Based on an empirical study including 3 companies, the paper addresses, problems and issues that have been encountered when introducing, and later using, Functional Products in production systems. The purpose of a Functional Product is to provide a function to customers with a specified or agreed-upon level of availability or productivity. Both operational and management-level problems and issues have been investigated. The study focuses on the customer side, involving both manufacturing and process industry companies. A set of problems and issues has been identified. The problems and issues found during the literature review have been largely corroborated, and the new problems and issues found are highlighted.