Supplier Production process Customer Inputs Outputs Supplier Production process Customer Inputs Outputs With service processes, the customer provides significant inputs into the production process. With manufacturing processes, groups of customers may contribute ideas to the design of the product, but individual customers' only participation is to select and/or consume the output. All managerial concerns unique to service operations are founded in this customer-input distinction . 1) Non-Service I/O Model (e.g., make-to-stock manufacturing) 2) Service I/O Model Clarifying services operations management with a unified services theory, Froehle & Sampson, POMS CHRONICLE VOLUME13 NUMBER 1 Unified Services Theory