Development of a new washing machine in olive oil extraction plant: A first application of usability-based approach

This paper suggests an approach based on usability engineering, used to assess the usability of machines and plants in the agrofood industry, aiming to enhance machines efficacy, efficiency and safety with a development focused on users’ needs. Furthermore, the article examines the validation of the suggested approach through its application in a case study regarding a washing machine for the production of extra virgin olive oil. Firstly, it was necessary to identify the target cluster. For this reason, only Tuscan high quality extra virgin olive oil manufacturers were selected. The selected producers are of between 30 and 65 years old, with working experience in the field of at least 10 years. Once the cluster was identified, through brainstorming, the critical phases of the process were identified. According to the results, the washing process was considered the most critical phase. The reached conclusions were analysed and translated into technical aspects through the Quality Function Deployment. The predominant needs to be introduced in the new washing machine were related to the reduction of processing time, the improvement of washing system, the reduction of water consumption, and the increase of worker safety. Successively, a virtual prototype was developed and tested with 8 experts. Afterwards, a usability test was performed with 15 users. Two different olive washing machines were evaluated (traditional vs new machine). The Wilcoxon signed-rank test was utilised for users’ scores interpretation. According to P-values (ranging from P<0.001 to P=0.008) several statistically significant differences emerged between the two washing machines. In particular, remarkable differences regarding efficacy, efficiency, usability, human-machine interaction, reliability and an increase in safety were highlighted. Moreover, the results indicate that the new washing machine is overall perceived as more usable machine. In conclusion, the results are encouraging and give robustness both to the proposed methodological approach and to the improvement of the new washing machine.