Other than Value Stream mapping, what is the best and easiest method to map the setup time of a process?

first it depends on what you need , if it's only for maping the process you can use swim lane or flow chart

This is a step by step guide to creating a current state value stream map, the first step in working towards your ideal state value stream and a truly lean system. Your current state value stream map is a team effort that is conducted by those people who are involved in the process, at the actual process, not by an expert locked in a room with a pile of procedures. Below we will go through; Selecting the product (family) to map VSM Symbols Defining the process boundaries The Process Steps Information Flows Process Data Calculating the Time Line Multiple Suppliers and Customers Interpreting the Data Next Steps (Ideal and future state maps)