1 On the Various Conceptualizations of Systems …and Their Impact on the Practice of Systems Engineering 2008 INCOSE Symposium James N Martin Timothy L J Ferris © 2008 The Aerospace Corporation & Timothy L J Ferris

2 Systems Thinking A system is a way of looking at the world. … a system, any system, is the point of view of one or several observers. A system is a way of looking at the world. … a system, any system, is the point of view of one or several observers. Gerald M. Weinberg (1975), An Introduction to General Systems Thinking

3 Thing System as a Point of View Point of View Image Observer

4 Two Observers Two Systems Thing Observers Point of View Image

5 Some Recent History The Solar System (2005) The Sun plus 9 Planets The Solar System (2006) The Sun plus 8 Planets

6 Our Choice… The things we put into our System –Are things of our own Choosing –Are there for the purpose of Understanding –Are not pre-determined by some magical Rules of Inclusion We must choose Carefully –A wrong choice could lead to incorrect Understanding –We often dont know a priori what is the best Rule of Inclusion to use –May need to experiment with different possible System boundaries & configurations

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13 A Common (Mis)Perception System = Sum of Parts That We Design & Build

14 System Parts

15 Parts – Also Known As… Subsystems Elements Products Devices Subassemblies Components Items Units

16 What are the Parts of this System ? Camera Lens Assembly Flash Device Electronic Circuit User Interface Unit Carrying Case Shipping Container Instructions Technique for Holding Extra batteries Photo Printer Patents

17 We need to Imagine more than just the things we build…

18 What Types of Parts Constitute a System? Hardware and Software ?? Hardware and Software and People ??

19 Types of System Parts PATENT BASIC PART TYPES HARDWARESOFTWAREPERSONNELFACILITIES DATAMATERIALSSERVICESTECHNIQUES

20 More Than Just Parts… System = Sum of Parts + Interactions

21 How many ways to Interact ?

22 Which is the best way to Interact ? ?

23 Beyond Interactions… System = Sum of Parts + Interactions + Context

24 Context 1 PART Context 2 PART

25 Beyond Context… System = Sum of Parts + Interactions + Context + Actions

26 Camera Actions

27 Action Diagrams

28 Context A Action in Different Contexts Action 1 Action 2 Context B Action 1 Action 3

29 Beyond Actions… System = Sum of Parts + Interactions + Context + Actions + Relationships

30 Relationship Types Interpersonal –Family, Friends, Social, Organizational, … Mathematical –Equality, Order, Topological, Functionality, … Cause-Effect –Event-Driven, Probabilistic, … Physical Properties –Forces, Fields, Chemical effects, …

31 Entity-Relationship Pairs Entity A Entity B Related to Rain Wet Ground Causes

32 Relationship Examples Balls Box Inside Road Building Brings traffic to and from

33 Observing System Relationships Observing System Data Handling System provides data to User provides info to

34 Observing System Relationships Observing System Data Handling System provides data to User provides info to is type of Stake- holder has Stakeholder Requirement

35 Observing System Relationships Observing System Data Handling System Environmental Phenomenon provides data to Basic Service Requirement < drives User provides info to is type of Stake- holder has Stakeholder Requirement < drives

36 Observing System Relationships Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor measures is a contains characterizes provides data to Basic Service Requirement < drives User provides info to is type of Stake- holder has Stakeholder Requirement < drives

37 Observing System Relationships Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station measures is a contains characterizes provides data to Location located at MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has situated on Stakeholder Requirement < drives

38 Observing System Relationships Larger System Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station part of measures is a contains characterizes provides data to Observation Control System is controlled by Location located at MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has Operator operated by situated on Support supported by Owner owned by Stakeholder Requirement < drives

39 Observing System Relationships Larger System Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station part of measures is a contains characterizes provides data to Observation Control System is controlled by Location located at MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has Operator operated by situated on Support supported by Owner owned by Stakeholder Requirement < drives

40 System = Sum of Parts + Interactions + Context + Actions + Relationships + Destiny And Finally…

41 Destiny Impact Purpose

42 PICARD Theory of Systems P arts I nteractions C ontext A ctions R elationships D estiny Holistic Image of System = From the Point of View of an Observer

43 Thing Systems are Imaginary Point of View Observer Image

44 System – Seen by Operator Larger System Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station part of measures is a contains characterizes provides data to Observation Control System is controlled by Location MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has Operator operated by situated on Support supported by Owner owned by Stakeholder Requirement < drives

45 System – Seen by User Larger System Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station part of measures is a contains characterizes provides data to Observation Control System is controlled by Location MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has Operator operated by situated on Support supported by Owner owned by Stakeholder Requirement < drives

46 System – Seen by Developer Larger System Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station part of measures is a contains characterizes provides data to Observation Control System is controlled by Location MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has Operator operated by situated on Support supported by Owner owned by Stakeholder Requirement < drives IF

47 System – Seen by GEOSS Larger System Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station part of measures is a contains characterizes provides data to Observation Control System is controlled by Location MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has Operator operated by situated on Support supported by Owner owned by Stakeholder Requirement < drives

48 System – Seen by NOAA Director Larger System Observing System Data Handling System Human Environmental Phenomenon Environmental Parameter Sensing Element Sensor Platform / Station part of measures is a contains characterizes provides data to Observation Control System is controlled by Location MobileFixed is Space Air Ground Ocean Space Air Ground Ocean Basic Service Requirement < drives provides data directly to User provides info to is type of Stake- holder has Operator operated by situated on Support supported by Owner owned by Stakeholder Requirement < drives

49 Systems Thinking A system is a way of looking at the world. … a system, any system, is the point of view of one or several observers. A system is a way of looking at the world. … a system, any system, is the point of view of one or several observers. Gerald M. Weinberg (1975), An Introduction to General Systems Thinking

50 Postscript All models are wrong, some are useful –George Box All systems are imaginary, some are useful –James Martin Models can be used to facilitate the imagination