ok, it is a very small increase. maybe the calls are not dropping anymore, but instead they do a HO. Did you notice a decrease of TCH Drop Rate ?
In your BSC indicators table below, could you add the “Call_Drop_Rate” ? instead of the average 10 days before / after, could you do the average of the 10 busy hours of the 10 days before and after ?
Frankly, your changes are so small that it might just be a statistical effect. Have you checked those 10 days before and after ? I guess in 10 days you might have only one week-end during the “before” period and two week-ends during the “after” period. So that would definitely bias the average values… That’s just a thought 🙂