1 ECE 495 Integrated System Design I ECE 495 - INTEGRATED
SYSTEMS Requirements Specifications and Standards Timothy Burg
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ECE 495 Integrated System Design I Life Cycle of a Troubled
Project Project Initiation Wild Enthusiasm Disillusionment Change
Search for the Guilty Punishment of the Innocent Promotion of the
Nonparticipants Definition of the Requirements
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ECE 495 Integrated System Design I Design Example Mars Orbiter
Crash In 1999, NASA lost the $125 million Mars orbiter Failure was
attributed to conversion between metric and English measurement
units between contractors Lockheed Martin used English measurements
NASA navigation team used metric measurements The contractor, by
agreement, was supposed to convert its measurements to metrics
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4 ECE 495 Integrated System Design I Generic Design Process
Identify Need Research Requirements Specification Concepts Design
Prototype Testing Retire Maintain Use by Customer(s) Distribute and
Sell Manufacture Lesson: A successful project will have a technical
agreement between all parties (and they will monitor and enforce
the agreement).
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5 ECE 495 Integrated System Design I Requirements Collection of
engineering and marketing targets that a design must satisfy
Mission statement that drives all subsequent stages of development
Communication tool for everyone involved in the design;
Engineering, Marketing, Client, In some cases serves as a legal
binding contract Every important detail about what is expected is
written in this document. All parties should understand the size,
weight, reliability, electrical performance, etc. expected in the
final product.
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6 ECE 495 Integrated System Design I Design Example Gamma-Ray
Large Area Space Telescope (GLAST) Customers Vision Design Team
Harmonize the vision for the telescope through a Requirements
Document
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7 ECE 495 Integrated System Design I Design Example Gamma-Ray
Large Area Space Telescope (GLAST) http://xweb.nrl.navy.mil/glast/
Gamma-Ray Large Area Space Telescope Telescope developed by NASA in
collaboration institutions and partners in France, Germany, Italy,
Japan, Sweden, and the United States. The subsystems designed
(independently) by each group must be assembled and work together
to perform the function of GLAST Calorimeter: US, France,
Sweden
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8 ECE 495 Integrated System Design I Design Example Gamma-Ray
Large Area Space Telescope (GLAST) One important component (PIN
Diode)
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9 ECE 495 Integrated System Design I Design Example Gamma-Ray
Large Area Space Telescope (GLAST) Used Standards to describe how
routine items are done.
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10 ECE 495 Integrated System Design I Design Example Gamma-Ray
Large Area Space Telescope (GLAST) This all-sky view from GLAST
reveals bright emission in the plane of the Milky Way (center),
bright pulsars and super-massive black holes. Thousands of pages
that describe what the system should do and how well.
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11 ECE 495 Integrated System Design I Two Types of Requirements
Specifications Marketing Requirements What Customer Wants
high-quality audio fast easy to use Engineering Requirements
Technical Targets 2% distortion 100 mph 3 button interface, on-off,
volume, balance
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12 ECE 495 Integrated System Design I Marketing Requirements
Determine the voice of the customer. May require asking what the
customers wants Customer may communicate solutions with the needs.
Need to understand source of solutions and if really appropriate I
want a 1KW motor controller for may actually mean I want to control
the speed of the conveyer in . These are likely different
solutions.
