The graph has 2 series (gap + duration) for each activity per customer (shown in columns).
The macro can gererate more phases, but the chart as it is now will not show more than 9 activities per customer.
Also the ranges for the number of customers is now set to 11, so if you have more customers those are not shown on the chart (height).
That is what I meant to make the size of the chart dynamic.
But if you have not so many customers and not many activities per customer, my example will do the job.