Transcript Systems Engineering - CASDE

Engineering of Systems
Systems
Engineering
An Introduction
M R Shankar
Outline
What is “SE”?
 Why “SE”?
 Where it can be?
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How “SE”?(A big question)
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A Generic SE process
What is a ‘System’?
What is a ‘System’?
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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
Other
Systems
Natural
Man made
Technical
Aircraft
Missile
…
Non – Technical
Economic system
Societal systems
…
Emphasis on Technical systems
Technical Systems
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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
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An indication of the need to use interdisciplinary approach
What is “Engineering”?
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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
Systems Engineering (SE)
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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.
Why “SE” is needed
Complexity
Technical
Project
Why “SE”?
Wright Brothers
Designed, Built and Flew the world’s first
powered, controlled, heavier-than-air flight
Why “SE”?
ONE Chief Designer – TOTAL knowledge
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High
Complexity
Multidisciplinary
Cost & Time
“SE” is needed due to Technical complexity
Why “SE”?
%
100
Commitment to technology,
configuration, cost etc
75
Cost incurred
System specific knowledge
50
25
Ease of change
Detail design &
Concept &
prelim. design development
Production
Use, phase-out
disposal
Why SE (cont..)
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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
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Ensures FINAL PRODUCT Fully Meets All User
Requirements
Where “SE”?
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All levels
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Organization level – for a project
• Full fledged SE
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Subsystem level
• We aim at this level!!
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Individual level
• Systems thinking
Systems Engineering (SE)
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Emphasis on
• Top-down approach
• Interdisciplinary approach
• Effort on more complete definition of
system requirements
• Life cycle engineering approach
Emphasis in SE
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Top-down approach
• Look at system from top
• Decide inputs/outputs taking into account the
supersystem
• Decide subsystems
… down to lower levels
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Interdisciplinary approach
• Analytical approach is inadequate
• Capture the interactions between disciplines
• Exploit the synergism of these interactions
Emphasis in SE
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More complete definition of needs
• Complete definition of needs facilitates verification
of system performance
• Minimize surprises at later stages
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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)
Life-cycle engineering approach
Utilization phase
Design
NEED
Development phase
Manufacture
Deployment
Conceptual &
Preliminary
Design
Detail Design
&
Development
Manufacturing
Configuration
Design
Production
and/or
Construction
Product use
Phase out and
Disposal
Manufacturing
Operations
Product support
configuration design
and development
Product support
and maintenance
Product life cycle
Identification of need
Research Input
Conceptual design
System concept
Preliminary Design
Subsystem design
Detailed Design & Development
Component design
Production/Construction
Utilization & Support
Phase-out and Disposal
Development phasing
Systems Engineering process
Basic steps
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Define system objectives (user’s 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)
INPUT
Requirements
analysis
R
V
Functional
analysis
D
Design
Synthesis
System Analysis &
Control
OUTPUT
Concept studies
System studies
Prelim. Design
Detailed Design
Requirement
analysis
Functional analysis
Design Synthesis
System analysis
and control
System
Engineering
process
Conceptual design
Preliminary design
Detailed design &
Development
Development
phasing
System
Engineering
Management
Life cycle
approach
Development
Production
Deployment
Operation
Support
Training
Verification
Disposal
This interaction shows how to apply SE process to
develop systems in life cycle approach
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
Baselines
System
Engineering
process
System
Engineering
Management
Integrated
approach
Lifecycle
planning
Life cycle
approach
Integrated team from
Systems engineering
and discipline
specialists
SE process overview
SE process mapped to Life cycle
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
Baselines
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Functional baseline :
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Allocated baseline :
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Top level (system) functions, performance & interfaces.
System level technical description
System requirements flowed down to items below
Item performance specification, interface definitions,
process description and drawings
‘Design to’ specifications
Product baseline :
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Defining system from top to bottom in terms of physical
entities
‘Build to’ specifications
System classification
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Natural & manmade systems
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Physical & conceptual systems
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Airline system, economic system
Open & closed systems
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River system, Bridges
Chemical equilibrium in closed vessel,
business organization
Static & Dynamic systems
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Bridge, Aircraft
What is a system?
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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.