XRAY - writing and managing tests while having reuirements on 3 levels

[MM]

Hi,

I'm new in Xray and I need to understand some things.

I have requirements on three levels. First level describe general funcionality, second is more detailed. Sometimes second level is too general so it is created third level to make it simplest as it can be.

So I write tests for the lowest level. This tests cover lowest requirements.

1. So if all lowest requirements are covered then the higher requirements are also covered, am I right?

I also have several modules that cooperate with some devices. First I write test cases on third level where I simulate data from devices, because I do not have this devices. This tests cover reuirements. Now I should write tests for situation when I have devices connected.

2. Should I create new tests linked to previous requirements? If I link them to the same requirements I can not add this tests to the same plan test as the test that I created for situation without devices. I should create next test plan for testing with connected devices, but not all of modules have external devices connected to them. To that modules I have requirements and tests. If I create test plan containing only tests cases for modules which need devices not all of the requirements will be covered (the requirements for modules that do not need devices). How should it be organized?