## 4 Discussion and Conclusions  
This paper presents a state of the art approach to developing a precise list of the recurrent usability issues found in ERP systems. First, we have explored the existing literature on ERP system usability problems reported in usability studies. Second, the reported data is analyzed using the topic modeling approach of LDA to identify featured usability problems. The LDA algorithm output of each previously reported usability problem is mapped under each of the six topics. An expert manually analyzes these data, and each topic is titled as: (1) \"lack of feedback and complex interface\", (2) \"unstructured data and information overload\", (3) \"difficulty in searching and finding desired item/information in interface and error handling\", (4) \"interface customization problems\", (5) \"missing data and information\", and (6) \"contextual data and information organization issues\". Third, these topics are validated in the usability studies of ERP systems using three usability evaluation methods and, the results show the usability problems are associated with these topics. A total of 27 usability problems were found in three studies. The most common usability problems are \"difficulty searching and finding desired item/information in interface and error handling\" and \"missing data and information\". Moreover, the second most frequently reported problem is related to \"unstructured data and information overload\". In the usability studies, we have found ERP system usability problems related to all the topics. Lastly, we have developed the recommendations for ERP usability-related problems primarily based on [PERSON]'s ten heuristics, [PERSON]'s eight golden rules, and usability principles. The outcome of our paper is a precise list of ERP usability issues and recommendations to avoid them that can be used by the stakeholders in designing, developing, and evaluating ERP systems. The previous research was available with many different types of ERP system usability problems reported in numerous documents. This paper has combined these data and presented them using a unique approach by summarizing them optimally. Therefore, our study facilitated all interested stakeholders in improving their ERP systems based on previously reported experiences of usability problems; such a contribution is lacking in the previous research. The previous study [3; 24] developed the heuristics customization approach for the ERP systems usability evaluation criteria. In contrast, this study developed the criteria using a machine learning method from the collection of previously reported problems. Therefore, the results are justified, as the discovered topics cover all the previously developed usability criteria of ERP systems. The findings of this study are validated through usability evaluation of ERP systems in three different studies. However, the outcome can be generalized to various ERP systems. Recently, the results of usability evaluation studies reported problems with mobile, cloud, and SaaS interfaces. In [26], the authors evaluated two mobile ERP interfaces and reported the aspect of navigation and the presentation of the content causing a cognitive workload. This aspect is highlighted under the proposed recommendation of \"missing data and information\" in our contribution. The usability problems related to mobile ERP systems such as a complex interface, being hard to remember, trouble in finding desired information, a lack of help and documentation, the context of use and guidance, and information overload are reported in [47], which are precisely mapped with the outcomes of our study. In [48], the authors highlighted the usability problems of customization, information provision and feedback, the complexity of multistep tasks, data entry, visual design, searching, and navigation over lists while comparing the SAP S/4 HANA and Oracle Cloud ERP cloud-based ERP systems.