Please choose one topic from this weeks reading and explain its impact to your current role as an employee or student.Ethics for the Information Age, Eighth Edition, Chapter 8, Computer Reliability Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Computer Reliability Chapter 8 Eighth Edition Ethics for the Information Age If this PowerPoint presentation contains mathematical equations, you may need to check that your computer has the following installed: 1) MathType Plugin 2) Math Player (free versions available) 3) NVDA Reader (free versions available) 1 Learning Objectives (1 of 2) 8.1 Introduction 8.2 Data-entry or data-retrieval errors 8.3 Software and billing errors 8.4 Notable software system failures 8.5 Therac-25 Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Learning Objectives (2 of 2) 8.6 Tesla Version 7.0 (Autopilot) 8.7 Uber Test-vehicle accident 8.8 Computer simulations 8.9 Software engineering 8.10 Software warranties and vendor liability Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved 8.1 Introduction Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved 8.1 Introduction Computers an integral part of modern communication, transportation, retail, banking, finance, health-care systems Save time, money and enable greater productivity when working correctly Failures can result in lost time, lost money, injury, or even death Studying failures a way to appreciate complexity of building reliable computerized systems Examine increasingly important area of computer simulations High-level overview of software engineering Software warranties and issue of responsibility of software manufacturers for quality of their products Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved 8.2 Data-Entry or Data-Retrieval Errors Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Two Kinds of Data-Related Failure A computerized system may fail because wrong data entered into it A computerized system may fail because people incorrectly interpret data they retrieve Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved November 2000 general election Florida disqualified thousands of voters Reason: People mistakenly identified as felons Cause: Incorrect records entered in voter database Consequence: May have affected outcome of national presidential election Disfranchised Voters Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Sheila Jackson Stossier mistaken for Shirley Jackson Arrested and spent five days in detention Roberto Hernandez mistaken for another Roberto Hernandez Arrested twice and spent 12 days in jail Terry Dean Rogan arrested after someone stole his identity Arrested five times, three times at gun point False Arrests Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved March 2003: Justice Dept. announces F B I not responsible for accuracy of N C I C information Exempts N C I C from some provisions of Privacy Act of 1974 Should government take responsibility for data correctness? Accuracy of N C I C Records Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Impractical for F B I to be responsible for data’s accuracy Much information provided by other law enforcement and intelligence agencies Agents should be able to use discretion If provisions of Privacy Act strictly followed, much less information would be in N C I C Result: fewer arrests Dept. of Justice Position Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Number of records is increasing More erroneous records → more false arrests Accuracy of N C I C records more important than ever Position of Privacy Advocates Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Over 1 million cars stolen every year Just over half are recovered, say 500,000 Assume N C I C is responsible for at least 20% 100,000 cars recovered because of N C I C Benefit of $5,000 per car (owner gets car back; effects on national insurance rates; criminal doesn’t profit) Total value of N C I C stolen vehicle database: $500 million/year Act Utilitarian Analysis: Database of Stolen Vehicles (1 of 2) Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Only a few stories of false arrests Assume 1 false arrest per year (probably high) Assume harm caused by false arrest $55,000 (size of award to Rogan) Benefit surpasses harm by $499,945,000/year Conclusion: Good to have N C I C stolen vehicles database Act Utilitarian Analysis: Database of Stolen Vehicles (2 of 2) Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved 8.3 Software and Billing Errors Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Assume data correctly fed into computerized system System may still fail if there is an error in its programming Errors When Data Are Correct Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Qwest sent incorrect bills to cell phone customers Faulty U S D A beef price reports U.S. Postal Service returned mail addressed to Patent and Trademark Office Spelling and grammar error checkers increased errors New York City Housing authority overcharged renters About 450 California prison inmates mistakenly released Errors Leading to System Malfunctions Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Ambulance dispatch system in London Japan’s air traffic control system Los Angeles County + U S C Medical Center laboratory computer system Boeing 777 (Malaysia Airlines flight) N A S D A Q stock exchange shut down Insulin pump demo at Black Hat conference Jeep Cherokee Errors Leading to System Failures Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Amazon.com in Britain offered iPaq