The relationship between NPS and MTTR is certainly precarious. To fully understand it, we need to take a very customer-centric look into incident management. So let’s look at the definitions of both Key Performance Indicators and then translate them to the ‘language of the customer’.
Net Promoter Score (NPS)
The Net Promoter Score is an index ranging from -100 to 100 that measures the willingness of customers to recommend a company’s products or services to others. It is used as a proxy for gauging the customer’s overall satisfaction with a company’s product or service and the customer’s loyalty to the brand.
In practice, NPS is calculated by subtracting the percentage of customers who are Detractors from the percentage of customers who are Promoters. For purposes of calculating a Net Promoter Score, Passives count towards the total number of respondents, but do not directly affect the overall net score.
According to this definition, to achieve a positive NPS, the amount of customers likely to recommend a product or service have to be higher than the amount of the ones who are not.
Who are Promoters?
Customers that mark 9 or 10 on the “How likely are you to recommend this service” question in the Customer Satisfaction surveys are considered Promoters. They are the champions of your service.
Who are Passives?
Customers that mark 7 or 8 on the “How likely are you to recommend this service” question in the Customer Satisfaction surveys are considered Passives. These are happy customers, but they do not factor in the calculation of NPS.
Who are Detractors?
Customers that mark 6 or less on the “How likely are you to recommend this service” question in the Customer Satisfaction surveys are considered Detractors. These are the disappointed customers that can hurt your brand.
Example: Promoters 34,5%, Detractors 31%, Passives 34,5% => NPS is 3.50
Mean Time To Resolution (MTTR)
Mean Time to Resolve (MTTR) is a service level metric for service desks that measures the average elapsed time from when an incident is reported until the incident is resolved. It is typically measured in hours, and refers to business hours, not clock hours.
Example: An incident that is reported at 4:00 pm on a Friday and closed out at 4:00 pm the following Monday, for example, will have a resolution time of 8 business hours, not 72 clock hours.
The performance targets for MTTR are usually tied to Service Level Agreements, or SLAs. Resolving incidents within deadline is critical to customer satisfaction. This means that if we plot MTTR performance in and out of SLA to the same scale that defines customers as Promoters, Passives and Detractors, we can discover the concrete relationship between NPS and MTTR. And if we take an arbitrary incident SLA for Priority 1 tickets to be 6 hours, then we can come up with the performance needed to create a Promoter.
“Promoter” Levels of MTTR
To contribute to a score of 9 or 10 in the customer satisfaction survey, MTTR has to definitely be within SLA, even faster. This means that any Priority 1 issue resolution within the first 3 hours is sure to contribute to creating a Promoter.
“Passive” Levels of MTTR
To get a score of 7 or 8, the MTTR still has to be resolved within SLA, meaning resolution times between 3 and 6 hours.
“Detractor” Levels of MTTR
MTTR that violates the SLA is almost guaranteed to contribute to a very low customer satisfaction score, and thusly in creating a Detractor.
Understanding the relationships between performance metrics like NPS and MTTR is the first step towards resolving the struggles of an incident management department and ultimately, improving the processes that time and time again prove to be the key to customer’s hearts.