INCOSE UK: MBSE - is there any substance behind the hype?


Published on

MBSE Presentation to the INCOSE UK Railway Interest Group

Published in: Technology, Business
1 Like
  • Be the first to comment

No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide

INCOSE UK: MBSE - is there any substance behind the hype?

  1. 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. 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. 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. 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. 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. 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. 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. 8. ParPcipaPng  OrganisaPons   object: Flow Helping to build better Systems MBSE  –  is  there  any  substance  behind  the  hype?   8  
  9. 9. QuesPon  1   WHAT  IS  MBSE?   MBSE  –  is  there  any  substance  behind  the  hype?   9  
  10. 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. 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. 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. 13. QuesPon  2   WHAT  IS  A  MODEL?   MBSE  –  is  there  any  substance  behind  the  hype?   13  
  14. 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. 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. 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. 17. The  Challenge  of  MulPple  Repositories   MBSE  –  is  there  any  substance  behind  the  hype?   17  
  18. 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. 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. 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. 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. 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. 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. 24. Contact  Details   •  james.towers@object-­‐   object: Flow Helping to build better Systems MBSE  –  is  there  any  substance  behind  the  hype?   24  
  25. 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