for £7 instead of £275 Orders flooded in Amazon.com shut down site, refused to deliver unless customers paid true price Was Amazon.com wrong to refuse to fill the orders? Analysis: E-Retailer Posts Wrong Price, Refuses to Deliver Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Imagine rule: A company must always honor the advertised price Consequences More time spent proofreading advertisements Companies would take out insurance policies Higher costs → higher prices All consumers would pay higher prices Few customers would benefit from errors Conclusion Rule has more harms than benefits Amazon.com did the right thing Rule-Utilitarian Analysis Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Buyers knew 97.5% markdown was an error They attempted to take advantage of Amazon.com’s stockholders They were not acting in “good faith” Buyers were in the wrong, not Amazon.com Kantian Analysis Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved 8.4 Notable Software System Failures Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Designed as anti-aircraft missile Used in 1991 Gulf War to intercept Scud missiles One battery failed to shoot at Scud that killed 28 soldiers Designed to operate only a few hours at a time Kept in operation > 100 hours Tiny truncation errors added up Clock error of 0.3433 seconds → tracking error of 687 meters Patriot Missile Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved (1) The radar system doing a wide area search picks up the Scud missile. (2) The radar system isolates the proposed target. (3) A software error causes the system to produce a faulty range gate. The system loses track of the missile, because it does not fly through this gate. (Figure from Science 255:1347. Copyright ©1992 by the American Association for the Advancement of Science. Reprinted with permission.) Patriot Missile Failure Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Satellite launch vehicle 40 seconds into maiden flight, rocket self-destructed $500 million of uninsured satellites lost Statement assigning floating-point value to integer raised exception Exception not caught and computer crashed Code reused from Ariane 4 Slower rocket Smaller values being manipulated Exception was impossible Ariane 5 Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Significant service disruption About half of telephone-routing switches crashed 70 million calls not put through 60,000 people lost all service A T&T lost revenue and credibility Cause Single line of code in error-recovery procedure Most switches running same software Crashes propagated through switching network A T&T Long-Distance Network Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved (1) A single switch in New York City detects an error condition and reboots. When it comes back up, it sends an “OK” message to other switches. (2) Switches in Detroit, St. Louis, and Atlanta are so busy that handling the “OK” message causes them to detect an error condition and reboot. When they come back up, they send out “OK” messages to other switches, causing some of them to fail, and so on. A T&T Long Distance Network Failure Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Mars Climate Orbiter Disintegrated in Martian atmosphere Lockheed Martin design used English units Jet Propulsion Lab design used metric units Mars Polar Lander Crashed into Martian surface Engines shut off too soon False signal from landing gear Robot Missions to Mars Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved B A E built automated baggage handling system Problems Airport designed before automated system chosen Timeline too short System complexity exceeded development team’s ability Results Added conventional baggage system 16-month delay in opening airport Cost Denver $1 million a day Denver International Airport Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved First day of trading for J-Com Mizuho Securities employee mistakenly enters order to sell 610,00 shares at 1 yen, instead of 1 share at 610,000 yen Employee overrides computer warning After sell order posted on exchange’s display board, Mizuho tries to cancel order several times; software bug causes attempts to fail Mizuho loses $225 million buying back shares Tokyo Stock Exchange Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved After problems with 2000 election, Congress passed Help America Vote Act of 2002 H A V A provided money to states to replace punch card voting systems Many states used H A V A funds to purchase direct recording electronic (D R E) voting machines Brazil and India have run national elections using D R E voting machines exclusively In November 2006 one-third of U S voters used D R E voting machines Direct-Recording Electronic Voting Machines Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved This Diebold voting machine uses a touch-sensitive screen to capture each voter’s choices. (A P photo/Rogelio Solis) Direct-Recording Electronic Voting Machine Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved Voting irregularities Failure to record votes Overcounting votes Misrecording votes Lack of a paper audit trail Vulnerability to tampering Source code a trade secret, can’t be examined Possibility of widespread fraud through malicious programming Issues with D R E Voting Machines Copyright © 2020, 2017, 2015 Pearson Education, Inc. All Rights Reserved States had second thoughts about D R E voting machines May 2007: Florida legislature voted to replace D R E voting machines with optimal