Software test engineers applying many techniques and trying hard to reduce no of test cases for any application. Though the technique reduces the test cases considerable, we are not sure coverage of the application. Common manual testing issues:
Time consuming & cost driven
More no of resources are requiredfor testing
Multiple times of testing the same set or subset of testcases in different phases
Testers do not come to a conclusion that they cover the application completely or not (ie) not sure about the coverage of the application.
There are few proven techniques available in the market; they are referred as “Pair wise testing”, combinatorial method and orthogonal arrays.
Some goals of pairwise testing are
Each value of each parameter is tested at least once
Each variable in each parameter is tested in a pair with every variable in other parameters
Pairs of variables that exist in other combinations can be dropped from the matrix of combinations
All Pairs program attempts to find the smallest number of test cases that include all pairings of each variable with each other variable. We will able to generate test cases for the interface to through out the application. We’ll generate valid input for a normal result, as well as invalid data to look at error handling.
Note: 1. Choose parameters that might reasonably interact with each other. 2. Don't mix error combination with normal combinations else led to some controversy.
Assumptions: Variables have clear equivalence classes. Variables are independent. Failures are the result of the interaction of a pair of variable values. Drawback: All Pairs can not deal with dependent input variables
Web based Pair Wise testing tool : http://allpairstesting.com/
The following steps to be used to generate test cases using weblink 1. Enter variables in Columns 2. Enter input values under each column 3. Click 'Generate' button 4. Import the data into .txt, csv and excel format for test case design
Download the ALL PAIRS tool from the following link: http://www.satisfice.com/tools.shtml
Follow the steps to prepare the combinations using ALL PAIRS tool 1. Download pairs.zip and unzip into any folder. 1. Prepare variables and inputs in excel sheet 2. copy the data from excel sheet into .txt file (change the name the way you need) 3. Run the Allpairs program from a DOS command-line like this (specify the path where allpairs.exe exists) 4. ALLPAIRS. exe <input file> > <Output file> Example ALLPAIRS VARS.TXT > TESTCASES.TXT ALLPAIRS VARS.TXT > TESTCASES.xls
Note: Here i will specify samples and how to design test cases quickly using basic excel formules for the above combinations.