The document discusses software as an economic activity and the challenges of software growth. It notes that software cannot grow exponentially because the cost of maintaining software grows exponentially. It also notes that software exhibits entropy, with its value diminishing over time. The document explores software lifecycles and economics, observing that software growth diminishes in value at around 1.5 years per version. It discusses improving by reducing errors over time through learning from mistakes.

1. Deeper
thoughts,
Context
of
L5
Think
Process

2. • Recap
• Summarize
last
class
leanings
–
Any
one
• Last
Class
Quiz..
• Agenda
this
class
– SoDware
as
economic
acFvity

3. THINK
PROCESS……benefits
• Problems
are
caused
by
the
system
• About
85
%
of
the
problems
are
caused
by
the
system,
not
the
people.
• Process
is
about
people
• People
develop
their
potenFal
more
fully
and
are
more
effecFve
within
the
organizaFon.
• How
GOOD
is
about
maturity
• By
defining,
measuring,
and
controlling
the
process,
improvements
are
more
focused,
successful
and
sustained.
• Mature
Process
is
the
tool
for
Successful
Change
management
– The
likelihood
increases
of
new
technology,
techniques,
and
tools
being
introduced
successfully.
By:BS

4. SoDware
as
an
Economic
AcFvity
• AYribute
soDware
in
terms
of....
–
Value
• Who
Values
and
How?,
lifeFme
cost?
–
Price
• Who
determines
and
hoe
(Cost
+
Model)
–
ROI
• How
do
you
demonstrate
ROI
at
proposal
Fme,
Model

5. By:BS
Visibility
and
Support
Application Lifecycle
Legacy DeclineLegacy EnhancementsLegacy Active
Operation and Maintenance
Migration
• Technology Change
• Process Change
• Platform Change
SoDware
Economics.
Lifecycle
Development
Prototype(α) Release(β)
Phase
Cost
period
Focus
0.05x 0.25x 0.3x 0.2x 0.1x
6 to 9 months 36 to 60 months
Sunset
R.O.I -VE (Invest) Null +VE (Reap) -VE(Retire)
Corrective Perfective Productive PreventiveAdaptive
Handoffs Team-1 Team-2 Team-3 Team-4
Indicative
Figures..

6. By:BS
SW
Growth
diminishes
Value
(IP)
at 1.5 year / version
SoDware
Exhibits
Entropy

7. By:BS
Effect:
SW
Growth
Rules:
S
n+1
=
2
to
1.5
×
S
n
per
year
[HennesseyP:90]
V
n+1
≤
1.30%
×
V
n
[Bernstein:03]
V
n+1
=
V
n
+
V
1
[Roux:97]
[earlier
indicaFons]
Deletion of prior code = 5% per year [W:04]
at 1.5 year / version

8. By:BS
ObservaFons
• SoDware
cannot
grow
exponenFally
Because
1. Cost
of
maintaining
soDware
grows
exponenFally
[Brooks:95]
2. Can't
afford
to
hire
staff
at
exponenFal
*2
3. Cannot
have
large
fracFon
of
changes
in
a
version
4. Cannot
impose
version
changes
on
users
<
1
/
year
5. DeleFng
code
is
risky
and
of
liYle
benefit
except
in
game
/
embedded
code
no
Moore's
Law
for
SoDware

9. By:BS
How
do
you
improve
?
Well,
it's
plain
and
simple
to
express
Err
and
err
and
err
again
but
less
and
less
and
less…Road
to
Wisdom
– Pete
Hein,
Danish
Poet
and
Mathema1cian

10. By:BS
Benefits
of
CMM
Src: Carnegie mellon University