The calculation scheme is very subjective, but with all this - for statistics, this figure is very, very interesting. And, looking a little ahead, I will say that we checked in a real service - and the “hit the mark” was in more than 80%, which is a very serious indicator.
The program maintenance repair is divided into statuses. Each repair status is characterized by a designated maximum execution time. It may be exceeded, but this is not encouraged.
The standard set of statuses for ordinary repairs looks like this:

In the "event" column there is a set of properties for the status. And so it looks like:

It is by properties that one should be guided in statuses, since far from all points are important for our analysis. Looking only related to the diagnosis, repair and waiting parts.
Each repair has a level of “customer satisfaction”; for a customer, you can get an average value or a sample for a group of equipment being repaired.
1. Choose a customer. We are looking for all the repairs on it, and as a rule they are from one to three. More than 3 is extremely rare, and in case of excess we transfer the client to the group "regular customers". If we have all 3 different devices, then we add 50 points. If 2 different devices, then add 25 points. If there is at least one repetition of repair - then 10/0 points (3/2 repair). If at least one repair has less than 10 points of “contentment”, then we deduct 10 points from the calculation.
1.a. If the client is an intermediary, then we add 25 points to it.
1.b. If a regular customer, then add him 20 points.
2. We identify the level of discipline of repair, namely, in part of the performance of work by the engineer. The engineer changed the statuses in one gulp or did it in stages. If the "salvo", then 0 points. If the status changes went step by step, with the time between shifts of 3 minutes, but no more than the designated time for the status, then we add 10 points.
3. We study the cost of repair relative to the average value of the cost of all repairs. Also - for parts that have been inserted into the repair, the difference between the price of receipt and the price in the sum of the cost of repair is revealed. If the "cost cheat" for parts is less than 10%, then +7 points. If the "cost cheat" for parts is less than 30%, then +5 points. If the "cost cheat" for parts more than 50%, then minus 10 points. If the total cost of repair is less than the average value of more than 10%, then +10 points, if the cost is within ± 10% - then 5 points, if it is above 10% - then 0 points.
4. If the client has viewed the repair card through the “client’s personal account”, then we will add 5 points. If you still leave a review, where there is the word "thank you" and there is no mate / curse, then add another 10 points. If there is at least one dirty word in the comments, then immediately minus 40 points. There are sometimes very funny comments, such as “thank you, b ** for oh *** ny repair”.
5. Term repair. If the repair was carried out within 2 working days, then add 10 points. If within 5 days, then add 5 points. If more than 14 days, then minus 15 points. More than a month - then minus 30 points.
6. If the client took the vehicle within 2 days after the status “ready to issue” - then plus 5 points.
7. For each service engineer who makes repairs, there is an assessment of the quality of their work. The value is from 0 to 99. On average, good masters have 60-70 points. The description of the counting algorithm is more objective, but we will describe the mechanism later, if necessary. So, if the master who made the repair of equipment in the order, has more than 60 points - then plus 5 points. If less, then nothing is added.
8. Loyalty score. Sets the manager - from minutes 30 to plus 30 points. All this is set at the discretion of the manager, who communicates with the client.
9. If the repair was not successful - then the score is reset.
As a result, if the sum of points exceeds 99, we truncate it to 99.
A good repair by statuses looks like this:

This is the second repair client. Previously, he also repaired a mobile phone in the same service center. Now the laptop, and the analysis of the status of repairs gave a positively high score.
I can upset many service providers. Of the 3,500 customer repairs with 49 points or more, about 250-270 are recruited. If you lower the score to 40, then already 550-700 customers. And, "cherry on the cake" - the average score of 37.
It was this repair (+ previous) that gave the customer 67 points of “satisfaction”.