By transforming from a manufacturer into a PSS provider, the business model of a company changes. In particular with service-oriented business models, the importance of tangible products alters. Instead of selling products, PSS providers need product fleets that enable the provision of services. If the manufacturer of the product and the provider of the PSS fleet are identical, the products can be designed specifically for the PSS. This paper introduces a framework that supports the design of modular PSS fleets so that the product architecture is optimised for the requirements of the fleet.