A system that is locked cannot process any BigFix actions. I do not recommend using locking to achieve this and instead recommend excluding such systems from most sites and targeting.
When I say a system that is “inventory only” I really mean that by some convention or mechanism you have a BigFix agent installed for inventory purposes but do not ever run actions against that system, except perhaps to upgrade the installed agent itself.
If a system is reporting in to BigFix like this, but is generally not be altered by BigFix, then the impact of analysis evaluation should be reduced since it is less critical that it be near real time since it is the more long term trend of the info that matters.
See here: What is Report MinimumAnalysisInterval? (Client Setting)