Frameworks and technologies for exchanging and sharing product life cycle knowledge

Product Life cycle Knowledge (PLK) is the combination of knowledge about a product across its life time and the knowledge about all processes controlling the product life cycle. In other words, it is a kind of fusion of heterogeneous knowledge about the structure, the functions, the life cycle processes, and the operational environment having impact on the product life cycle. The origin of the term PLK is somewhat unclear. The concept of integrating and sharing heterogeneous product-internal and productexternal knowledge emerged in the late 1990s, when Product Life cycle Management (PLM) systems were conceptualized and knowledge-based engineering started to attract attention, without mentioning the concrete term itself [1–5]. The term product life cycle knowledge came into customary use gradually over the past decade. Ameri and Dutta positioned PLK as an independent research problem, ‘‘with its own contingencies and needs’’. They see PLK as content to drive PLM processes [6]. The use of the term product life cycle knowledge further has been settled on in recent work [7]. PLK stretches beyond the domains of Computer-Aided Design (CAD) data and manufacturing-related data handled by Product Data Management (PDM) in several ways. It takes a holistic approach to the product and its life cycle and, consequently, it includes heterogeneous knowledge from a variety of domains and sources encompassing various stakeholders and targeting a variety of information users. Structured and unstructured engineering information and knowledge are captured for future use at all life cycle phases [8]. This is especially true for complex products of long life cycles, such as aircrafts. Closed loops of knowledge and information interconnect all phases of life cycles to pass on ‘lessons learnt’ as feedback for developers (upstream), and to equip asset, service, maintenance and recycling engineers with product development knowledge (downstream) [6]. Thereby, PLK can be knowledge at product family or product type level, but it can also be about individual items. A life cycle-centric knowledge management approach with stakeholders-in-the-loop allows for a life-long evaluation of the instantaneous performance (utility, asset value, carbon footprint, sustainability, etc.) and the consequential decision making about the rest of the product’s useful life. Depending on its current performance and the available alternatives, this decision can be upgrade, reconfiguration, refurbishment, overhaul, remanufacturing, reuse or recycling of parts, alternatively implying continuation, elongation, or termination of the product life cycle. Existing