Index: trunk/grails-app/services/com/lemans/ds/fitment/PartFitmentManagerService.groovy
===================================================================
diff -u -r10003 -r10020
--- trunk/grails-app/services/com/lemans/ds/fitment/PartFitmentManagerService.groovy	(.../PartFitmentManagerService.groovy)	(revision 10003)
+++ trunk/grails-app/services/com/lemans/ds/fitment/PartFitmentManagerService.groovy	(.../PartFitmentManagerService.groovy)	(revision 10020)
@@ -4,6 +4,7 @@
 import grails.transaction.Transactional
 
 import java.sql.Timestamp
+import java.util.stream.Collectors
 
 /**
  * Created by vramisetti on 6/12/2017.
@@ -28,8 +29,9 @@
     Map createFitments(Map values, String username) {
         List errors = []
         String partNumber = values.partNumber
-        List modelYearIds = values.modelYearIds.unique()
-        List invalidModelYearIds = modelYearIds - modelYearService.findValidModelYearIds(modelYearIds)?.modelYearId
+        List modelYearIds = ((List) values.modelYearIds).parallelStream().distinct().collect(Collectors.toList())
+        List validModelYears = modelYearService.findValidModelYearIds(modelYearIds)?.modelYearId
+        List invalidModelYearIds = modelYearIds.parallelStream().filter { s -> !validModelYears.contains(s) }.collect(Collectors.toList())
         if (invalidModelYearIds) { errors << "Invalid model year's found $invalidModelYearIds" }
         if (!partService.partWithPartNumberExists(partNumber)) { errors << 'Invalid part' }
         if (!errors) {
@@ -47,7 +49,9 @@
     private List modelIdsToBeCreated(String partNumber, List modelYearIds) {
         List existingModelYearIds = partFitmentService.findFitmentsByPartNumberAndModelYearIds(partNumber,
                 modelYearIds, 'modelYearId')*.modelYearId
-        modelYearIds - existingModelYearIds
+        modelYearIds.parallelStream()
+                .filter { s -> !existingModelYearIds.contains(s) }
+                .collect(Collectors.toList())
     }
 
     /**