diff --git a/me.smartstore/src/Main.java b/me.smartstore/src/Main.java
new file mode 100644
index 00000000..8ef738b9
--- /dev/null
+++ b/me.smartstore/src/Main.java
@@ -0,0 +1,8 @@
+import customer.Customers;
+
+public class Main {
+    public static void main(String[] args) {
+        SmartStoreApp.getInstance().test().run();
+        //SmartStoreApp.getInstance().run();
+    }
+}
diff --git a/me.smartstore/src/SmartStoreApp.java b/me.smartstore/src/SmartStoreApp.java
new file mode 100644
index 00000000..8bcfb57c
--- /dev/null
+++ b/me.smartstore/src/SmartStoreApp.java
@@ -0,0 +1,57 @@
+import customer.Customer;
+import customer.Customers;
+import group.Group;
+import group.GroupType;
+import group.Groups;
+import group.Parameter;
+import menu.*;
+
+
+public class SmartStoreApp {
+    private final Groups allGroups = Groups.getInstance();
+    private final Customers allCustomers = Customers.getInstance();
+    private final MainMenu mainMenu = MainMenu.getInstance();
+    private static SmartStoreApp smartStoreApp;
+
+    public static SmartStoreApp getInstance(){
+        if(smartStoreApp == null){
+            smartStoreApp = new SmartStoreApp();
+        }
+        return smartStoreApp;
+    }
+    private SmartStoreApp(){}
+    public void details(){
+        System.out.println("\n\n===========================================");
+        System.out.println(" Title : SmartStore Customer Classification");
+        System.out.println(" Release Date : 23.04.27");
+        System.out.println(" Copyright 2023 Eunbin All rights reserved.");
+        System.out.println("===========================================\n");
+    }
+    public SmartStoreApp test(){
+        allGroups.add(new Group(new Parameter(10, 100000), GroupType.GENERAL));
+        allGroups.add(new Group(new Parameter(20, 200000), GroupType.VIP));
+        allGroups.add(new Group(new Parameter(30, 300000), GroupType.VVIP));
+
+        for (int i = 0; i < 26; i++) {
+            allCustomers.add(new Customer(
+                    Character.toString(
+                            (char) ('a' + i)),
+                    (char) ('a' + i) + "123",
+                    ((int) (Math.random() * 5) + 1) * 10,
+                    ((int) (Math.random() * 5) + 1) * 100000));
+        }
+
+        System.out.println("allCustomers = " + allCustomers);
+        System.out.println("allGroups = " + allGroups);
+
+        // @TODO: refresh do not implemented yet.
+        allCustomers.refresh();
+
+        return this; // smartStoreApp
+    }
+    public void run() {
+        details();
+        mainMenu.manage();
+    }
+
+}
diff --git a/me.smartstore/src/arrays/Collections.java b/me.smartstore/src/arrays/Collections.java
new file mode 100644
index 00000000..e8d0c436
--- /dev/null
+++ b/me.smartstore/src/arrays/Collections.java
@@ -0,0 +1,16 @@
+package arrays;
+
+public interface Collections<T> {
+    // 데이터를 가지고 있는 객체가 아님
+    // 구현 해야하는 메소드의 정보만 가지고 있음 (인터페이스)
+
+    int size();
+    T get(int index);
+    void set(int index, T object);
+    int indexOf(T object);
+    void add(T object);
+    void add(int index, T object);
+    T pop();
+    T pop(int index);
+    T pop(T object);
+}
diff --git a/me.smartstore/src/arrays/DArray.java b/me.smartstore/src/arrays/DArray.java
new file mode 100644
index 00000000..c6726a5c
--- /dev/null
+++ b/me.smartstore/src/arrays/DArray.java
@@ -0,0 +1,153 @@
+package arrays;
+
+import exception.ElementNotFoundException;
+import exception.EmptyArrayException;
+import exception.NullArgumentException;
+
+public class DArray<T> implements Collections<T> { // Dynamic Array
+
+    protected static final int DEFAULT = 10;
+
+    protected T[] arrays;
+    protected int size;
+    protected int capacity;
+
+    public DArray() throws ClassCastException {
+        arrays = (T[]) new Object[DEFAULT];
+        capacity = DEFAULT;
+    }
+
+    public DArray(int initial) throws ClassCastException {
+        arrays = (T[]) new Object[initial];
+        capacity = initial;
+    }
+
+    public DArray(T[] arrays) {
+        this.arrays = arrays;
+        capacity = arrays.length;
+        size = arrays.length;
+    }
+
+    /////////////////////////////////////////
+    // add, set, get, pop, indexOf, size, capacity (for dynamic-sized array)
+
+    @Override
+    public int size() {
+        return size;
+    }
+
+    // 배열에 얼마나 capacity 남아있는지 외부에 알려줄 필요가 없기 때문에 <protected>으로 정의
+    protected int capacity() {
+        return capacity;
+    }
+
+    @Override
+    public T get(int index) throws IndexOutOfBoundsException {
+        if (index < 0 || index >= size) throw new IndexOutOfBoundsException();
+        return arrays[index];
+    }
+
+    /**
+     * @param: ...
