MBSE Presentation to the INCOSE UK Railway Interest Group

1. MBSE
–
is
there
any
substance
behind
the
hype?
James
Towers
Principal
consultant
-­‐
Object
Flow
Ltd
Chair
–
INCOSE
UK
Model
Based
Systems
Engineering
Working
Group
INCOSE
UK
Railway
Interest
Group,
October
2013
Copyright © 2013 by Object Flow Ltd. Published and used by INCOSE UK Ltd and INCOSE with permission.

2. IntroducPon
• Model-­‐based
Systems
Engineering
(MBSE)
is
generaPng
a
great
deal
of
interest
within
the
SE
community
-­‐
at
recent
INCOSE
InternaPonal
Symposia,
there
has
been
standing
room
only
at
MBSE
presentaPons.
The
UK
Chapter
set
up
an
MBSE
Working
Group
in
2012.
Right
from
the
very
first
meePng
it
became
apparent
that:
– The
term
MBSE
is
not
very
well
defined
or
understood.
– Some
Systems
Engineers
hold
the
view
that
there
is
no
(or
liYle)
disPncPon
between
MBSE
and
what
they
refer
to
as
“Good
Systems
Engineering”.
– Many
Systems
Engineers
currently
uPlise
diagrams
and
simulaPons
in
their
work
but
do
not
consider
they
are
doing
MBSE,
so
what's
the
difference?
MBSE
–
is
there
any
substance
behind
the
hype?
2

3. Quotes
• “Essen3ally,
all
models
are
wrong,
but
some
are
useful.”
– George
Box,
Empirical
Model-­‐Building
and
Response
Surfaces
(1987)
• “Experience
by
itself
teaches
nothing...Without
theory,
experience
has
no
meaning.
Without
theory,
one
has
no
ques3ons
to
ask.
Hence
without
theory
there
is
no
learning.”
– W.
Edwards
Deming,
The
New
Economics
for
Industry,
Government,
Educa3on
(1993)
• “Un
bon
croquis
vaut
mieux
qu'un
long
discours.”
(A
good
sketch
is
beUer
than
a
long
speech.)
– Napoléon
Bonaparte,
Quoted
in
L'Arche
de
Noé
(1968)
by
Marie-­‐Madeleine
Fourcade
MBSE
–
is
there
any
substance
behind
the
hype?
3

4. Roles
&
OrganisaPons
Consider the following concepts and relationships:
class Roles & Organisations
Name:
Author:
Version:
Created:
Updated:
Roles & Organisations
James Towers
1.0
03/10/2013 09:29:10
03/10/2013 10:20:36
Context
1
0..*
Fills
Person
0..*
MBSE
–
is
there
any
substance
behind
the
hype?
Comprises
Role
1..*
1..*
Organisation
1
4

5. About
me
obj ect About Me - James Tow ers
Worked
for
Nig el
Best
within
Brian
Halliday's
department
James Tow ers :
Person
WCRM Systems
Engineering :Context
Functional Modelling
Analyst :Role
2004 - Present :Context
Principal Consultant :
Role
Name:
Author:
Version:
Created:
Updated:
About Me - James Towers
James Towers
1.0
03/10/2013 10:06:17
03/10/2013 13:46:48
Netw ork Rail :
Organisation
Helping
org anisations
implement
model
based
techniques
Obj ect Flow Ltd :
Organisation
2012 - Present :Context
Chair :Role
MBSE
–
is
there
any
substance
behind
the
hype?
INCOSE UK MBSE
WG :Organisation
5

6. About
the
MBSE
WG
uc MBSE WG Context (Syndicate Group)
Name:
Author:
Version:
Created:
Updated:
MBSE WG Context (Syndicate Group)
Camm, Capel, Fletcher, Holt & Older
1.0
01/02/2013 17:16:33
02/10/2013 10:11:02
MBSE WG Context
«constrains»
Apply Cross Industry
Promote MBSE
Industry
«constrains»
People, Processes &
Tools
Identify Current
Practice
«include»
Disseminate
«constrains»
Prov ide Know ledge About
«include»
Ev aluate Current
Practice
Current Practice
Industry Group
«include»
Define Business
Case
Profesional Body
Publish
Present
...Research
Academia
MBSE
–
is
there
any
substance
behind
the
hype?
...Tools
...Best Practice
Standards
Organisaton
6

