Cmpe 131 | Engineering homework help

1. The next article appeared within the Washington Publish (Related Press 1996): 




Dallas,, Aug. 23-The captain of an American Airways jet that crashed in Colombia final December entered an incorrect one-letter compute r command that despatched the aircraft right into a mountain, the airline stated at this time. 

The crash killed all however 4 of the 163 individuals aboard. American's investigators concluded that the captain of the Boeing 757 apparently thought he had entered the coordinates for the supposed vacation spot, Cali. 

However on most South American aeronautical charts, the one-letter code for Cali is similar because the one for Bogota, 132 miles in the wrong way. 

The coordinates for Bogota directed the aircraft towards the mountain, in keeping with a let-ter by Cecil Ewell, American's chief pilot and vp for flight The codes for Bogota and Cali are totally different in most pc databases, Ewell stated.


American spokesman John Hotard confirmed that Ewell's letter, first reported within the Dallas Morning Information, is being delivered this week to all the airline's pilots to warn them of the coding drawback. 

American's discovery additionally prompted the Federal Aviation Administration to concern a bul-letin to all airways, waroiing them of inconsistencies between some pc databases and aeronautical charts, the newspaper stated. 

The pc error shouldn't be the ultimate phrase on what induced the crash. The Colombian gov-ernment is investigating and is predicted to launch its findings by October. 

Pat Cariseo, spokesman for the Nationwide Transportation Security Board, stated Colombian investigators are also inspecting elements similar to flight crew coaching and air visitors management. 

The pc mistake was discovered by investigators for American after they compa17ed information from the jet's navigation pc with info from the wreckage, Ewell stated. 

The information confirmed the error went undetected for 66 seconds whereas the crew scrambled to comply with an air visitors controller's orders to take a extra direct strategy to the Cali airport. 

Three minutes later, whereas the aircraft nonetheless was descending and the crew attempting to determine why the aircraft had tumed, it crashed. 

Ewell stated the crash offered two essential classes for pilots. 

"To begin with,irrespective of what number of instances you go to South America or every other place-the Rocky Mountains-you can by no means, by no means, by no means assume something," he advised the newspaper. Second, he stated, pilots should perceive they cannot let automation take over accountability for flying the airplane. 

Is this text proof that we have now a software program disaster? How is aviation higher off due to software program engineering? What points needs to be addressed throughout software program improvement in order that issues like this can be prevented sooner or later?


2. Give an instance of drawback evaluation the place the issue parts are comparatively easy, however the problem in fixing the issue lies within the interconnections amongst sub-problem parts. 

three. Clarify the distinction between errors, faults, and failures. Give an instance of an error that results in a fault within the necessities; the design; the code. Give an instance of a fault within the necessities that results in a failure; a fault within the design that results in a failure; a fault within the take a look at information that results in a failure. 

four. Why can a depend of faults be a deceptive measure of product high quality? 

5. Many builders equate technical high quality with total product high quality. Give an instance of a product with excessive technical high quality that isn't thought of top quality by the client. Are there moral points concerned in narrowing the view of high quality to think about solely technical high quality? Use the Therac-25 instance as an example your level. 

6. Many organizations purchase industrial software program, pondering it's cheaper than growing and sustaining software program in-house. Describe the professionals and cons of utilizing COTS software program. For instance, what occurs if the COTS merchandise are not supported by their vend.ors? What should the client, consumer, and developer anticipate when designing a product that 

makes use of COTS software program in a big system?