The Fundamental Nature of Systems Engineering

1
The Fundamental Nature of Systems Engineering

• Stephen Cook and Timothy Ferris
• Systems Engineering and Evaluation Centre
• University of South Australia

2
Outline

• Introduction
• The Area of Concern for SE
• A Framework of Ideas for SE
• Methodologies Employed in Systems Engineering
• Discussion
• Conclusion

3
Introduction

• Systems Engineering has been a recognisable
  activity for around 50 years
• Started in response to the complexity encountered
  in the development and operation of large,
  socio-technical systems
• Over twenty years ago the management science and
  systems thinking communities characterised
  systems engineering along with its sister
  disciplines operations research and systems
  analysis as a most suitable for mechanical-unity
  problems. This has endured.
• This paper seeks to expose the nature of
  contemporary systems engineering

4
A Framework of a Discipline

• We have found it useful to examine SE using
  Checklands framework for a discipline F, M A.

Figure 1.
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Outline

• Introduction
• The Area of Concern for SE
• A Framework of Ideas for SE
• Methodologies Employed in Systems Engineering
• Discussion
• Conclusion

6
The Area of Concern for Systems Engineering

• An interdisciplinary approach and means to
  enable the realization of successful systems.
  (INCOSE SE Handbook current version.)
• SE usually brings up connotations of the
  production of Defence and Aerospace
• It can be much broader!
• We like Hitchins definition the art and
  science of creating systems

7
Simon Ramos Definition of SE

• Systems engineering concentrates on the design
  and applications of the whole as distinct from
  the parts looking at a problem in its entirety,
  taking into account all the facets and all the
  variables and relating the social to the
  technical. (Simon Ramo, 1973, cited in Rechtin
  1997)

8
Excerpt from INCOSE Technical Vision

• Systems engineering is a professional endeavor
  that leads to the engineering of a system of
  humans, organizations and technologies through
  knowledge management efforts associated with
  bringing the perspectives of all stakeholders to
  the associated issues to bear, such as to enable
  the appropriate definition of the system to be
  engineered such as to achieve needed capabilities
  and fulfill requirements development of the
  system through appropriate architecture, design,
  and integration efforts and ultimate deployment
  of the system in an operational environment and
  associated maintenance and reengineering of it
  throughout a useful lifetime of trustworthy
  service to these stakeholders.

9
ISO 152882002 Outlines the Scope of SE
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Hitchins Covers the Scale of SE Practice in Five
Levels
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Particular Systems Activities can be Mapped on
this Space

• Useful representation because it
• Illustrates the scope of the activities the fall
  within SE
• Illustrates how activities interact, emphasising
  the open system view
• Indicates that the 15288 processes can be applies
  at levels beyond Level 2

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Outline

• Introduction
• The Area of Concern for SE
• A Framework of Ideas for SE
• Methodologies Employed in Systems Engineering
• Discussion
• Conclusion

13
Towards a Framework of Ideas for SE

• Contributed to by
• Science and engineering as they apply to the
  system and its elements
• (Systems engineering) philosophy
• An analysis of the grounds of and concepts
  expressing fundamental beliefs (Merriam-Webster,
  2003)
• Analysis with respect to the core tenets of the
  discipline of philosophy logic, aesthetics,
  ethics, metaphysics, and epistemology
• Systems theory and practice

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Philosophy of Science vs Philosophy of
Engineering(Checkland, 1981)

• Science
• Highest value attaches to advancement of
  knowledge
• Have we learned anything?
• Extensive literature
• Engineering
• Prizes most highly the efficient accomplishment
  of some defined purpose
• Does it work?
• Scant literature

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Relationships Between Science, Technology,
Engineering Science and Engineering (Johnstone et
al, 1999)
The philosophy of science is only partially
relevant
s
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Early NASA SE Philosophy(From Hitchins, 2003)

• Systems engineering requires a clear, singular
  goal.
• There should be a sound concept of operations
  (CONOPS) from start to finish of the mission.
• There should be an overall system design that
  addresses the whole mission from start to finish.
  The full CONOPS should be demonstrably realized
  in the design.
• Overall system design can be partitioned into
  complementary interacting subsystems. Each
  subsystem should have its own clear mission and
  CONOPS.
• Each subsystem may be developed independently and
  in parallel with others provided that fit, form,
  function, and interfaces are maintained. Where
  any emerging deviations are unavoidable, whole
  system design may be revisited.
• Upon integration of the subsystems, the whole
  system should be subject to tests and trials,
  real and simulated that expose it to extremes of
  environment and to hazards such as might be
  experienced during the mission.

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Hitchins More Contemporary SE Philosophy

• The philosophy of systems engineering is
  fundamentally holistic.
• The detail of the subsystems is of secondary
  importance at system design level and that the
  subsystems need to be tuned not to optimise
  subsystem performance but rather overall system
  performance.
• Systems engineering is a problem-solving
  paradigm.
• The identification of the correct problem space
  and the selection between candidate solutions is
  performed within what he calls the systems
  engineering problem-solving paradigm that is
  fundamentally a design process.
• He proceeds to introduce systems theory and
  concepts of emergence and connectedness as the
  guiding lights of contemporary systems
  engineering practice.