7. Mission
Statement
• The
aims
of
the
MBSE
WG
are
to:
– Promote
the
use
and
understanding
of
MBSE,
– Facilitate
and
improve
communicaPon
between
System
Engineers
pracPcing
MBSE,
– IdenPfy
and
catalogue
the
Tools,
Techniques
and
Languages
used,
– Provide
guidance
on
how
to
best
apply
MBSE
techniques
across
the
lifecycle,
and
– Support
the
MBSE
IniPaPve
run
by
INCOSE
Central
and
the
OMG.
MBSE
–
is
there
any
substance
behind
the
hype?
7

8. ParPcipaPng
OrganisaPons
object: Flow
Helping to build better Systems
MBSE
–
is
there
any
substance
behind
the
hype?
8

9. QuesPon
1
WHAT
IS
MBSE?
MBSE
–
is
there
any
substance
behind
the
hype?
9

10. Z9
–
“What
is
Model
Based
Systems
Engineering”
• INCOSE
UK
guide
Z9
defines
MBSE
as:
– The
formalised
applicaPon
of
modelling
to
support:
•
•
•
•
System
requirements
Analysis
Design
V&V
acPviPes
– Beginning
in
the
conceptual
design
phase
and
conPnuing
throughout
development
and
later
lifecycle
phases.
• Also:
– MBSE
is
a
model-­‐centric
approach
providing
a
single
point
of
truth
which
is
reflected
in
a
set
of
living
artefacts.
(Z9
can
be
downloaded
from
the
INCOSE
UK
website)
MBSE
–
is
there
any
substance
behind
the
hype?
10

11. MBSE
is
a
Philosophy
class MBSE Philosophy
Name:
Author:
Version:
Created:
Updated:
MBSE Philosophy
James Towers
1.0
03/10/2013 15:19:54
06/10/2013 15:30:55
MBSE
MBSE
is
a
kind
of
SE
SE
MBSE
defines
a
set
of
Principles,
which
shape
the
Solutions,
that
are
chosen
to
resolve
the
Problem s,
of
a
System s
Eng ineering
Project.
Systems Engineering
Proj ect
SE
is
a
kind
of
Philosophy
relates to
Context
Philosophy
1..*
0..*
1..*
1..*
defines a set of
0..*
Problem
1..*
chosen to resolve
1..*
0..*
MBSE
–
is
there
any
substance
behind
the
hype?
Solution
shapes
0..*
1..*
Principle
11

12. What
does
this
mean?
• SE
Projects
can’t
be
divided
into
“model
based”
and
“not
model
based”,
but
rather
more-­‐or-­‐less
model
based,
depending
on
their
conformance
to
the
principles
of
MBSE.
• Every
project
is
different,
and
therefore
if
you
believe
in
the
principles
of
MBSE
you
sPll
have
to
make
your
own
difficult
decisions
based
on
those
principles.
MBSE
won’t
tell
you
what
to
do.
• The
principles
of
MBSE
aren’t
complete,
they
only
augment
the
exisPng
principles
of
Systems
Engineering.
• As
a
philosophy
MBSE
has
it’s
fair
share
of
high
priests,
soothsayers
(including
cassandras)
and
zealots.
• To
successfully
implement
MBSE
within
an
organisaPon
requires
a
cultural
shir,
which
shouldn’t
be
underesPmated.
MBSE
–
is
there
any
substance
behind
the
hype?
12

13. QuesPon
2
WHAT
IS
A
MODEL?
MBSE
–
is
there
any
substance
behind
the
hype?
13

14. What
is
a
model?
•
A
model
is
“an
abstrac3on
of
reality”
such
as:
• Our
thoughts,
• This
presentaPon,
• An
Airfix
kit,
• A
requirements
catalogue,
and
• A
concept
of
operaPons
document.
– However
this
definiPon
is
too
general
to
be
of
use
here.
– Using
this
definiPon
all
SE
projects
would
be
model
based.
• which
in
some
sense
they
are!
• At
the
other
extreme
‘models’
are
somePmes
confused
with
‘diagrams’.
So
what’s
the
difference?
MBSE
–
is
there
any
substance
behind
the
hype?
14

