What it shows
One bar per split of a bucket, each 100% of that split's cost in the period: planned or reactive prevention, process or product control, rework or scrap, own or supplier-caused internal failure, and product or service external failure. Grey is the cost of sets without a sub-bucket yet.
Why it matters in manufacturing
The buckets say how much quality costs; the sub-buckets say what kind of cost it is. That points at the action to take: plan more prevention, control the process instead of checking the product, recover more material, charge suppliers back, or fix the service around the product.
How to read it
Compare the dark and light parts of each bar, and hover for the amounts. A large grey part means the split is incomplete: give those sets a sub-bucket in master data. Bars without cost are empty.
What good looks like
Mostly dark blue in the planned prevention, process control and rework bars, mostly light blue in the supplier and service bars, and little grey anywhere.