# Personalised Production in the Age of Circular Additive Manufacturing
## 2 Methodology and Literature Review
### Environmentally Sustainable Personalised Production  
[PERSON] and [PERSON] [57] highlight a number of gaps in personalised production research, with the most pertinent being the lack of a repository or search system to capture designs for personalised products and co-created designs generated with customers. Not having to'reinvent the wheel' for each product could lead to lower costs and more efficient and pleasing designs for the consumer, helping them to more readily select feasible solutions. A strong argument exists that highly customised and personalised products can lead to more environmentally sustainable production, in that products meet customers' exact needs, and production models can shift away from production in anticipation of demand, leading to the increased potential of overproduction and unwanted production of goods. [PERSON] et al. [58] make the case that all stages of the product lifecycle should be considered in terms of their sustainability, this includes waste minimisation at the production stage.  
The rise of personalised production also challenges the need for large scale factories, opening up the prospect of micro production facilities. [PERSON] et al. [45] make the point that the latest manufacturing robotics and machines can be housed in small scale facilities. [PERSON] and [PERSON] [59] put forward the concept of 'Factory in a box', where the production machinery comprising a manufacturing cell is installed within a shipping container-sized space. Originally conceived as a way to bring low to medium volume high technology manufacturing to low-wage countries (via shipping containers), this concept may gain further traction with the move towards personalised production. [PERSON] et al. [60] also examine small-scale factory production methodologies through a study of 'Makespaces', which are local 'Community-based digital fabrication workshops' capable of realising designs through prototyping or a low-scale production stage, as well as acting as repair facilities. While Makespaces are best known as 'hacker' spaces, providing the incubation resources for experimental design and development of new technology, this methodology may provide impetus to personalised production, co-creation and a new methodology for R&D in this mode of production. [PERSON] et al. [60] host their work in wider distributed manufacturing movements, where larger monolith factories are broken down into smaller satellite facilities located in or near local customer bases within a national territory.  
Small (physical location and environmental) footprint production as discussed above is of particular relevance to small and medium sized (SME) manufacturers. [PERSON] and [PERSON] [61] examine mass personalisation strategies for use with such SME producers, particularly that of collaborative manufacturing networks. Introducing the concept of tradable production facilities, the prospect of horizontal integration between manufacturers is realisable at the SME level in the work of [PERSON] and [PERSON] [61].  
The achievement of sustainable production and circular economy goals through 3D printing is an active area for research. [PERSON] and [PERSON] [62] explored the use of LCA (Life Cycle Assessment) to establish if polymer-based 3D printing used in a distributed manufacturing setup would prove to involve a lower environmental impact than with conventional manufacturing. This was found to be the case in the research, with reductions in greenhouse gases and energy use resulting from the combined use of additive and distributed manufacturing approaches. [PERSON] et al. [63] also make the case for the dynamic population of LCA with data streams produced by intelligent products at different stages of their lifecycle.