Directives to support the design of changeable (I)PSS

Product service models (PSM) benefits are not limited to its providers and costumers, but the whole society might also take advantage from its sustainability impact. Achieving these benefits, though, require changeable product service systems ((I)PSS). Changeability means the (I)PSS' modules have built in robustness against small use variations, adaptability to use changes, and flexibility to further updating and upgrading. In order to face this design challenge and support early modular design decisions, this paper defines a set of design directives based on the here proposed AEIOU variables (Acceptance, Ephemerality, Importance, Operational, and Urgency). This paper's second contribution is a modification from the Value Function Deployment (VFD) technique. While the original VFD is a Lean Product Design and Development (LPDD) technique that supports decision making until releasing the design to production, the adaptation, which includes the AEIOU variables, extends this capability to the whole (I)PSS lifecycle. To illustrate and show the viability of the work, a fictional product development case and related design decision scenarios are discussed.