I’ve worked on a workflow study of a previous position. The study was based on the Kaizen (continuous improvement) event style to analyze efficiencies. I recommend looking for continuous improvement flow chart templates. I like creating diagrams using a Google Drive add-on called draw.io. It’s fairly easy to use. Continuous Improvement flowcharts usually also include the time it takes for each step to be completed and the waiting time between one step and another.
Rachel