Warranties | PV module manufacturers, O&M companies, owners, insurance companies and financial stakeholders employ independent engineers (IEs) to conduct plant surveys at critical milestones, such as impending plant warranty expiration (e.g. EPC warranty), or on a periodic basis. The result of the plant survey is a status report that identifies improvement potential and, in the case of specific failures or failure indicators, their corresponding root causes. Mitigating actions are mediated by the IE with all the involved stakeholders. Bill Shisler and Matthias Heinze of TUV Rheinland describe a procedure and a sample case for identifying and investigating the performance and possible safety shortcomings of PV modules, triggered by an impending asset sale.