From my experience in the fruit and vegetable industry most packers and processors will implement an ATP verification program only if their 3rd-party food safety audit requires it.
And a number of NPE clients decide to not use ATP as a sanitation verification tool even if their audit requires it.
Audits aside ATP testing is a very good tool to verify that your sanitation program is adequate or learn that it is not adequate.
ATP testing has the advantage of being a rapid test and it is recommended and feasible to have passing ATP results as part of a pre-op inspection.
However, ATP does not take the place of a comprehensive microbiological monitoring program that should also include equipment and facility/environmental microbiological sampling and testing.
If you have any questions about using ATP as a sanitation verification program or need assistance implementing an ATP program contact Philip Neary at NPE Produce Consulting, firstname.lastname@example.org.