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ECE 495 - INTEGRATED SYSTEMS. Requirements Specifications and Standards Timothy Burg. Life Cycle of a Troubled Project. Project Initiation . Wild Enthusiasm. Disillusionment. Search for the Guilty. Change. Punishment of the Innocent. Promotion of the Nonparticipants .

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ECE 495 - INTEGRATED SYSTEMS

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Ece 495 integrated systems

ECE 495 - INTEGRATED SYSTEMS

Requirements Specifications and Standards

Timothy Burg


Life cycle of a troubled project

Life Cycle of a Troubled Project

Project Initiation

Wild Enthusiasm

Disillusionment

Search for the Guilty

Change

Punishment of the Innocent

Promotion of the Nonparticipants

Definition of the Requirements


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

Design Example – Mars Orbiter Crash


Generic design process

Generic Design Process

Lesson:

A successful project will have a technical agreement between all parties (and they will monitor and enforce the agreement).

Identify

Need

Retire

Research

Requirements

Specification

Maintain

Use by

Customer(s)

Concepts

Distribute

and Sell

Design

Manufacture

Prototype

Testing


Requirements

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.


Design example gamma ray large area space telescope glast

Design Example – Gamma-Ray Large Area Space Telescope (GLAST)

Harmonize the vision for the telescope through a Requirements Document

Design Team

Customer’s Vision


Design example gamma ray large area space telescope glast1

Design Example – Gamma-Ray Large Area Space Telescope (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

http://xweb.nrl.navy.mil/glast/


Design example gamma ray large area space telescope glast2

Design Example – Gamma-Ray Large Area Space Telescope (GLAST)

One important component (PIN Diode)


Design example gamma ray large area space telescope glast3

Design Example – Gamma-Ray Large Area Space Telescope (GLAST)

Used Standards to describe how routine items are done.


Design example gamma ray large area space telescope glast4

Design Example – Gamma-Ray Large Area Space Telescope (GLAST)

Thousands of pages that describe what the system should do and how well.

This all-sky view from GLAST reveals bright emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes.


Two types of requirements specifications

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


Marketing requirements

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.


Engineering requirements

Engineering Requirements

  • Quantify the voice of the customer

  • 10 grams

  • 2% distortion

  • 100 mph

  • 3 button interface


Properties of an engineering requirement

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 customer’s need

  • Verifiable

    • Can measure that the requirement is met


Engineering requirement examples

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

<5W normal operation and <5mW sleep mode

> 10 hours on single charge

What is the common theme? We could measure the final system to see if it met these requirements.

I can’t make a measure to determine if something is “fast” but I could measure if it moves at 800 mm/sec


Engineering requirement examples1

Engineering Requirement Examples

  • Environmental

    • Temperature range, shock, vibration, EMI

  • Software and Computing

    • Data rates, system interface, data formats

    • Estimated learning time, menus, user error

Operate in -20oC to 100oC ambient conditions.

You are writing requirements for internet service, is this a good specification?

It is great if you are the seller, terrible for the buyer


Need a common vision for a design project

Need a Common Vision for a Design Project

What sales department

Sold to customer

What engineering designed.

How the software was written.

How it was fixed in the field during installation.

What the customer wanted

We need a common vision.

Why is this cartoon funny? Because it is so often true.


Thought exercise

Thought Exercise

  • What are the Engineering Requirements you would give to someone to have them design a peanut butter and jelly sandwich?

  • If you were describing the requirements for a picnic, it would be nice to be able to say use the “standard peanut butter and jelly sandwich”.


Engineering standards

Engineering Standards

Help you leverage the wisdom and experience of many experts to describe the system to be designed.

Document that tells how to do something or how something must behave.


Engineering standards1

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:8½ × 11


Engineering standards2

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


Engineering standards must i follow a certain standard in my design

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


Engineering standards types of standards

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.


Example us fcc describes use of the radio spectrum

Example – US FCC Describes Use of the Radio Spectrum


Example us fcc describes use of the radio spectrum1

Example – US FCC Describes Use of the Radio Spectrum

  • What type of standard?

    • Definition Standard

    • Performance Specification Standard

    • Criteria Standard

  • “Voluntary” or Mandatory Standard


Ece 495 integrated systems

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


Example standard for specification of requirements

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


Engineering standards who writes standards

Engineering Standards – Who Writes Standards?

You and your colleagues.


Standards and the design process

Standards and the Design Process

Identify

Need

Standards give a good point to start or at least narrow down your research

Retire

Research

Requirements

Specification

Maintain

Usually standards help in describing expectations

Use by

Customer(s)

Concepts

Distribute

and Sell

Design

Manufacture

Prototype

Testing

Testing- Standards should be met for all tests conducted on product


Example marketing requirements for a controller for a roller bottle incubator apparatus

Example: Marketing Requirements for a Controller for a Roller Bottle Incubator Apparatus

System that turns bottles in an incubator.

?

Motor and controller

Cells

Media

What is in the Marketing Requirements and the Engineering Requirements?


Example marketing requirements for a controller for a roller bottle incubator apparatus1

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.


Example engineering requirements for a controller for a roller bottle incubator apparatus

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 <$5, installation < 2 minutes


Example engineering requirements for a controller for a roller bottle incubator apparatus1

Example: Engineering Requirements for a Controller for a Roller Bottle Incubator Apparatus

Map Marketing Requirements to Engineering Specifications

Include a similar table in your design report.


Summary two types of requirements specifications

Summary – Two Types of Requirements Specifications

  • Marketing Requirements

    • Determine the voice of the customer.

  • Engineering Requirements

    • Quantify the voice of the customer

    • Properties of Engineering Requirements

      • Abstract (what not how)

      • Unambiguous

      • Traceable to customer need

      • Verifiable


Summary standards

Summary - Standards

  • Many Constraints on a Design

    • Standards summarize a class of constraints

    • Capture a body of experience

  • Conformance

    • Voluntary - not required by law

    • Mandatory - legal requirement

  • Contents

    • Definition - terminology

    • Performance – how well it should do some activity

    • Criteria – how to do something


Project 1 laser cutter demonstration

Project 1 – Laser Cutter Demonstration


Project 2 voltage adapter

Project 2 Voltage Adapter

A parts manufacturer has asked your team to propose an adapter design to interface between a General Performance Master Unit (Master Unit) and a General Performance Conditioning Module (Conditioning Module). The adapter will connect to a 9V supply that is accessible on the back of the Master Unit and supply 5V to the Conditioning Module. A general sketch of the desired adapter unit is shown in Figure 1. The Master Unit output voltage may be adjusted to exactly 9V (assume perfect voltage source). The Conditioning Module requires 5V ± 5%. The Conditioning Module consumes exactly 0.1W at 5V. An indicator light should be included to show that the adapter is functioning properly. The adapter must be implemented as a voltage divider with no active components. Design a device that meets the requirements above at the lowest cost (e.g. use a 10% over a 0.1% resistor if possible).


Project 2 voltage adapter1

Project 2 Voltage Adapter

  • This is a design (you don’t physically build anything)

  • Prototype is a simulation – SPICE


Website

Website

  • Your Team will use a website to build the final report

  • Hosting the Website

    • If you log onto Novell there should be a mapping U:\public.www which can then be accessed via the web as www.clemson.edu/~usernameFor example, you may create U:\public.www\index.htm and access as www.clemson.edu/~username/index.htm from a browser.

    • DO NOT USE Google or you will not be able to transfer at the end of the semester.


Individual assignment

Individual Assignment

  • Respond to article at Forbes.com "Why Amazon Can't Make A Kindle In the USA" see website for instructions.


Questions

Questions

?


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