## 3 Results
### Synthesis: The generic Product Lifecycle Model (gPLC)  
Transferring the analytic perspective of the portfolios into a design oriented one, the results presented in Section 3.2 represent the basis of the gPLC. It is derived from the above-presented results (Figure 6). It serves as a model that has the following traits:  
* intrinsic (based on the Product Creation process from classes to instances);
* circular (emphasizing material and information circularity);
* holistic (integrating single- and multi-disciplinary and cross-cutting perspectives);
* generic (applicable to a wide variety of specific industry branches);
* adaptable (providing handles to adapt inputs, phases and flows). Product Creation is initiated by triggers, such as market pull, technology push or blue ocean strategies [106]. It is based on a company's knowledge base. In the initial step, a company brings in technology and competencies, which are available as as-iscapabilities. In that process, technology management and competency management can be connected to the gPLC in order to conceptualize the development of to-be capabilities. Five phases can be identified in manifesting the product lifecycle for multi-disciplinary product-service systems: strategic planning (linking enterprise management and product planning), engineering (subsuming systems and disciplinary engineering), realization (including production and preparation of services), operation and service delivery (from basic services like maintenance to digital business models) and decommissioning. Circularity comprises material and information. In Figure 6, material cycles are presented on the left-hand side (green arrows). Options range from reuse of products in the operation phase, repair by servicing, refurbishment/remanufacturing in assembly processes, recycling of material for manufacturing [68] (thick green arrows) and recovery for other purposes, such as energy supply (slim green arrows). On the right-hand side of the gPLC, information flows are addressed. Here, the range spans from cycles within phases (for instance, process control based on real-time data analytics) and across phases (for instance, deriving engineering guidelines from operation feedback). Information enables full cycles by learning from products for parallel and succeeding system generations and for other products in a company's product portfolio. Thus, information can be treated as one of the roots of Product Creation. Based on triggers, such as disruptive ideas, strategies, individual demands, market opportunities or technology push, the Product Creation process is initiated and begins with the strategic planning phase. Planning depends on enterprises and situations; while start-ups create their initial business models, established companies might evolve systems in terms of Product Generation Engineering [107]. Figure 7 details the multi-disciplinary perspective of the gPLC: planning can be seen as a commonality in all disciplines. For product-service systems, different viewpoints have to be merged. In engineering, processes, methods and tools vary between the disciplines. The end of this phase is marked by a design freeze. At least a Minimum Viable Product is specified, which is ready to be released to the market. Differences are obvious for the realization phase: for mechanic and electric/electronic (E/E) sub-systems, this means the step into production, including planning, ramp-up and production, depending significantly on lot sizes. Production subsumes  
Figure 6: Visualization of the generic Product Lifecycle (gPLC): Circular Economy and Product Creation as drivers; material, ideas, technologies and capabilities as inputs and roots of the cycle; multi-disciplinary products bundled with services as types and instances along joint cycles and branches. manufacturing, assembly and quality assurance. For produced parts and products, supply chain management has to be constituted, including distribution to consumers or users. For software, design freeze means that all features of the software are specified.