diff --git a/gradlew b/gradlew
index a69d9cb..6bafaef 100755
--- a/gradlew
+++ b/gradlew
@@ -86,7 +86,7 @@ APP_NAME="Gradle"
 APP_BASE_NAME=${0##*/}
 
 # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+DEFAULT_JVM_OPTS='"-Xmx512m" "-Xms2048m"'
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
diff --git a/src/main/java/com/ffii/tsms/modules/data/service/StaffsService.kt b/src/main/java/com/ffii/tsms/modules/data/service/StaffsService.kt
index a9e0e35..a3a8218 100644
--- a/src/main/java/com/ffii/tsms/modules/data/service/StaffsService.kt
+++ b/src/main/java/com/ffii/tsms/modules/data/service/StaffsService.kt
@@ -7,6 +7,7 @@ import com.ffii.tsms.modules.common.SecurityUtils
 import com.ffii.tsms.modules.data.entity.*
 import com.ffii.tsms.modules.data.entity.projections.StaffSearchInfo
 import com.ffii.tsms.modules.data.web.models.NewStaffRequest
+import com.ffii.tsms.modules.data.web.models.NewStaffResponse
 import com.ffii.tsms.modules.data.web.models.SalaryEffectiveInfo
 import com.ffii.tsms.modules.user.entity.User
 import com.ffii.tsms.modules.user.entity.UserRepository
@@ -130,11 +131,17 @@ open class StaffsService(
     }
 
     @Transactional(rollbackFor = [Exception::class])
-    open fun saveStaff(req: NewStaffRequest): Staff {
+    open fun saveStaff(req: NewStaffRequest): NewStaffResponse {
         val checkStaffIdList: List<StaffSearchInfo> = staffRepository.findStaffSearchInfoByAndDeletedFalseOrderByStaffIdAsc()
         checkStaffIdList.forEach{ s ->
             if (s.staffId == req.staffId) {
-                throw UnprocessableEntityException("Duplicated StaffId Found")
+                return NewStaffResponse(
+                    id = null,
+                    name = req.name,
+                    staffId = req.staffId,
+                    message = "duplicated staff ID found",
+                    errorPosition = "code",
+                )
             }
         }
 //        val currentPosition = positionRepository.findById(req.currentPositionId).orElseThrow()
@@ -188,7 +195,7 @@ open class StaffsService(
             this.department = department
         }
 
-        staffRepository.saveAndFlush(staff)
+        val savedStaff = staffRepository.saveAndFlush(staff)
         if (!req.skillSetId.isNullOrEmpty()) {
             for (skillId in req.skillSetId) {
                 val skill = skillRepository.findById(skillId).orElseThrow()
@@ -213,10 +220,28 @@ open class StaffsService(
             positionLogService.savePositionLogs(staff, req.positionHistory)
         }
 
-        return staff
+        return NewStaffResponse(
+            id = savedStaff.id,
+            name = savedStaff.name,
+            staffId = savedStaff.staffId,
+            message = null,
+            errorPosition = null,
+        )
     }
     @Transactional(rollbackFor = [Exception::class])
-    open fun updateStaff(req: NewStaffRequest, staff: Staff): Staff {
+    open fun updateStaff(req: NewStaffRequest, staff: Staff): NewStaffResponse {
+        val checkStaffIdList: List<StaffSearchInfo> = staffRepository.findStaffSearchInfoByAndDeletedFalseOrderByStaffIdAsc()
+        checkStaffIdList.forEach{ s ->
+            if (s.id !== req.id && s.staffId == req.staffId) {
+                return NewStaffResponse(
+                    id = null,
+                    name = req.name,
+                    staffId = req.staffId,
+                    message = "duplicated staff ID found",
+                    errorPosition = "code",
+                )
+            }
+        }
         val args = java.util.Map.of<String, Any>("staffId", staff.id)
         if(!req.skillSetId.isNullOrEmpty()) {
             // remove all skills of the staff
@@ -298,26 +323,24 @@ open class StaffsService(
         if (req.salaryEffectiveInfo != null && req.delSalaryEffectiveInfo != null) {
             salaryEffectiveService.updateSalaryEffective(staff.id!!, req.salaryEffectiveInfo.sortedBy { it.date }, req.delSalaryEffectiveInfo)
         }
-//        else if (req.teamHistory != null && req.delTeamHistory != null) {
-//            teamLogService.editTeamLog(req.teamHistory, req.delTeamHistory)
-//        } else if (req.gradeHistory != null && req.delGradeHistory != null) {
-//            gradeLogService.editGradeLog(req.gradeHistory, req.delGradeHistory)
-//        } else if (req.positionHistory != null && req.delPositionHistory != null) {
-//            positionLogService.editPositionLog(req.positionHistory, req.delPositionHistory)
-//        }
-
-        return staffRepository.save(staff)
+        val savedStaff = staffRepository.saveAndFlush(staff)
+        return NewStaffResponse(
+            id = savedStaff.id,
+            name = savedStaff.name,
+            staffId = savedStaff.staffId,
+            message = null,
+            errorPosition = null,
+        )
     }
 
