Software Localization - some details in terms of how the process work - Part 8

In the previous post of this series (Software Localization - some details in terms of how the process work - Part 7), I talked about how different countries can have certain requirements that are specific to those countries, and may not be easily understood by the product team that is typically working on the English version of the product. In this post, we talk about the matrix that is typically used for determining the number of locales in which the product is to be tested.
For any software applications that has gone through multiple versions, there will be many features that are built in previous versions and are not changed in the current version. In addition, typically, when an application is tested in languages other than English, the assumption is that functionally, the application tested in the English version would work fine in terms of its features, and the need to do functional testing in other language versions should be reduced.
In a previous post, I had already mentioned that both linguistic and functional testing in other languages can be more expensive than testing in English, and hence there needs to be some optimization of the testing effort in other languages (one would like to test all the application thoroughly in different languages, but costs add a big variable to this equation and need to be considered). As a result, what typically ends up happening is that an optimization matrix is drawn where the amount of testing on each language needs to be decided upon, and this also depends on various factors, including the importance of the respective language version on the overall sales of the product.
In the next post on this subject, I will write a continuation of this topic.