# The Human Performance Impact on OEE in the Adoption of New Production Technologies
## 2 Literature Review
### Human Factors in the Initial Adoption Phase of New Production Technologies  
The goal of ramp-up phase management is to reduce or control uncertainty and instability of the start-up. In this context, the process knowledge and the learning of employees become key points to reach this objective. Learning leads to a better understanding of production processes and improves performance in terms of quality, time and cost [20]. [PERSON] and [PERSON] (2011) [20] highlight the importance of favoring the phenomenon of spillover between consecutive ramp-ups and between individuals to improve the performance of the system and to accelerate learning. In the knowledge transfer between consecutive ramp-ups, the authors make a distinction between explicit knowledge, given by precise and codified explanations, and tacit knowledge, given by subtle knowledge that is related to a person and is based on experiences and insights. Companies can choose different ways for knowledge transfer to occur in order to equip workers with the required skills during the ramp-up phase of production: the transfer of explicit knowledge is simple and easy--given that this type of information is generally written--while, on the contrary, the transfer of tacit knowledge is more difficult because it is individual and difficult to code [21]. Usually, the transfer of tacit knowledge can occur through observation and imitation of others--therefore, social interaction--when a new activity is performed [21]. This phenomenon is even more relevant since human operators involved in the ramp-up process may experience a slower learning curve than planned, causing an extension of the processing time, excessive corrective maintenance time, or inaccurate inspection operations [6]. [PERSON] et al. (2018) [18] focus the attention on the role played by the organizational structure for learning and for production start-up management. Indeed, the authors observe that several departments are involved in this phase whose influence and importance vary in relation to its progress. Generally, a ramp-up manager is identified who has the purpose of guaranteeing continuous process management and participating during the various phases. Moreover, the authors identified two main organizational types:  
1. Non-dedicated operators: the knowledge and skills of the staff can be shared between the functional departments, and the employees are involved in the phase of ramp-up in addition to regular work. The benefit deriving from this structure is the consistently high staff utilization rate, but problems could be generated if conflicts occur between the regular organization and the one dedicated to the project;
2. Dedicated operators: employees belong to the regular departments, though they are released from the job routine and are completely dedicated to the ramp-up phase during the project lifespan. This leads to a better direct focus on the implementation of the project and a greater effect of learning. However, as a disadvantage, there is a rate of use of human resources which is lower than the first approach. In the same context, [PERSON] et al. (2007) [22] propose to use dedicated teams for the launch of new products; these teams are to be used during the modification of the technical characteristics of the product. This would avoid criticalities due to late implementation of different types of changes, which can cause problems in terms of target values imposed for timing, quality and cost. To counteract possible inefficiencies, the authors proposed the presence of two dedicated teams: one short-term team created to solve specific technical problems, and one long-term team dedicated to preventive actions related to the new process. With this approach, knowledge would be preserved between consequent ramp-ups. Another important aspect during production start-up management is the training and learning of operators.