Abstract Background: Expanding nursing workload is a worldwide problem. However, any nursing workload assessment (NWA) tool requires complicated analyses of the nursing job profile. To determine the imbalance in time assignments across all nursing operations and to reduce nursing workload, a nursing job survey was conducted. Methods: A total of 25 major job categories, common to all hospital wards, were identified, and an NWA tool was developed for efficient analyses to feature easy/flexible entry of the time spent for each job category and real-time visual profiling of job time allocation. The profile could be divided by job categories, wards, shifts, and years. Results: From the preliminary analyses, undesirable time allocation was revealed in several job categories, especially the time for recording and other nonessential nursing operations. Using the analytical functions of the NWA tool between 2014 and 2016, a series of corrective measures were successfully taken to many job categories, and they were found to be effective. Consequently, excessive overtime workload was reduced from 125 min/day/nurse in 2014 to 100 and 100 min/day/ nurse in 2015 and 2016, respectively. Conclusion: Notable improvements in nursing workload and time allocation for attentive patient care could be achieved employing the novel user-aimed NWA tool.