diff --git a/src/PSUEvent.cpp b/src/PSUEvent.cpp
index c5ad0fe..f8cee21 100644
--- a/src/PSUEvent.cpp
+++ b/src/PSUEvent.cpp
@@ -37,14 +37,9 @@
     sdbusplus::asio::object_server& objectServer,
     std::shared_ptr<sdbusplus::asio::connection>& conn,
     boost::asio::io_context& io, const std::string& psuName,
-    const PowerState& powerState,
-    boost::container::flat_map<std::string, std::vector<std::string>>&
-        eventPathList,
-    boost::container::flat_map<
-        std::string,
-        boost::container::flat_map<std::string, std::vector<std::string>>>&
-        groupEventPathList,
-    const std::string& combineEventName, double pollRate) :
+    const PowerState& powerState, EventPathList& eventPathList,
+    GroupEventPathList& groupEventPathList, const std::string& combineEventName,
+    double pollRate) :
     objServer(objectServer)
 {
     std::string psuNameEscaped = sensor_paths::escapePathForDbus(psuName);
diff --git a/src/PSUEvent.hpp b/src/PSUEvent.hpp
index 3e066cf..4c705a4 100644
--- a/src/PSUEvent.hpp
+++ b/src/PSUEvent.hpp
@@ -30,6 +30,11 @@
 #include <string>
 #include <vector>
 
+using EventPathList =
+    boost::container::flat_map<std::string, std::vector<std::string>>;
+using GroupEventPathList =
+    boost::container::flat_map<std::string, EventPathList>;
+
 class PSUSubEvent : public std::enable_shared_from_this<PSUSubEvent>
 {
   public:
@@ -78,18 +83,12 @@
 class PSUCombineEvent
 {
   public:
-    PSUCombineEvent(
-        sdbusplus::asio::object_server& objectServer,
-        std::shared_ptr<sdbusplus::asio::connection>& conn,
-        boost::asio::io_context& io, const std::string& psuName,
-        const PowerState& powerState,
-        boost::container::flat_map<std::string, std::vector<std::string>>&
-            eventPathList,
-        boost::container::flat_map<
-            std::string,
-            boost::container::flat_map<std::string, std::vector<std::string>>>&
-            groupEventPathList,
-        const std::string& combineEventName, double pollRate);
+    PSUCombineEvent(sdbusplus::asio::object_server& objectServer,
+                    std::shared_ptr<sdbusplus::asio::connection>& conn,
+                    boost::asio::io_context& io, const std::string& psuName,
+                    const PowerState& powerState, EventPathList& eventPathList,
+                    GroupEventPathList& groupEventPathList,
+                    const std::string& combineEventName, double pollRate);
     ~PSUCombineEvent();
 
     sdbusplus::asio::object_server& objServer;
diff --git a/src/PSUSensorMain.cpp b/src/PSUSensorMain.cpp
index 4073d72..cf98f9b 100644
--- a/src/PSUSensorMain.cpp
+++ b/src/PSUSensorMain.cpp
@@ -131,14 +131,9 @@
 static boost::container::flat_map<std::string, std::string> sensorTable;
 static boost::container::flat_map<std::string, PSUProperty> labelMatch;
 static boost::container::flat_map<std::string, std::string> pwmTable;
-static boost::container::flat_map<std::string, std::vector<std::string>>
-    eventMatch;
-static boost::container::flat_map<
-    std::string,
-    boost::container::flat_map<std::string, std::vector<std::string>>>
-    groupEventMatch;
-static boost::container::flat_map<std::string, std::vector<std::string>>
-    limitEventMatch;
+static EventPathList eventMatch;
+static GroupEventPathList groupEventMatch;
+static EventPathList limitEventMatch;
 
 static std::vector<PSUProperty> psuProperties;
 static boost::container::flat_map<size_t, bool> cpuPresence;
@@ -147,12 +142,8 @@
 // Function CheckEvent will check each attribute from eventMatch table in the
 // sysfs. If the attributes exists in sysfs, then store the complete path
 // of the attribute into eventPathList.
-void checkEvent(
-    const std::string& directory,
-    const boost::container::flat_map<std::string, std::vector<std::string>>&
-        eventMatch,
-    boost::container::flat_map<std::string, std::vector<std::string>>&
-        eventPathList)
+void checkEvent(const std::string& directory, const EventPathList& eventMatch,
+                EventPathList& eventPathList)
 {
     for (const auto& match : eventMatch)
     {
@@ -177,24 +168,15 @@
 
 // Check Group Events which contains more than one targets in each combine
 // events.
-void checkGroupEvent(
-    const std::string& directory,
-    const boost::container::flat_map<
-        std::string,
-        boost::container::flat_map<std::string, std::vector<std::string>>>&
-        groupEventMatch,
-    boost::container::flat_map<
-        std::string,
-        boost::container::flat_map<std::string, std::vector<std::string>>>&
-        groupEventPathList)
+void checkGroupEvent(const std::string& directory,
+                     const GroupEventPathList& groupEventMatch,
+                     GroupEventPathList& groupEventPathList)
 {
     for (const auto& match : groupEventMatch)
     {
         const std::string& groupEventName = match.first;
-        const boost::container::flat_map<std::string, std::vector<std::string>>
-            events = match.second;
-        boost::container::flat_map<std::string, std::vector<std::string>>
-            pathList;
+        const EventPathList events = match.second;
+        EventPathList pathList;
         for (const auto& match : events)
         {
             const std::string& eventName = match.first;
@@ -221,12 +203,9 @@
 // in sysfs to see if xxx_crit_alarm xxx_lcrit_alarm xxx_max_alarm
 // xxx_min_alarm exist, then store the existing paths of the alarm attributes
 // to eventPathList.
-void checkEventLimits(
-    const std::string& sensorPathStr,
-    const boost::container::flat_map<std::string, std::vector<std::string>>&
-        limitEventMatch,
-    boost::container::flat_map<std::string, std::vector<std::string>>&
-        eventPathList)
+void checkEventLimits(const std::string& sensorPathStr,
+                      const EventPathList& limitEventMatch,
+                      EventPathList& eventPathList)
 {
     auto attributePartPos = sensorPathStr.find_last_of('_');
     if (attributePartPos == std::string::npos)
@@ -328,12 +307,8 @@
     boost::container::flat_set<std::string> directories;
     for (const auto& pmbusPath : pmbusPaths)
     {
-        boost::container::flat_map<std::string, std::vector<std::string>>
-            eventPathList;
-        boost::container::flat_map<
-            std::string,
-            boost::container::flat_map<std::string, std::vector<std::string>>>
-            groupEventPathList;
+        EventPathList eventPathList;
+        GroupEventPathList groupEventPathList;
 
         std::ifstream nameFile(pmbusPath);
         if (!nameFile.good())