Problem Management KPI's

Answer:
Problem Management KPI's can relate to problem's, incidents and changes. Here are few examples of PM KPI's:
Number of recurring incidents
Number of incidents without permanent resolution
Number of available Known Errors
Total numbers of problems
Size of current problem backlog for each IT service
Number of opened changes as a result of root cause elimination

You can find out more about Problem Management (and create further KPIs) in the article:
"How to make your ITIL/ISO 20000 Problem Management more effective with a Problem Record" https://advisera.com/20000academy/blog/2017/02/14/how-to-make-your-itiliso-20000-problem-management-more-effective-with-a-problem-record/
"ITIL Problem Management: getting rid of problems" https://advisera.com/20000academy/blog/2013/08/05/itil-problem-management-getting-rid-problems/
"ITIL Reactive and Proactive Problem Management: Two sides of the same coin" https://advisera.com/20000academy/knowledgebase/itil-reactive-proactive-problem-management-two-sides-coin/