18
Philosophy of SE from Philosophy of Engineering
and Systems Thinking

• The philosophy of pragmatism, particularly as
  defined by Charles Saunders Peirce and
  interpreted by Carl Hausman, provides an
  underlying philosophy to systems thinking
  (Barton).
• Logical positivism, utilitarianism, and
  existentialism each provide a useful basis for
  certain engineering activities but none is
  sufficient in itself (Johnstone et al)
• Engineers need to adopt a mosaic of philosophical
  types to achieve best results (Crawford)
• Eg, engineers informed by empiricism and
  rationalism
• And all of the above

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The Philosophy of Engineering is Embryonic

• Johnstone freely admits that their work is but a
  beginning, for they say that a philosophy of
  engineering would need to cover
• the essential ability of engineers to synthesise
  working designs with scant formal knowledge of
  the principles they are employing and incomplete
  knowledge of the technical aspects of
  implementation. (It would also need to cover the
  philosophy of value and cover ethics, aesthetics,
  etc.)

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Systems Thinking

• Conscious use of the concept of wholeness
• A system exhibits properties and behaviours that
  are greater than the sum of the parts
• Antithesis to Cartesian reductionism
• Emergence and hierarchy
• Communication and control
• Boundaries
• Openness
• The concept of system as no more than a mental
  model
• Increasingly taught in SE classes

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Outline

• Introduction
• The Area of Concern for SE
• A Framework of Ideas for SE
• Methodologies Employed in Systems Engineering
• Discussion
• Conclusion

22
Methodologies Employed in Systems Engineering

• SE considered by many to be a set of interacting
  processes that an organisation needs to perform
  to achieve a desired goal
• This ignores the creative aspects of design and
  process architecting
• SE can be considered a generic problem-solving
  methodology

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The General Problem-Solving Methodology
(Hitchins, 2005)
Figure 6.
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Hitchins SE Problem-Solving Paradigm
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Equivalent to a Design Process(Finkelstein and
Finkelstein, 1983)

• This is a dynamic, iterative process within the
  ideal solution criteria evolve along with the
  candidate solutions

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Hitchins Problem-Solving Method

• The process has the following key
  characteristics
• It addresses all the problem symptoms together,
  and therefore the whole problem or issue
• The solution is synthesized without Cartesian
  reduction to avoid the risks inherent in separate
  part solutions
• There is a verification mechanism

Figure 9.
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IEEE 1220 is Often Used At Lower Levels
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A SE Process is Applied Several Times
Conceptual Design
Preliminary Design
Detail Design Development
Production and/or Construction
Utilization and Support
Phaseout and Disposal
Need
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The Spiral Model is More Valid RepresentationReco
gnises the ongoing evolution of many systems
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SE Employs Many Disciplines

• Engineering
• Management
• Law
• And a few more

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Some Disciplines Employed Within Systems
Engineering

• Human Resource Management
• Organisational Architecting
• Requirements Engineering
• System definition and requirements analysis
• Functional analysis
• Requirements flow down and allocation
• System synthesis
• Trade studies
• Modelling and simulation
• Specification generation
• Configuration management
• Risk analysis and management
• Test and evaluation
• Reliability
• Availability
• Maintainability
• Interoperability
• Compatibility
• Logistics supportability

• Systems integration
• Safety
• Manpower supportability
• Training
• Electromagnetic compatibility
• Parts engineering
• Survivability and vulnerability
• Integration
• Contamination and corrosion
• Value engineering
• Diagnostics
• Power efficiency
• Integrity
• Capital costing
• Tempest
• Trusted systems
• Test design
• Verification and validation
• Production engineering

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Tailoring the SE Approach to Suit the Problem
Space

• Given the range of problems spaces for which SE
  can be applicable, Vencel and Cook have derived a
  set of attributes that can help the practitioner
  characterise SE sub-problems.
• Work is beginning on a tool to help practitioners
  identify approaches that match their problem.

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A Set of Problem Attributes
Table 1.
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Outline

• Introduction
• The Area of Concern for SE
• A Framework of Ideas for SE
• Methodologies Employed in Systems Engineering
• Discussion
• Conclusion

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Discussion

• SE can embrace a wide range of methodologies that
  are derived from a broad range of disciplines
• SE differentiates itself from other systems
  methodologies through
• The scale of the problems it tackles
• The duration of the activity
• Being a design methodology that can create the
  system of interest ab initio and not only shape
  it
• Being able to deal with technical aspects of the
  solution as well as social aspects
• Being able to invoke a wide range of
  methodologies to investigate sub problems

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Discussion, Continued

• SE can tackle very complex problems on the scale
  of national infrastructure and supply chains
  problems that are not simple.
• SE can and often does invoke a range of
  non-monist frameworks of ideas and techniques to
  help tackle problems of this scale.

37
Outline

• Introduction
• The Area of Concern for SE
• A Framework of Ideas for SE
• Methodologies Employed in Systems Engineering
• Discussion
• Conclusion

38
Conclusion

• Have examined SE through F, M, and A.
• We conclude that systems engineering is not well
  characterised as a simple, unitary methodology.
• SE is better thought of as a meta-methodological
  approach to creating and supporting large,
  complex socio-technical systems.

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SE is Aligned with the Paradigm Shift from
Objects and Disciplines to Relationships(Capra,
1996)
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?
41
The Effect of Discipline-Based Education (from
Kline, 1995)