# The Human Performance Impact on OEE in the Adoption of New Production Technologies
## 2 Literature Review
### Technical Factors in the Initial Adoption Phase of New Production Technologies  
The ramp-up phase is characterized by extreme instability resulting from various changes that are implemented in the process, products or equipment, which can be both intentional and unintentional. Consequently, the complexity of this period can increase significantly, leading to unpredictability and uncontrollability of the entire system, given that each adjustment of the system and of its parameters could lead to a decrease in production quantity. Therefore, the effectiveness of the ramp-up phase can be hardly predicted, and it is unlikely to reach the set targets of time, cost and quality [29]. One of the most relevant elements in the initial adoption phase of new production technologies is related to the supplier capabilities. Indeed, approximately 37% of production line disruptions during the ramp-up period are related to problems originating from the suppliers [1]. Differently, [PERSON] and [PERSON] (2019) [30] propose a model for original equipment manufacturer (OEM) supplier integration during ramp-up through a two-way communication about changes, costs, specification, resolution of technical problems and investments in new manufacturing technologies [30]. [PERSON] et al. (2018) [6] identify the behavior of the equipment among the causes of TH loss during the initial adoption phase of new technologies. Nominal conditions provided by the supplier of the technology are considered in the design phase of the system; however, during the integration of the equipment into the real system, more failure modes may emerge than those indicated by the supplier. Therefore, the greater the effort devoted to the design and planning of the ramp-up phase, the more efficient it will be in terms of time and cost [24]. On a different aspect, several scientific contributions discuss methodologies and approaches to optimize ramp-up conditions and equipment management. [PERSON] et al. (2016) [31] propose a model for the selection of machinery and equipment to obtain favorable conditions during the production start-up. The authors defined a target system for the evaluation of different technologies or production systems in which they considered parameters such as time to market and time to volume. However, the authors provide only a limited overview on the business processes without considering the whole supply chain. [PERSON] et al. (2016) [32] propose the use of the modular approach to counter the spread of the ramp-up effects in the production system, to reduce the complexity of the system, and to decouple the various modules. The limitation of this research lies in the lack of modular structures in already existing companies; therefore, the approach becomes not applicable in most industrial contexts. [PERSON] et al. (2018) [6] indicate the use of continuous improvement approaches to identify and remove disturbances affecting the behavior of the equipment, breakdowns of machinery and the integration of resources into the system with a perspective oriented to production. The study could be integrated with a methodology for reducing the variability of the TH obtained during the ramp-up phase, given that the performance improvement of a system could be partially hidden and difficult to trace in a system characterized by high variability. Finally, [PERSON] et al. (2015) [33] introduce a framework for ramp-up process management based on system complexity, while [PERSON] and [PERSON] (2018) [34] develop a model to stabilize production output by modeling uncertainties in the product design phase. In conclusion, though the technological factors of the ramp-up are largely studied in the scientific literature, they are never integrated with human factors in a comprehensive framework to evaluate the ramp-up period of new production technologies.