Communications of the ACM

Finding and fixing bugs in deployed software is difficult and time-consuming. Here are some alternatives.

CACM Administrator

The following letter was published in the Letters to the Editor in the January 2013 CACM (http://cacm.acm.org/magazines/2013/1/158757).
--CACM Administrator

In his article "Software Needs Seatbelts and Airbags" (Sept. 2012), Emery D. Berger identified typical flaws in coding, as well as techniques that might help prevent them, addressing a major conundrum taking much of a typical programmer's time: Much more time goes for tracking bugs than for writing useful programs.

Berger's analogy of software techniques and automobile accessories was illuminating, though computer technology has generally outpaced the automobile by orders of magnitude. Some have said automobiles could go one million miles on a single gallon of fuel, reaching its destination in one second, if automobile engineers were only as bright as computer scientists. Others have said we would be driving $25 cars that get 1,000 miles to a gallon if they were only designed by computer scientists instead of by automobile engineers. But the analogy should not be stretched too far. An advocate of software reliability might say seatbelts and bumpers are not intended to protect drivers from design errors but from their own errors, or bad driving; in software the analogous problem is designer error. If defects are discovered, cars are recalled and defective parts replaced. Some software products that update themselves multiple times a day crash anyway because analogous seatbelts and airbags in software are a luxury.

The defects Berger covered are more analogous to bad plumbing and crossed wires. Moreover, software developers may not even know all the components and functions in the software they deliver. Though perfect in terms of memory handling and buffer-overflow management, software can become a work of art during development, with no way to completely anticipate how it will perform under unknown circumstances.

I would like to see researchers of software code take a look at something I call "mind of software," aiming for ways to make software more safe and predictable for common use.

Basudeb Gupta
Kolkata, India