     @Transactional(rollbackFor = [Exception::class])
-    open fun saveOrUpdate(req: NewStaffRequest): Staff {
+    open fun saveOrUpdate(req: NewStaffRequest): NewStaffResponse {
         val staff = if(req.id != null) find(req.id).get() else Staff()
         if (req.id != null) {
-            updateStaff(req, staff)
+            return updateStaff(req, staff)
         } else {
-            saveStaff(req)
+            return saveStaff(req)
         }
-        return staff;
     }
 
     open fun combo(args: Map<String, Any>): List<Map<String, Any>> {
diff --git a/src/main/java/com/ffii/tsms/modules/data/web/StaffsController.kt b/src/main/java/com/ffii/tsms/modules/data/web/StaffsController.kt
index 6898e43..b115d5f 100644
--- a/src/main/java/com/ffii/tsms/modules/data/web/StaffsController.kt
+++ b/src/main/java/com/ffii/tsms/modules/data/web/StaffsController.kt
@@ -8,6 +8,7 @@ import com.ffii.tsms.modules.data.entity.Staff
 import com.ffii.tsms.modules.data.entity.projections.StaffSearchInfo
 import com.ffii.tsms.modules.data.service.StaffsService
 import com.ffii.tsms.modules.data.web.models.NewStaffRequest
+import com.ffii.tsms.modules.data.web.models.NewStaffResponse
 import jakarta.servlet.http.HttpServletRequest
 import jakarta.validation.Valid
 import liquibase.hub.model.Project
@@ -74,7 +75,7 @@ class StaffsController(private val staffsService: StaffsService) {
         )
     }
     @PostMapping("/save")
-    fun saveStaff(@Valid @RequestBody newStaff: NewStaffRequest): Staff {
+    fun saveStaff(@Valid @RequestBody newStaff: NewStaffRequest): NewStaffResponse {
         return staffsService.saveOrUpdate(newStaff)
     }
 }
\ No newline at end of file
diff --git a/src/main/java/com/ffii/tsms/modules/data/web/models/NewStaffResponse.kt b/src/main/java/com/ffii/tsms/modules/data/web/models/NewStaffResponse.kt
index 6e8c02d..681518b 100644
--- a/src/main/java/com/ffii/tsms/modules/data/web/models/NewStaffResponse.kt
+++ b/src/main/java/com/ffii/tsms/modules/data/web/models/NewStaffResponse.kt
@@ -3,7 +3,9 @@ package com.ffii.tsms.modules.data.web.models
 import com.ffii.tsms.modules.data.entity.Staff
 
 data class NewStaffResponse (
-    val staff: Staff,
-    val message: String,
-
+    val id: Long?,
+    val name: String?,
+    val staffId: String?,
+    val message: String?,
+    val errorPosition: String?, // e.g. duplicated code
 )
\ No newline at end of file