Kanban - Workflow Heat Map

What is the challenge?

When running an effective Kanban system it's important to know where the bottlenecks in the process are.

What is the impact?

Currently I have to export the data to a spreadsheet to work out the problem stages.

Describe your idea

I would like a report where I can mark up which states on my workboard are "work" or "wait" stages.

The view the data in a heat map so i can see where the work spends the most time. Using the work and wait stages calculate how efficient my current process is.