SELECT lpi.defName AS Prozess, SUM(lpi.lCount) AS Schleifendurchläufe FROM
(SELECT inst.definitionname AS defName, inst.instancename AS instName, act.loopcount AS lCount, inst.instanceid AS instId FROM
  (SELECT name AS instancename, id AS instanceid, definitionname FROM view_instance) AS inst
  JOIN
  (SELECT instanceID, name, loopcount FROM view_activity ORDER BY loopcount DESC) AS act ON act.loopcount IS NOT NULL AND act.instanceID = inst.instanceid
  GROUP BY inst.instanceid) AS lpi GROUP BY lpi.defName