
architectural	B-Architecture
decisions	I-Architecture
.	O
</s>
<s>
These	O
challenges	O
provide	O
good	O
scope	O
for	O
experimentation	O
and	O
research	O
for	O
the	O
software	B-Architecture
architecture	I-Architecture
community	O
.	O
</s>
