Saturday, June 2, 2007

Common mistakes of Software developers


Most Software developers are not even aware that there favorites methods are problematic. Quite often experts are self thought, hence they tend to have the same bad habit as when they first began, usually because they never witnessed the better ways of performing their embedded systems. These experts then train novices who subsequently acquire the same bad habits. The purpose of this presentation is to improve the awareness to common problems, and to provide a start towards eliminating mistakes and thus creating software that is more reliable and easier to maintain.

It is easy for spending a million on testing a program. Common estimation of the cost of finding and fixing the errors in program range from 40% to 80% of total development cost. Companies don’t spend this kind of money to “verify that a program works”. They spend it because the program doesn’t work, it has bugs and they want them found. No matter what development methodology they follow, their programs still end up with bugs. Beizer’s (1990) review estimation the average number of errors in program released to testing at 1 to 3 bugs per 100 executable statements. There are big differences between programmers, but no one’s work is error-free.

One error per 100 statements is an estimate of public bugs; the ones still left in program after the programmer declares it error-free Beizer (1984) reported his private bug rate, how many mistakes he made in designing and coding a program, as 1.5 errors per executable statement. This includes all mistakes including typing errors.

“At this rate, if your programming language allows one executable statements per lines, you make 150 errors while writing a 100 lines program.”

Most programmers catch and fix more than 99% of their mistake before releasing a program for testing. Having found so many, no wonder they think they most found a lot. But they haven’t .Tester’s job is to find the remaining 1%.

Correcting just one of the mistakes within a project can lead to week or months of savings in manpower (especially during the maintenance place of a software life cycle.).

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