Engineering

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Engineering
of
Systems
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Systems Engineering

• An Introduction

M R Shankar
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Outline

• What is SE?
• Why SE?
• Where it can be?
• How SE?(A big question)
• A Generic SE process

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What is a System?
Electrical
Avionics
Hydraulics
Mechanical
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What is a System?

• A group of components that work together for a
  specified purpose
• Components - products (hardware, software,
  firmware), processes, people, information,
  techniques, facilities, services and other
  support elements
• Together integration of many
• Purpose is achieved by implementing many
  functions

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Other
Systems
Natural
Man made
Technical
Non Technical
Aircraft Missile
Economic system Societal systems
Emphasis on Technical systems
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Technical Systems

• Human-made artifacts
• Result of engineering activities with the
  processes of engineering design
• Difficult to classify systems based on technology
  like electrical system, mechanical system
• Most present day systems are hybrids of simple
  systems of the past
• An indication of the need to use
  inter-disciplinary approach

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What is Engineering?

• Knowledge of mathematical and natural sciences
  applied to utilize limited resources economically
  for the benefit of people
• Scientific approach
• Optimize resources
• User/customer in focus

Classical Engineering focused mainly on product
design
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Systems Engineering (SE)

• SE is an interdisciplinary approach and means to
  enable realization of successful systems
• It is very quantitative including tradeoff,
  optimization, selection and integration of
  products from various engineering disciplines
• It is more of an engineering discipline.

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Why SE is needed
Complexity
Project
Technical
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Wright Brothers
Why SE?
Designed, Built and Flew the worlds first
powered, controlled, heavier-than-air flight
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Why SE?
ONE Chief Designer TOTAL knowledge
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• High Complexity
• Multidisciplinary
• Cost Time

SE is needed due to Technical complexity
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Why SE?

Commitment to technology, configuration, cost etc
100
75
Cost incurred
System specific knowledge
50
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Ease of change
Detail design development
Concept prelim. design
Production
Use, phase-out disposal
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Why SE (cont..)

• More systematic way of development
• Better control of System Development incl.
  management of risk, changes, configuration
• Traceability at all levels
• Operational supportability aspects
• Effectiveness Analysis
• Risk management
• Operational - Maintainability, Availability,
  Safety etc

Ensures FINAL PRODUCT Fully Meets All User
Requirements
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Where SE?

• All levels
• Organization level for a project
• Full fledged SE
• Subsystem level
• We aim at this level!!
• Individual level
• Systems thinking

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Systems Engineering (SE)

• Emphasis on
• Top-down approach
• Interdisciplinary approach
• Effort on more complete definition of system
  requirements
• Life cycle engineering approach

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Emphasis in SE

• Top-down approach
• Look at system from top
• Decide inputs/outputs taking into account the
  supersystem
• Decide subsystems
• down to lower levels
• Interdisciplinary approach
• Analytical approach is inadequate
• Capture the interactions between disciplines
• Exploit the synergism of these interactions

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Emphasis in SE

• More complete definition of needs
• Complete definition of needs facilitates
  verification of system performance
• Minimize surprises at later stages
• Life cycle engineering approach
• Initial approach was Design cycle
• Later with Design for Manufacture (DFM) approach
  Manufacturing cycle also included
• Present thinking is to consider three life cycles
  i.e. Design, Manufacturing and Supportability
  concurrently
• Leading to Concurrent Engineering (CE)

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• Life-cycle engineering approach

Utilization phase
Development phase
Design
Manufacture
Deployment
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Product life cycle
Identification of need
Research Input
Conceptual design
System concept
Preliminary Design
Subsystem design
Detailed Design Development
Component design
Production/Construction
Development phasing
Utilization Support
Phase-out and Disposal
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Systems Engineering process

• Basic steps
• Define system objectives (users needs)
• Establish performance requirements (requirements
  analysis)
• Establish functionality (functional analysis)
• Evolve design and operation concepts (design
  synthesis)
• Select a baseline (thro trade-off studies)
• Verify the baseline meets requirements
• Iterate the process through lower level trades
  (decomposition)

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Requirements analysis
Functional analysis
INPUT
R
D
V
Design Synthesis
System Analysis Control
OUTPUT
Concept studies
System studies
Prelim. Design
Detailed Design
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• Conceptual design
• Preliminary design
• Detailed design Development

• Requirement analysis
• Functional analysis
• Design Synthesis
• System analysis and control

Development phasing

• Development
• Production
• Deployment
• Operation
• Support
• Training
• Verification
• Disposal

System Engineering process
Life cycle approach
This interaction shows how to apply SE process to
develop systems in life cycle approach
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Aids to SE Management

• Functional baseline
• Allocated baseline (Design to specs.)
• Product baseline (Build to specs.)

Drawing inputs from all the life cycle activities
for various development phases
Development phasing
System Engineering Management
System Engineering process
Life cycle approach
Integrated team from Systems engineering and
discipline specialists
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SE process overview
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SE process mapped to Life cycle
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What we have seen

• What is a System
• What is Systems Engineering
• Why Systems Engineering is needed?
• Life cycle engineering approach leading to
  Concurrent Engineering
• Product cycle development phasing
• Steps in System engineering process

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I will stop here

• We will move forward

Ref INCOSE SE handbook DSMC SE mgmt
guide Systems Engineering Analysis
Blanchard Fabrycky
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Baselines

• Functional baseline
• Top level (system) functions, performance
  interfaces.
• System level technical description
• Allocated baseline
• System requirements flowed down to items below
• Item performance specification, interface
  definitions, process description and drawings
• Design to specifications
• Product baseline
• Defining system from top to bottom in terms of
  physical entities
• Build to specifications

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System classification

• Natural manmade systems
• River system, Bridges
• Physical conceptual systems
• Airline system, economic system
• Open closed systems
• Chemical equilibrium in closed vessel, business
  organization
• Static Dynamic systems
• Bridge, Aircraft

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What is a system?

• A group of components that work together for a
  specified purpose e.g. Aircraft
• Purpose is achieved by implementing many
  functions
• System is made up of components, attributes and
  relationships
• Components are the operating parts consisting of
  input, process and output e.g. Wing
• Components may be structural, flow or operating
• Attributes are the properties that characterize
  the system e.g. Lift generated
• Relationships are links between components and
  attributes
• The purposeful action by system is its function.