Takes place when a system has to be enhanced in some way e.g. program run faster.

Description

Testing of software outside the development organisation and usually at the client site.

Takes place when a program’s environment changes, for example a different operating system.

A detailed sequence of steps which, when followed, will accomplish a task.

Testing of software within the development organisation.

Testing of software outside the development organisation using clients or selected members of the public.

A method of program refinement that starts with individual modules and builds them up into a complete program.

Running a program with test data that represents the extreme upper and lower values. Within this range the program should operate normally.

A bug is a program error.