Probably the most used metric to measure the productivity of knowledge workers is the number of hours spent on a task. Unfortunately, this breaks down in practice due to a number of factors:
kanban is a system originally developed by Toyota to reduce waste, and it can help you solve these thorny problems. kanban is all about limiting Work In Progress (WIP). You can only work on a limited number of tasks simultaneously in each phase of your workflow. WIP limits:
Once you have limited WIP, you solve the problems about multitasking (#3 and #4).
To solve the problem of manual time tracking (#1), you need a way to automatically track time. A digital kanban board uses drag and drop to track the time a task spends in each phase of your workflow.
To solve the problem of idle time tracking (#2), you can mark tasks when you aren't working on them. You mark tasks as "blocked" (when you need input from someone else) or "ready" (when you are finished, but someone else needs to continue the work). The software is smart enough to subtract the idle time from the total time you spend on a task.
You now know how to measure the productivity of your team(s) down to individual level, and you can see bottlenecks in your workflow you wouldn't notice otherwise.
Related Article: Finding the right task size in kanban