Case study of the Patriot Missile system
| Topic area |
Safety Critical Systems |
| Target audience |
Undergrad IS/CS/CE/EE majors in general. |
| Activity type |
News articles, Reading Assignment, Worksheet, Class discussion, Role Playing |
| Time required |
This activity should be expected to take a full 50 minute class, with a possible second
50 minute class, if the ethical issues involved in the data handling aspect are discussed
separately. (See Worksheet #2) |
| Attachments |
Worksheet 1
Worksheet 2
Worksheet 3 |
| Additional materials |
Students should be given a copy of the materials listed, or have access to them:
- Activities of the House Committee on Governmental Operations (HANDOUTS)
http://www.stimson.org/rd-table/patriot.htm
- Real-Time Operating Systems: The Patriot Missile System Failure (ATTACHED)
http://church.dcss.mcmaster.ca/~cs1md3/news/news-patriot.html
- Patriot Missile Failure (HANDOUTS)
http://www.math.psu.edu/cao/disasters.html
- Fatal Error: How Patriot Overlooked a Scud (HANDOUTS), NEWS & COMMENT, 13 March 1992, p.1347.
|
| Background needed to complete the assignment |
A copy of the articles referenced above. |
| References |
- RISKS (http://catless.ncl.ac.uk/Risks.data/search.html)
- Articles referenced above.
- To order GAO report GAO/IMTEC-92-26, Call (202)-512-6000.
- Raytheon’s response to WGBH Frontline (http://pbs.org/wgbh/pages/frontline/gulf/weapons/raytheontext.html)
- Summary of Patriot Defense system (http://www.redstone.army.mil/history/netstorm/chapter3.html)
- Subsequent testing report (http://www.defenselink.mil/cgi-bin/dlprint)
|
| Last modified |
August 1998 |
Abstract:
The purpose of this assignment is to interpret and analyze the need for extremely reliable
(faultless) software in life-critical situations, using the MIM-104 Patriot Tactical Air Defense
Missile System with its computer-controlled real-time operating system as an example. Study
materials are used to emphasize terminology, software testing & debugging concerns, and related
ethical issues.
The case is of particular interest because of the high success rate initially attributed to the
patriot missiles during the Gulf War, the subsequent "Activities of the House Committee on
Government Operations", and the role of the program’s prime contractor, the Raytheon Company. An
additional factor is the failure to intercept an Iraqi Scud missile, resulting in the death of 28
soldiers at the American Army barrack in Saudi Arabia.
Goals for the activity:
There are four goals for this activity.
- Develop an understanding of the computer terms related to the problem and the programming
flaws responsible for the failure of the system.
- Learn to evaluate the software bugs and how to propose steps that might have been taken to
prevent failure and ensure reliable software.
- Develop skill in focusing on the inadequacies of reports, in this case the initial reports
of patriot success, and highlight applicable ethical issues in the reporting.
- Learn to present possible alternative behaviors that would produce more ethically
acceptable reporting and evaluation.
Knowledge / skills / attitudes to be developed (behavioral objectives):
Students are expected to develop:
- Knowledge of the consequences of using faulty software in critical situations.
- Attitudes that reflect an ability to handle data honestly.
- Skill in applying ethical guidelines to the use of software in life-critical situations as
well as to the resulting ethical dilemmas.
Procedure:
In preparation,
- Provide students with the reading materials, giving them the opportunity to read these in
preparation for the next class period.
- Distribute Worksheet #1 as a homework assignment, along with the reading materials.
During the class session,
- Collect the worksheet at the beginning of the hour.
- Involve the class in a discussion of the following topics:
- Examples of real-time software buts that can cause life-threatening problems, e.g.,
timing problems, rounding errors, cumultive errors, etc.
- Consequences of faulty & inaccurate interpretation of data (including
ethical/unethical decisions that might be made along the way).
- Ethical implications of propaganda (wartime, peacetime).
During second class session,
Carry out a role-playing scenario, similar to the House Activities Committee hearing. Have students
assume role of the Army officials, representatives from Raytheon Company, etc. Assign a student the
role of House leader (moderator), and in a mock session, try to pin-point with the students some of
the ethical issues involved in each of the roles and the responsibilities associated with those
roles. Have students summarize the results of the "hearing" on their Worksheet #2.
As homework, following the second class session,
Assign Worksheet #3 as a critical thinking/writing exercise.
Assessing outcomes:
- Grade the responses on Worksheet #1. These responses are based directly on the written
materials.
- Worksheet #2 should be completed in class as part of group activities, and hence receive
merely a complete/incomplete evaluation.
- Worksheet #3 is a writing exercise, allowing the student to express views on the use of
software in life-critical circumstances. The student should be evaluated on critical
thinking demonstrated in the response to question 1, and given the opportunity to
summarize his/her understanding of the ACM ethical guidelines in question 2.
Additional remarks:
None.
Author contact information:
Kathryn M. Baalman
Math/Computer Science
Webster University, St. Louis, MO
E-mail: kbaalman@earthlink.net
Page maintained by: kwb@csee.usf.edu