Introduction to Systems
Engineering
Dr Simon Li and
Part of slides are from
Qi Van Eikema Hommes
MIT OpenCourseWare
http://ocw.mit.edu
Concordia University
Lecture Outline
• Introduction to systems engineering
– Definition / examples / origins
– Profession / career aspects
– Uniqueness / power
– SE viewpoint and perspectives
• System life cycle
– Three life-cycle stages
– Evolutionary characteristics of the development
• Required reading: chapters 1, 2 and 4
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INCOSE
• The International Council on Systems Engineering (INCOSE)
is a not‐for‐profit membership organization founded to
develop and disseminate the interdisciplinary principles and
practices that enable the realization of successful systems.
• Mission: Share, promote and advance the best of systems
engineering from across the globe for the benefit of humanity
and the planet.
• Vision: The world's authority on Systems Engineering.
hmp://www.incose.org/
Definition of Systems
• A combination of interacting elements organized
to achieve one more stated purposes.
• An integrated set of elements, subsystems, or
assemblies that accomplish a defined objective.
These elements include products (hardware,
software,
firmware),
processes,
people,
information, techniques, facilities, services, and
other support element.
Source: INCOSE SE Handbook, V3.2
Characteristics of Systems
• Interaction
• Hierarchical
• Emergent
• Dynamic
• Interdisciplinary
System of Systems
Large‐scale inter‐disciplinary problems involving
multiple, heterogeneous, distributed systems.
• System components operate independently.
• System components have different life cycles.
• The initial requirements are likely to be ambiguous.
• Complexity is a major issue.
• Management can overshadow engineering.
• Fuzzy boundaries cause confusion.
• SoS engineering is never finished.
Source: INCOSE SE Handbook V3.2
What is Systems Engineering?
• Systems engineering is a discipline that concentrates on the
design and application of the whole (system) as distinct from
the parts. It involves looking at a problem in its entirety, taking
into account all the facets and all the variables and relating
the social to the technical aspect.
• Systems engineering is an iterative process of top‐down
synthesis, development, and operation of a real‐world system
that satisfies, in a near optimal manner, the full range of
requirements for the system.
INCOSE SE Handbook V3.2
Aspects
What is Systems Engineering?
• The function of systems engineering is to
guide the engineering of complex
systems.
• Guide  to lead, manage, or direct,
usually based on the superior experience
in pursuing a given course
• Engineering  design, construction and
operation of efficient and economical
structures, equipment, and systems
• Systems  a set of interrelated
components working together toward
some common objective
• Complex  diverse elements with
intricate relationships with one another
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What is “system” interested in SE?
• A set of interrelated components working
together toward some common objective
• Check your understanding
– A river system
– A transportation system
– A system of philosophy
– A system of organization and management
– A system of marking, numbering, or measuring
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Examples of engineered systems (1)
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Examples of engineered systems (2)
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Origins of Systems Engineering
• Often associated with the effects of World War II
• Driven by the development of military systems
(e.g., aircraft, radar, missiles…) under the
pressure of high performance and short
development time
• Department of Defense (US), NASA… as well as
INCOSE (professional society)
• Emerging electronics and “information age”
(computing, communication, software…)
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Three Driving Forces of SE
• Advancing technology: risks
– Robotics (electronic control), computers and IT
– Concerned with automation
– Increased risks in an unexpected way
• Competition: trade-offs
– Not the “best” system but a system of good balance of
various performance measures
• Specialization: interfaces
– Disciplinary advancements are still important
– How different parts (blocks) work together becomes
important
– “Whole” is larger than “sum of parts”
14
Profession / Career Aspects
• No “standard” recognition of systems engineers
• Career paths
– Financial, management, technical and systems
• Technical orientation
– Science: investigate the natural phenomena (physics,
electronics, chemistry, biology…)
– Math: study the logical and symbol relations (IT,
software)
– Engineering: design and develop something
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“T” model for systems engineer
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Power of Systems Engineering
• Multidisciplinary knowledge
– Provide the linkages that enable the developers of
different backgrounds to function as a team
– Intention to understand knowledge of different disciplines
– Very often, math (or IT) is the common language
• Approximate calculation
– Discover any gross omission or error quickly
• Skeptical positive thinking
– Insistence of validation of the approach selected at the
earliest possible opportunity
– Positive on the diagnosis of a failure
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Systems Engineering Viewpoint
• Involve multiple disciplines for better
performance, new innovation, lower cost
• Consider wide range of constraints for the
success of the systems
– Design for manufacturing (as well service,
operations…)
– Concurrent engineering
• Optimize multiple objectives for competition
– Not just the performance
– Meeting customer requirements
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Perspectives of Systems Engineering
Systems thinking
Systems
engineering
Engineering systems
Focus on process
Focus on whole
product
Focus on both process
and product
Solve complex
technical
problems
Solve complex
interdisciplinary
technical, social, and
management issues
Consideration of
issues
Evaluation of
multiple factors
and influences
Inclusion of
patterns
relationships, and
common
understanding
Develop and test
tangible system
solutions
Need to meet
requirements,
measure
outcomes and
solve problems
Influence policy,
processes and use
systems engineering to
develop system
solutions
Integrate human and
technical domain
dynamics and
approaches
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INCOSE VEE Model
System Life Cycle
• System life cycle: stepwise evolution of a new system
from concept through development and on to
production, operation and ultimate disposal
• No single life cycle model accepted universally and
suitable for every situation
• Some remarks
– Besides the stage “titles”, focus on the methods or tools
used in each stage
– Pay attention to how the information is connected
between stages
– Stages are often set before some important decision points
(milestones). Decisions imply cost and effort commitment.
