Our company is ISO 9001:2008 certified. The question I have is how are other locations calibrating/validating tester software? We have testers that perform various tests on electronic equipment that we assemble. Currently we are using "known good" and "known bad" examples of electronic equipment to verify calibration. The software was developed and is managed at a sister facility in another state. Is it necessary for this location to conduct calibration/validation or is that a requirement of the other facility? Any help or direction would be greatly appreciated.

Think of this software as a piece of hardware, designed to test your product. You would want to be sure before putting it to use, that is would do what you want, and equally important that it didnt do what you didnt want. Who performs this verification and validation exercise isnt important so long as you have evidence of the process. In verifying your ISO9001 processes that is what your internal auditor and your registrars auditors would do. They are seeking evidence that the 'calibration' of your test software was performed with satisafctory outcomes, as required by the standard.
Hope this helps.