Abstract—Simulation can be used for analysis, prediction and optimization of business processes. But models often differ from reality. Data mining techniques can be used for improving these models based on observations of process and resource behavior from detailed event logs. More accurate process models can be used not only for analysis and optimization, but for prediction and recommendation. This paper focuses on decision mining and the duration of tasks in conjunction with personal performance based on case data, workload, and other factors. Some existing ideas are an improvement and others are new. Part of the research was validated on real data. Keywords-business process simulation; business process intelligence; data mining; process ...