15. Models
&
Views
bdd [Package] Model, View & Diagram [Model & View ]
Name:
Author:
Version:
Created:
Updated:
«block»
Diagram
Model & View
James Towers
1.0
09/09/2013 18:59:04
06/10/2013 16:28:29
«block»
Architecture
«block»
Matrix
1
«block»
Text Document
1..*
«block»
System
abstracts
1
«block»
Model
1..*
is a projection of
1
1..*
1
«block»
View
«block»
Table
1
Multiple representations
«block»
Graphical Symbol
1..*
0..*
«block»
Model element
1..*
represents
1
1..*
«block»
View element
«block»
Text
0..*
is related to
Single underlying definition
MBSE
–
is
there
any
substance
behind
the
hype?
«block»
Mathamatical
Language
15

16. Principles
of
a
SE
Model
• It
is
complete
and
consistent.
•
– Each
ViewElement
relates
to
1
and
only
1
ModelElement
(DefiniPon)
– You
can
use
one
view
to
validate
another.
While
it
may
be
imprecise
it
should
never
be
inaccurate.
– The
ability
to
begin
with
imprecise
(abstract)
concepts
and
refine
them
as
the
model
progresses
allows
us
to
handle
the
uncertainty
and
complexity
of
a
SE
project.
• It
is
insighvul.
– you
can
query
it
in
ways
that
you
couldn’t
query
unconnected
sources
or
even
the
most
knowledgeable
Systems
Engineer.
• This
requires
explicit
relaPonships
between
ModelElements
• It’s
harder
to
achieve
when
you
have
mulPple
repositories.
• Each
view
is
presented
using
the
most
appropriate
language,
paradigm
and
topology.
– It’s
not
just
UML/SysML
but
also
text,
maths,
rich
pictures
or
whatever
is
appropriate.
• Each
view
has
a
defined
viewpoint
(purpose).
– InformaPon
not
relevant
to
a
view
is
excluded
from
that
view.
MBSE
–
is
there
any
substance
behind
the
hype?
16

17. The
Challenge
of
MulPple
Repositories
MBSE
–
is
there
any
substance
behind
the
hype?
17

18. Appropriate
Language
• Every
language
(graphical,
mathemaPcal
or
textual)
is
built
on
a
paradigm.
– There
will
always
be
some
concepts
it
is
impossible
(or
at
least
difficult)
to
represent
using
a
given
language.
• This
problem
is
compounded
if
the
modeller
has
a
limited
experience
and/or
vocabulary
of
that
language.
– Natural
language
has
a
plethora
of
concepts
which
we
are
constantly
expanding
plus
imprecise
definiPons
which
we
frequently
overload.
• Techniques
like
EARS
(Easy
Approach
to
Requirements
Syntax)
are
designed
to
overcome
the
problems
with
natural
language.
• Languages
with
a
simple
well
defined
structure
help
us
to
manage
complexity.
– if
this
structure
is
an
inherent
property
of
the
language
rather
than
a
set
of
rules
we
apply
then
we
have
one
less
thing
to
worry
about.
• ‘Rich’
models
uPlise
the
most
appropriate
features
of
mulPple
languages.
“The
problem
with
the
French
is
that
they
don't
have
a
word
for
entrepreneur.”
–
Erroneously
credited
to
President
G
W
Bush
MBSE
–
is
there
any
substance
behind
the
hype?
18

19. Graphical
Languages
MulP-­‐
dimensional
Clear
disPncPon
of
concepts
Freedom
of
InspecPon
Immediacy
of
interrogaPon
MBSE
–
is
there
any
substance
behind
the
hype?
Easy
paYern
recogniPon
Graphical
Language
Can
be
animated
19