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13 ECE 495 Integrated System Design I Engineering Requirements
Quantify the voice of the customer 10 grams 2% distortion 100 mph 3
button interface
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14 ECE 495 Integrated System Design I Properties of An
Engineering Requirement Abstract Specify what the system will do,
not how Unambiguous Single stated meaning with short complete
sentences Traceable Each requirement is a response to the customers
need Verifiable Can measure that the requirement is met
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15 ECE 495 Integrated System Design I Engineering Requirement
Examples Performance and Functionality Accuracy and speed
Reliability and Availability Failure rates and amount of time that
a system is available for operation Energy Energy consumption
Operating lifetime +/- 0.1 mA, 800 mm/sec Mean time between
failures (MTBF) = 30,000 hours
20 ECE 495 Integrated System Design I Engineering Standards 550
standards issuing bodies in the United States National Fire
Protection Association (NFPA) Trade association (organization
founded and funded by businesses) Publishes the National Electrical
Code (NEC) Federal Communications Commission (FCC) An independent
agency of the US government Enforces standards ANSI (American
National Standards Institute) Private non-profit organization To
aid portability between compilers defined ANSI C -> ISO C ->
Standard C ANSI paper sizes: A:8 11
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21 ECE 495 Integrated System Design I Engineering Standards 550
standards issuing bodies in the United States (cont.) The Institute
of Electrical and Electronics Engineers (IEEE) is a professional
association Professional society (EEs and CpEs) 800 standards
products Examples: 802.11, FireWire National Institute of Standards
and Technology (NIST) Government agency Atomic clock, Weights and
Measures Antenna calibrations 2012 budget $750,800,000
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22 ECE 495 Integrated System Design I Engineering Standards
Must I Follow a Certain Standard in My Design? Voluntary Standards
Adopted for the sake of ease of manufacture, interchangeability,
and safety May be used in an exclusionary way, to favor one group
or organization over its rival Mandatory Standards Standards which
are laws Failure to follow would result in legal penalty They are
generally adopted out of concern for safety
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23 ECE 495 Integrated System Design I Engineering Standards
Types of Standards Definition Standards Standards that provide
standard measurement, symbology or terminology SI or Standard
system of measurement Performance Specification Standards Doesn't
matter how a thing is made or done, but it defines a certain level
of performance Blu-Ray, USB 3.0, FireWire 800 ( IEEE 1394b-2002 )
Criteria Standards How to go about an activity, kind of the
"opposite" of a performance standard.
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24 ECE 495 Integrated System Design I Example US FCC Describes
Use of the Radio Spectrum
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25 ECE 495 Integrated System Design I Example US FCC Describes
Use of the Radio Spectrum What type of standard? Definition
Standard Performance Specification Standard Criteria Standard
Voluntary or Mandatory Standard
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26 ECE 495 Integrated System Design I Example:
IEEE-STD-299-1997 Standard Method for Measuring the Effectiveness
of Electromagnetic Shielding Enclosures What type of standard?
Definition Standard Performance Specification Standard Criteria
Standard Voluntary or Mandatory Standard Note: Cost $150 to
purchase
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27 ECE 495 Integrated System Design I Example Standard for
Specification of Requirements IEEE Standard 1233, Guide for
Developing System Requirements Specifications Properties of the
Requirements Specification (the set of all Engineering
Requirements) Normalized set Complete set Consistent Bounded
Granular (Abstractness) Modifiable
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28 ECE 495 Integrated System Design I Engineering Standards Who
Writes Standards? You and your colleagues.
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29 ECE 495 Integrated System Design I Standards and the Design
Process Identify Need Research Requirements Specification Concepts
Design Prototype Testing Retire Maintain Use by Customer(s)
Distribute and Sell Manufacture Standards give a good point to
start or at least narrow down your research Usually standards help
in describing expectations Testing- Standards should be met for all
tests conducted on product
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30 ECE 495 Integrated System Design I Example: Marketing
Requirements for a Controller for a Roller Bottle Incubator
Apparatus ? Motor and controller System that turns bottles in an
incubator. What is in the Marketing Requirements and the
Engineering Requirements? Cells Media
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31 ECE 495 Integrated System Design I Example: Marketing
Requirements for a Controller for a Roller Bottle Incubator
Apparatus The customer has asked for the following, what are the
Marketing Requirements? Wheaton Science Products seeks an apparatus
to enable you to easily scale-up anchorage-dependent cell lines
from standard plastic flasks. Benefits of the Roller Bottles are
the increased surface area, gentle agitation and improved gas
exchange when cells are rotated out of the medium. All models are
CE/UL/CSA marked for international use and are available with
different electrical plug configurations. Economy bench models
allow inexpensive entry into this technology with units rotating
from one to eight bottles. For vaccine production or when high
yield is needed, use the Wheaton Modular Cell Production Apparatus
and add decks that will hold additional bottles, as needs increase.
Backup battery systems and rotation alarms can also be added to any
Wheaton Roller Production Equipment. Wheaton Roller Apparatus
accommodates standard culture vessels, 108 to 121 mm in diameter
and up to 550 mm long.. Rotation speed can be set by the user.
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32 ECE 495 Integrated System Design I Example: Engineering
Requirements for a Controller for a Roller Bottle Incubator
Apparatus Map Marketing Requirements to Engineering Specifications
Gentle agitation -> acceleration rate rad/s/s CE/UL/CSA marked
-> testing per UL standards **** testing per CE standards ****
testing per CSA standards **** International use -> 100V-240V
input range Economy, Inexpensive -> control system
components