Page 86 - SOFTWARE TESTING & QUALITY ASSURANCE

Unit 6: Compatibility Testing

The ‘obsolescence concept’ emphasizes on some of the constructs that may be removed in the next
change of FORTRAN.
Some of the constructs that have been treated as obsolescent are:

1. Arithmetic IF-statement
2. Control variables in a DO-loop that are floating point or double-precision floating-point
3. Terminating several DO-loops on the same statement
4. Terminating the DO-loop in some other way than with CONTINUE or END DO
5. Alternate return
6. Jump to END IF from an outer block

7. PAUSE
8. ASSIGN, assigned GOTO, and assigned FORMAT, which relate to the whole statement number
variable concept
9. Hollerith editing in FORMAT
Information on obsolescence can be obtained from Status of FORTRAN 95, which provides details
pertaining to suggestions for the next standard, along with the new list of deleted features and the
revised list of obsolescent features.
Parallel Extensions

A group of High Performance FORTRAN Forum worked on developing the extension to Fortran 90
with parallel extensions. The intention of this project was to provide a portable language that could be
efficiently used on different parallel systems. This project was ready by May 1993, with a de facto
standard.
6.1.3 Testing Multiple Versions

To test various versions of platforms and software applications is a challenging task. We will now
consider a situation where a compatibility test is to be done on a popular operating system. The
programmers have fixed several bugs and have also improved performances by adding new features to
the existing code. There are thousands of existing programs for the present version of the operating
system. The ultimate aim of the project is to ensure 100% compatibility. Equivalence partitioning is
appropriately applied to reduce the job of testers.

The task of compatibility testing starts with the equivalence partitioning of all possible combinations of
the software. This is done to ensure that the equivalence sets verify the accuracy of the interaction
between the software. Although one can test all the possible software programs on the operating
system, only the most important ones are finalized and tested.
The criteria for finalizing the most important programs are as follows:
1. Popularity: Select the first 100 or 1000 popular programs based on sales data.
2. Age: Select programs and versions that are less than three years.
3. Type: Select software from every relevant category by segregating the applications into types like
accounting, databases, and communications.
4. Manufacturer: Select software based on the company that has created it.

The platform versions and the software applications with which the software is to be
tested must be decided before performing a compatibility testing.

Let us now learn how to test websites against multiple browsers and multiple browser versions.
Although, Internet Explorer 9 (IE9) emulates the older version of Internet Explorer (IE), the emulations
are not always accurate. This is because developers require simple, convenient ways to run multiple

LOVELY PROFESSIONAL UNIVERSITY 79