+     * @return: ...
+     * @throws: IndexOutOfBoundsException
+     * @throws: NullArgumentException
+     * */
+    @Override
+    public void set(int index, T object) throws IndexOutOfBoundsException, NullArgumentException {
+        if (index < 0 || index >= size) throw new IndexOutOfBoundsException();
+        if (object == null) throw new NullArgumentException();
+
+        arrays[index] = object;
+    }
+
+    @Override
+    public int indexOf(T object) throws NullArgumentException, ElementNotFoundException {
+        if (object == null) throw new NullArgumentException(); // not found (instead of throwing exception)
+
+        for (int i = 0; i < size; i++) {
+            if (arrays[i] == null) continue;
+            if (arrays[i].equals(object)) return i;
+        }
+        throw new ElementNotFoundException(); // not found
+    }
+
+    // 배열의 cap이 부족한 경우
+    @Override
+    public void add(T object) throws NullArgumentException {
+        if (object == null) throw new NullArgumentException(); // if argument is null, do not add null value in array
+
+        if (size < capacity) {
+            arrays[size] = object;
+            size++;
+        } else {
+            grow();
+            add(object);
+        }
+    }
+
+    @Override
+    public void add(int index, T object) throws IndexOutOfBoundsException, NullArgumentException {
+        if (index < 0 || index >= size) throw new IndexOutOfBoundsException();
+        if (object == null) throw new NullArgumentException();
+
+        if (size < capacity) {
+            for (int i = size-1; i >= index ; i--) {
+                arrays[i+1] = arrays[i];
+            }
+            arrays[index] = object;
+            size++;
+        } else {
+            grow();
+            add(index, object);
+        }
+    }
+
+    @Override
+    public T pop() {
+//        if (size == 0) return null;
+//
+//        T popElement = arrays[size-1];
+//        arrays[size-1] = null;
+//        size--;
+//        return popElement;
+        return pop(size-1);
+    }
+
+    @Override
+    public T pop(int index) throws IndexOutOfBoundsException {
+        if (size == 0) throw new EmptyArrayException();
+        if (index < 0 || index >= size) throw new IndexOutOfBoundsException();
+
+        T popElement = arrays[index];
+        arrays[index] = null; // 삭제됨을 명시적으로 표현
+
+        for (int i = index+1; i < size; i++) {
+            arrays[i-1] = arrays[i];
+        }
+        arrays[size-1] = null;
+        size--;
+        return popElement;
+    }
+
+    @Override
+    public T pop(T object) {
+        return pop(indexOf(object));
+    }
+
+    protected void grow() {
+        capacity *= 2; // doubling
+        arrays = java.util.Arrays.copyOf(arrays, capacity);
+
+        // size는 그대로
+    }
+
+    @Override
+    public String toString() {
+        String toStr = "";
+        for (int i = 0; i < size; i++) {
+            toStr += (arrays[i] + "\n");
+        }
+        return toStr;
+    }
+}
diff --git a/me.smartstore/src/customer/Customer.java b/me.smartstore/src/customer/Customer.java
new file mode 100644
index 00000000..a350d81e
--- /dev/null
+++ b/me.smartstore/src/customer/Customer.java
@@ -0,0 +1,109 @@
+package customer;
+
+import group.Group;
+import jdk.jfr.Description;
+
+import java.util.Objects;
+
+public class Customer implements Comparable<Customer> {
+    private String cName;
+    private String cId;
+    private Integer totalTime;
+    private Integer totalPay;
+
+
+    private Group group;
+    //refresh 함수가 호출되는 경우 -> 분류기준이 바뀔때, 새로운 고객이 들어올때
+
+    public Customer(){
+
+    }
+    public Customer(String cName, String cId) {
+        this.cName = cName;
+        this.cId = cId;
+    }
+
+    public Customer(String cName, String cId, Integer totalTime, Integer totalPay) {
+        this.cName = cName;
+        this.cId = cId;
+        this.totalTime = totalTime;
+        this.totalPay = totalPay;
+    }
+    public Customer(String cName, String cId, Integer totalTime, Integer totalPay, Group group) {
+        this.cName = cName;
+        this.cId = cId;
+        this.totalTime = totalTime;
+        this.totalPay = totalPay;
+        this.group = group;
+    }
+
+    public String getcName() {
+        return cName;
+    }
+
+    public void setcName(String cName) {
+        this.cName = cName;
+    }
+
+    public String getcId() {
+        return cId;
+    }
+
+    public void setcId(String cId) {
+        this.cId = cId;
+    }
+
+    public Integer getTotalTime() {
+        return totalTime;
+    }
+
+    public void setTotalTime(Integer totalTime) {
+        this.totalTime = totalTime;
+    }
+
+    public Integer getTotalPay() {
+        return totalPay;
+    }
+
+    public void setTotalPay(Integer totalPay) {
+        this.totalPay = totalPay;
+    }
+    public Group getGroup() {
+        return group;
+    }
+
+    public void setGroup(Group group) {
