diff --git a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/common/SearchParameterParser.java b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/common/SearchParameterParser.java
index 2c1cdddcd..47bd0df6a 100644
--- a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/common/SearchParameterParser.java
+++ b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/common/SearchParameterParser.java
@@ -39,8 +39,9 @@ public class SearchParameterParser {
             CommonConstants.PROPERTY_CREATED_ON);
 
     public static final String CRITERIA_INNER_SEPARATOR = ",";
+    public static final int NUM_PARTS_OF_FILTERS = 3;
 
-    final List<SearchCriteria<?>> searchCriteria;
+    private final List<SearchCriteria<?>> searchCriteria;
 
     public SearchParameterParser(final List<String> searchParameters) {
         searchCriteria = parseSearchParameters(searchParameters);
@@ -54,7 +55,7 @@ private List<SearchCriteria<?>> parseSearchParameters(final List<String> searchP
                 final String searchParameter = searchParameterList.get(i);
                 final String[] splittedSearchParam = StringUtils.split(searchParameter, CRITERIA_INNER_SEPARATOR);
 
-                if (splittedSearchParam.length < 3) {
+                if (splittedSearchParam.length < NUM_PARTS_OF_FILTERS) {
                     throw new IllegalArgumentException(("Illegal search parameter at index %s. "
                             + "Format should be <propertyName>,<operation>,<value>.").formatted(i));
                 }
diff --git a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java
index 40416024e..0a5ccdffb 100644
--- a/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java
+++ b/irs-policy-store/src/main/java/org/eclipse/tractusx/irs/policystore/services/PolicyPagingService.java
@@ -86,15 +86,16 @@ private PageImpl<PolicyWithBpn> applyPaging(final Pageable pageable, final List<
     /**
      * Builder for {@link Comparator} for sorting a list of {@link PolicyWithBpn} objects.
      */
-    static class PolicyComparatorBuilder {
+    private static class PolicyComparatorBuilder {
+        // TODO (mfischer): #639: maybe extract to separate class
 
         private final Pageable pageable;
 
-        PolicyComparatorBuilder(final Pageable pageable) {
+        /* package */ PolicyComparatorBuilder(final Pageable pageable) {
             this.pageable = pageable;
         }
 
-        public Comparator<PolicyWithBpn> build() {
+        /* package */ Comparator<PolicyWithBpn> build() {
 
             Comparator<PolicyWithBpn> comparator = null;
 
@@ -163,15 +164,16 @@ public Sort.Direction getSortDirection(final Pageable pageable, final String fie
     /**
      * Builder for {@link Predicate} for filtering a list of {@link PolicyWithBpn} objects.
      */
-    static class PolicyFilterBuilder {
+    private static class PolicyFilterBuilder {
+        // TODO (mfischer): #639: maybe extract to separate class
 
         private final List<SearchCriteria<?>> searchCriteriaList;
 
-        PolicyFilterBuilder(final List<SearchCriteria<?>> searchCriteriaList) {
+        /* package */ PolicyFilterBuilder(final List<SearchCriteria<?>> searchCriteriaList) {
             this.searchCriteriaList = searchCriteriaList;
         }
 
-        private Predicate<PolicyWithBpn> build() {
+        /* package */ Predicate<PolicyWithBpn> build() {
             Predicate<PolicyWithBpn> policyFilter = policy -> true;
 
             for (final SearchCriteria<?> searchCriteria : searchCriteriaList) {