One comment I would like to say is why the aluminium tracks have to be replaced .This is a waste and also making the product more expensive. I’m sure the old tracks could be used again and the product re engineered so you could re use the old tracks
Net Promoter Score is a loyalty metric used as a KPI for customer experience, measured on a scale of -100 to +100.
To calculate the NPS, we first ask customers to answer the question "How likely is it that you would recommend this company to a friend or colleague?" on a scale of 0 - 10.
Customers who answer 0 - 6 are Detractors, 7 - 8 are Passives and 9 - 10 are Promoters. The NPS is the sum of % of Promoters - % Detractors.