Your construction contract should have performance milestones listed for the production process.  This is the form you use to walk the project with the Client at each milestone.  The purpose of the form is two-fold.  First, you want to catch any problems while they can still be easily repaired.  Second, you want to establish that the project meets with the approval of the Client to that milestone. Comments or changes made by the client are noted in the form and can be corrected during the walk through or may generate a Specification Change document.