In progress inspections will vary depending upon the type and scope of work at hand.
For example, in the case of a water claim (dishwasher flood the enitre house causing full remediation requirements), this could mean an inspection during the mediation work to ensure proper devices and processes are being used or it could mean an inprocess inspection at the completion of the mediation (middle of full job) to ensure all has been done in full compliance.
It could also be the same as what is commonly referred to as a felt inspection when dealing with roof replacements. These inspections help to ensure that all has been accomplished to that point in full compliance and that the proper materials to complete the job in accordance with the contract, insurance, and code, are on site.
In progress inspections are designed to designate a point in the job that should have an evaluation of completion and compliance that is likely to not be available for observation after further work has been completed.