I’d like to try to help a bit - and there a LOT of different strategies on this. It really is based on your company, and the complexity of the system.
A complex system will have bugs and issues. Commissioning is the process of finding and fixing these bugs. So yes, for complex systems commissioning would show that you are not ready to qualify. At this point, qualification is pretty much guaranteed to succeed. Please be aware that commissioning could be pretty similar to qualification in scope and detail, but commissioning might look at different things too. For example you might commission an air handler (very detaiiled). But then during qualification you only qualify the differential pressure control, and maybe temperature/humidity (if your product is sensitive to temperature and humidity).
For simple systems, (like a balance/scale), I would not do any commissioning. This is an off the shelf item, and there really aren’t any issues/bugs to find and fix. I would simply go into qualification.
Also, some companies treat commissioning as a GMP activity, with deviations QA approval, change controls, etc. My personal opinion is that this defeats the purpose of commissioning which is to find and fix issues. If you’re writing deviations when you find an issue, then you hinder commissioning for both speed and cost. Having to write deviations for commissioning issues is too large an encumberance. (By the way, I will probably get people who disagree with this statement - that is why I stated that it depends on your company and the complexity of the system).
I’ve heard it said that qualification is a walk down memory lane, and not a path of discovery. I would state that commissioning is a path of discovery - treat is as such.
But to answer your question overall. Commissioning is a good activity to ensure you are ready for qualification.
What system are you asking about? What are you commissioning and qualifying? This could help the forum answer your question about what the differences are between commisioning and qualification.