What is Compatibility Testing?

Compatibility testing means checking how the software interacts and shares information with other software.The interaction can be between two programs on same computer , or different computers or on internet.

It can  be of two types :

1.Forward Compatibility.

2.Backward Compatibility.

1.Forward Compatibility: If something is forward compatible then it will work with future versions of the software.

2.Backward Compatibility: If something is backward compatible that means it will work with previous versions or releases.

eg. A  .txt file created in Notepad 2000 is said to be forward compatible if it works with future versions of windows such as windows 2003 etc.It is said to be backward compatible if it works with previous versions of windows such as windows 98.

It is very important to perform compatibility testing as different users have different versions of software.If the software is compatible it increases the usability of the software.

What is Configuration Testing?

It is the process of checking the software with different types of hardware.The only problem with configuration testing is large number of configuration possibilities for  the standard systems.So it can be time consuming at times and can prove costly.

How to approach Configuration testing task?

1.Decide types of hardware you need for configuration testing.

2.Decide what brands and models are available in market.

3.Identify which hardware options are possible.

4.Identify software unique feature that interacts with hardware.

5.Design and execute test cases for each configuration.

Testing Axioms

1. It is impossible to test a program completely.

It may not be possible to test a program completely because of following reasons:

- Large number of possible inputs.

- Large number of possible outputs.

- Large number of paths.

2. Not all the bugs you find will be fixed.

Several reasons because of which the bugs are not fixed are :

- Its not really a bug.

- Not enough time.

- Too risky to fix a bug.

- Its just not worth it.

3. Software testing is a risk based exercise.

One cant test everything and if you don't,you will likely miss the bug.Since the product has to be released so you need to stop testing and if you stop too soon some areas may remain untested.A huge amount of possible tests are to be reduced to a manageable set hence a risk based decision has to be performed on what to test and what not.Hence software testing is a risk based exercise.

What is Walkthrough?

Walkthroughs are semi formal types of reviews.The programmer or developer who has written the code formally presents it to a group of five or six programmers.The participants or reviewers receive the copy in advance so that they can comment or even ask questions during the review.To make a review more effective atleast one senior programmer is expected.

The presenter reads the code line by line,function by function to the participants.The reviewers raise anything that looks out to be suspicious.It is very important for a presenter to write a report after the review to tell how he will address any issues that are discovered during the review.

Walkthroughs are not as effective as inspections.

What is Inspection?

Inspections are highly effective as compared to other reviews.

Inspection is the most formal type of review.The person who presents the code is not the original programmer.The other person needs to learn and understand which gives a different interpretation.The other participants are referred to as inspectors.Every participant is expected to review the code from different perspective.

One inspector also reviews the code in backward direction.

One inspector is also asked to take task of recorder who ensures rules are followed during review process.

After inspection is done the inspectors might meet again to discuss the defects found.In some cases  when critical bugs are found re-inspection  is also done.