Clocking Boilers/Furnaces Vs. Combustion Analysis

Hey everyone,

Recently I have been listening to a lot of podcasts and hearing alot about clocking and everything during start-ups etc. With my current company I am in residential settings therefore if need be, clocking is something I would easily be able to complete to dial in my unit on a new install or maintenance. That being said most of my work and experience is within commercial settings and as far as I have been taught and know clocking is certainly not something that can be done in most commercial settings.

So my question is,

Is combustion analysis sufficient enough when it comes to assuring an appliance is running properly and not overfiring? Of course without clocking and calculating the numbers I dont have the btu input, but hypothetically speaking is it enough?

thanks,