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Example: DoD Model
• Milestone A: approve a requirements
document
– Defined with “entry” and “exit” conditions
– After approval, significant effort is committed for
engineering development
• Milestone C: approve the design
– After approval, significant cost is committed for
production
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SE Life Cycle Stages
• Conceptual development stage
– Initial stage of the formulation and definition of a
system concept perceived to best satisfy a valid need
• Engineering development stage
– Translation of the system concept into a validated
physical system design meeting the operational, cost,
and schedule requirements
• Post-development stage
– Production, deployment, operation, and support of
the system throughout its useful life
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Concept Development Stage
• Establish that there is a valid need (and market)
for a new system that is technically and
economically feasible.
• Explore potential system concepts and formulate
and validate a set of system performance
requirements.
• Select the most attractive system concept, define
its functional characteristics.
• Develop a detailed plan for the subsequent stages
of engineering, production, and operational
deployment of the system.
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Engineering Development Stage
• Develop any new technology called for by the
selected system concept, and validate its
capability to meet requirements.
• Perform the engineering development of a
prototype system satisfying the requirements of
performance, reliability, maintainability, and
safety.
• Engineer the system for economical production
and use, and demonstrate its operational
suitability.
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Post-Development Stage
• Production
– Develop tooling and manufactures system product
– Provide system to user and facilitates initial
operations
• Operation and support
– Support system operation and maintenance
– Develop and support in-service updates
27
Illustration of System Life Cycle
Operational
deficiencies
Technological
deficiencies
Flow above the blocks: the flow of information in the form of
requirements
Flow below the blocks: the step-wise evolution of the design
representations of an engineered system from concept to the
operational system.
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•
Needs analysis
– Define and validate the need for a new system
– Demonstrate its feasibility and defines system operational
requirements
•
Concept exploration
– Explore feasible concepts
– Define functional performance requirements
•
Concept definition
– Examine alternative concepts
– Select preferred concept on basis of performance, cost,
schedule, and risk
– Define system functional specifications
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•
Advanced development
– Identify areas of risk
– Reduce risks through analysis, development, and test
– Define system development specifications
•
Engineering design
– Perform preliminary and final design
– Build and test hardware and software components
•
Integration and evaluation
– Integrate components into production prototype
– Evaluate prototype system and rectifies deviations
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Evolutionary Characteristics of the
Development Process (1)
• Predecessor system
– A system is often developed based on existing systems
– Improvement on system deficiencies, or cost / risk
reduction
– Consider to what extent the existing systems can be reused
• System materialization
– The details of a system evolve “from left to right”
– Gap is possible between “early vision” to “final design”
– If “early vision” does not make good sense, it will not lead
to good “final design”
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Evolutionary Characteristics of the
Development Process (2)
• Participants
– Different developers and experts are involved at different
stages of development
– Key: provide the continuity between successive
participating levels in the hierarchy and successive
development phases and their participants through both
formal documentation and informal communications
• System requirements and specifications
– Each phase produces a more detailed description of the
system: what it does, how it works, and how it is built
– SE: oversight some documents (which also facilitate the
communication of participants)
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Table 4.1
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