Perceived Workload has a subjective character trait, but I would like to find a way how one can measure for example the perceived workload from any individual. Here I mean the workload, which is caused by a single software on the person, who has to work with it.
The software I am talking about provides work items as some part of a workflow from a project team. And here I would like to find out, what is circa the optimal amount of work items (for example daily) for one single stakeholder in order to avoid fatigue or cognitive overload. (The work items themselves always take circa same efforts and time)
Are there any best practices for my matter or any (scientifically) proven ways to do this?