Thanks:  0
Likes:  0
Dislikes:  0

# Thread: How to calculate no. of test cases from req. ?

1. ## How to calculate no. of test cases from req. ?

Hi All,

Can anybody tell me that how can we calculate number of test cases from Requirement document? Is there any particular method to know the exact number of test cases?

Thanks &amp; Regards,
Naveed

2. ## Re: How to calculate no. of test cases from req. ?

I don't think there is a method to know the exact number of test cases before writing that. It depends on the approach which you use. Some folks write functional level and some write unit level test cases. According to me test coverage matters rather than no. of test cases.

/Soori

3. ## Re: How to calculate no. of test cases from req. ?

[ QUOTE ]
It depends on the approach which you use.

[/ QUOTE ]

Does it? I can't think of any practical approach that would give me an exact number of test cases from a requirements document - we're missing several key stages.

4. ## Re: How to calculate no. of test cases from req. ?

suri is right. There isn't any method that will tell you the exact number of test cases for a requirement. However if your manager of some else is asking for the number of test cases will be made, You can checkout historical data and/or you can consult people who have already worked on the similar kind of requirement.

5. ## Re: How to calculate no. of test cases from req. ?

There isn't a way to come up with the exact number of test cases. But... based on the type of tests you will be wanting to run you could come up with an EWAG (Educated Wild A\$\$ Guess).

For example, you want to test for Positive and Negative conditions (that's 2 right there). Next you want to test for Equivalence &amp; Boundary Conditions (that is 7 tests; 3 around the ends (2x3 = 6) and 1 in the middle). You test for primary and alternate paths (based on Use Cases), and this is determined by the number of alternate paths plus the 1 or 2 primary. And so on and so on...

So you see, it is a very fluid thing. You need to determine what type of testing you will need to perform and then build out accordingly. One thing to note though is the redundancy of some tests (overlap), thus you will need to do set reduction to keep from repeating tests.

Pair Wise methods help in this respect. Good luck.

6. ## Re: How to calculate no. of test cases from req. ?

There is no straight forward method but you should always have atleast

1. one happy path test case.
2. Two boundary values(min and max)
3. Few negative test cases.

Thanks
Raj
Software testing tutorial

7. ## Re: How to calculate no. of test cases from req. ?

It absolutely depends on your approach (test case generation strategy), but you should use Pair Wise (Orthogonal Array) to reduce the number of TCs. Also, traceability matrix should be maintained and checked regularly, in order to ensure your test coverage.

8. ## Re: How to calculate no. of test cases from req. ?

The estimation can be done using the following data/method

Historical data
===============
If you have a similar application, then you can get the historical data, and find out how much your current project varies from that. Accordingly, give a rough guess.

Function points
===============
Estimate the number of function points that could be generated for your requirements.

This is done by the development team also. So, you may borrow the data from them.

Types of testing
================
Functional, security, Performance/stress, Interoperability etc...

Testing techniques
==================
BVA, EP, Decision Tables, State Transition etc.

The methods could be something like below:
1. Identify the types of testing to be done.
2. Identify which testing type is applied on whcih function point(FP).
3. Determine which testing technique is applied to test which FP (while doing this, remember what kind of testing you wanted to do on the FP)

4. For each testing technique, give a rough estimate on the number of test cases that can be generated:
FP1 - BVA - 8 test cases
FP2 - DT - 15 test cases
......
......

5. Compare this final data with the Historical data.

This is a bit time consuming task, but will give you better data.

This is an enhancement to what Jim has posted earlier.

Please remember that there is not specific formula or method for this. We can modify the above method. The above method is only to give you an idea on how to proceed with the estimation.

Regards
Ravi

9. ## Re: How to calculate no. of test cases from req. ?

[ QUOTE ]
Function points
===============
Estimate the number of function points that could be generated for your requirements.

This is done by the development team also. So, you may borrow the data from them.

[/ QUOTE ]

..borrowed the data from development team. Now what? How can you reach to a 'exact' number of test cases from function points?

10. ## Re: How to calculate no. of test cases from req. ?

Please look at the steps specified after Function points.
The details in my post are not independent...they are all interlinked and every item is used for calculating the number of test cases.

FYI, "exact number of test cases" can not be calculated using any method(s).
And in this context, I also would like to tell you that even after writing all test cases, we can never conclude "the exact number of test cases". Because, for one, the existing number of test cases are sufficient, for another they are too few, for yet another, they are more than needed.

"Exact number" of test cases is always subjective one.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•
Search Engine Optimisation provided by DragonByte SEO v2.0.36 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 7.89%
vBulletin Optimisation provided by vB Optimise v2.6.4 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging v3.2.8 (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
vBNominate (Lite) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Feedback Buttons provided by Advanced Post Thanks / Like (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Username Changing provided by Username Change (Free) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
BetaSoft Inc.
Digital Point modules: Sphinx-based search
All times are GMT -8. The time now is 04:44 AM.