20. People
• It’s
not
sufficient
just
to
know
the
constructs
of
a
(modelling)
language
as
you
also
need
to
know
it’s
paYerns
and
convenPons.
– But
wherever
you
idenPfy
these
you
should
make
them
explicit.
• You
need
a
good
understanding
of
the
modelling
principles
as
for
many
of
the
problems
you
encounter
you
will
be
a
pioneer.
– Although
at
the
same
Pme
support
from
experienced
people
can
stop
you
from
reinvenPng
the
wheel.
• In
order
to
choose
the
most
appropriate
technique
you
have
to
understand
mulPple
languages,
paradigms
and
topologies.
– "I
suppose
it
is
temp3ng,
if
the
only
tool
you
have
is
a
hammer,
to
treat
everything
as
if
it
were
a
nail.”
-­‐
Abraham
H.
Maslow
(1966).
The
Psychology
of
Science
• Every
Systems
Engineer
has
to
be
a
modeller.
– If
the
model
is
to
be
‘a
single
point
of
truth’
it
needs
to
be
a
collaboraPve
effort
which
meets
the
needs
of
all
the
stakeholders.
MBSE
–
is
there
any
substance
behind
the
hype?
20

21. Processes
• Every
SE
acPvity
should
reference
the
model
and
result
in
an
iteraPon
of
the
model.
– As
it
may
not
be
immediately
clear
how
this
would
work
it
requires
a
cultural
shir
for
any
SE
organisaPon.
• The
MBSE
Principles
do
not
negate
the
need
for
an
effecPve
SE
Process.
• AddiPonal
Model
related
aspects
will
be
needed.
– As
with
all
artefacts
the
model
should
be
under
version
/
configuraPon
control.
– There
will
be
addiPonal
administraPon
effort
required,
integraPon,
security
etc.
• Where
a
more
model-­‐based
organisaPon
interfaces
with
a
less
model-­‐
based
one
there
will
be
a
need
for
translaPon
at
the
boundary.
– It’s
worth
doing
though
as
it
will
provide
a
greater
degree
of
verificaPon
for
the
inputs.
– If
any
organisaPon
is
insistent
on
the
receipt
of
text
based
specificaPons
as
input
it’s
possible
to
auto
generate
these
from
graphical
models.
• Although,
“be
careful
what
you
wish
for”.
MBSE
–
is
there
any
substance
behind
the
hype?
21

22. Tools
• MBSE
Requires
tools
with
the
right
capabiliPes.
– They
must
incorporate
the
disPncPon
between
the
model
and
mulPple
views.
– They
must
be
able
to
present
the
model
using
appropriate
languages,
paradigms
and
topologies.
• Where
mulPple
tools
are
unable
to
use
a
single
model
then:
– Some
level
of
integraPon
is
desirable.
– May
require
manual
configuraPon
control.
– You
may
need
to
make
a
trade-­‐off
between
‘single
point
of
truth’
and
‘appropriate
language’.
• You
may
be
doing
this
now
if
you
model
‘everything’
in
a
single
requirements
catalogue.
MBSE
–
is
there
any
substance
behind
the
hype?
22

23. Conclusions
• The
construcPon
of
a
model
as
a
‘single
point
of
truth’
gives
us
a
powerful
mechanism
to
mange
the
complexity
of
informaPon
and
query
such
informaPon
in
ways
that
are
not
otherwise
possible.
– We
already
see
this
to
some
extent
with
catalogues
of
requirements.
• By
uPlising
‘appropriate
languages’
we
can
use
the
inherent
structure
of
the
language
to
further
manage
complexity
and
uncertainty.
–
–
–
–
Challenges
due
to
the
limitaPons
of
a
language,
paradigm
or
topology
can
be
avoided.
No
need
to
implement
structured
frameworks
like
RQ
boilerplates.
Elements
are
always
presented
in
a
context
which
aids
comprehension.
InformaPon
may
be
hidden
when
not
relevant
through
the
use
of
views.
• ImplemenPng
such
a
strategy
is
not
easy
and
requires
commitment
on
the
part
of
the
organisaPon
plus
the
appropriate
tools,
procedures
and
skilled
individuals.
MBSE
–
is
there
any
substance
behind
the
hype?
23

24. Contact
Details
• james.towers@object-­‐flow.com
object: Flow
Helping to build better Systems
MBSE
–
is
there
any
substance
behind
the
hype?
24

25. Disclaimer
The
ideas
presented
within
this
presentaPon
are
an
evoluPon
of
the
authors
recent
submission
to
the
MBSE
working
group,
and
as
such
represents
his
personal
viewpoint
and
not
that
of
the
MBSE
working
group.
MBSE
–
is
there
any
substance
behind
the
hype?
25