+        this.group = group;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Customer customer = (Customer) o;
+        return Objects.equals(cId, customer.cId);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(cId);
+    }
+
+    @Override
+    public String toString() {
+        return "Customer{" +
+                "cName='" + cName + '\'' +
+                ", cId='" + cId + '\'' +
+                ", totalTime=" + totalTime +
+                ", totalPay=" + totalPay +
+                ", group=" + group+
+                '}';
+    }
+    /**
+     * 정렬을 위한 메소드
+     */
+    @Override
+    public int compareTo(Customer o) {
+        return this.cName.compareTo(o.cName);
+    }
+}
diff --git a/me.smartstore/src/customer/Customers.java b/me.smartstore/src/customer/Customers.java
new file mode 100644
index 00000000..79a22fe2
--- /dev/null
+++ b/me.smartstore/src/customer/Customers.java
@@ -0,0 +1,51 @@
+package customer;
+
+import arrays.DArray;
+import group.Group;
+import group.GroupType;
+import group.Groups;
+
+public class Customers extends DArray<Customer>{
+    private final Groups allGroups = Groups.getInstance();
+    private static Customers allCustomers;
+
+    public static Customers getInstance() {
+        if (allCustomers == null) {
+            allCustomers = new Customers();
+        }
+        return allCustomers;
+    }
+
+    private Customers() {}
+
+    // refresh 함수가 호출되는 경우
+    // 1. 분류기준 바뀔 때
+    // 2. 새로운 고객이 들어올 때
+    public void refresh() {
+        for(int i=0; i< allCustomers.size(); i++){
+            Customer customer = allCustomers.get(i);
+            Group group = findGroup(customer.getTotalTime(), customer.getTotalPay());
+            customer.setGroup(group);
+        }
+    }
+
+    /**
+     * 시간과 돈을 매개변수로 받아 해당하는 등급을 반환
+     * */
+    public Group findGroup(int totalTime, int totalPay){
+        try {
+            if(totalTime >= allGroups.find(GroupType.VVIP).getParameter().getMinTime() && totalPay>=allGroups.find(GroupType.VVIP).getParameter().getMinPay()){
+                return allGroups.find(GroupType.VVIP);
+            } else if (totalTime >= allGroups.find(GroupType.VIP).getParameter().getMinTime() && totalPay>=allGroups.find(GroupType.VIP).getParameter().getMinPay()) {
+                return allGroups.find(GroupType.VIP);
+            } else if (totalTime >= allGroups.find(GroupType.GENERAL).getParameter().getMinTime() && totalPay>=allGroups.find(GroupType.GENERAL).getParameter().getMinPay()) {
+                return allGroups.find(GroupType.GENERAL);
+            } else{
+                return allGroups.find(GroupType.NONE);
+            }
+        } catch (NullPointerException e){
+            return null;
+        }
+    }
+
+}
diff --git a/me.smartstore/src/exception/ArrayEmptyException.java b/me.smartstore/src/exception/ArrayEmptyException.java
new file mode 100644
index 00000000..1a0538a2
--- /dev/null
+++ b/me.smartstore/src/exception/ArrayEmptyException.java
@@ -0,0 +1,15 @@
+package exception;
+
+
+import util.Message;
+
+public class ArrayEmptyException extends RuntimeException {
+
+    public ArrayEmptyException() {
+        super(Message.ERR_MSG_INVALID_ARR_EMPTY);
+    }
+
+    public ArrayEmptyException(String message) {
+        super(message);
+    }
+}
diff --git a/me.smartstore/src/exception/ElementNotFoundException.java b/me.smartstore/src/exception/ElementNotFoundException.java
new file mode 100644
index 00000000..f163a3e8
--- /dev/null
+++ b/me.smartstore/src/exception/ElementNotFoundException.java
@@ -0,0 +1,22 @@
+package exception;
+
+public class ElementNotFoundException extends RuntimeException {
+    public ElementNotFoundException() {
+    }
+
+    public ElementNotFoundException(String message) {
+        super(message);
+    }
+
+    public ElementNotFoundException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public ElementNotFoundException(Throwable cause) {
+        super(cause);
+    }
+
+    public ElementNotFoundException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+}
diff --git a/me.smartstore/src/exception/EmptyArrayException.java b/me.smartstore/src/exception/EmptyArrayException.java
new file mode 100644
index 00000000..4ece8b3b
--- /dev/null
+++ b/me.smartstore/src/exception/EmptyArrayException.java
@@ -0,0 +1,22 @@
+package exception;
+
+public class EmptyArrayException extends RuntimeException {
+    public EmptyArrayException() {
+    }
+
+    public EmptyArrayException(String message) {
+        super(message);
+    }
+
+    public EmptyArrayException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public EmptyArrayException(Throwable cause) {
+        super(cause);
+    }
+
+    public EmptyArrayException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+}
diff --git a/me.smartstore/src/exception/InputEmptyException.java b/me.smartstore/src/exception/InputEmptyException.java
new file mode 100644
index 00000000..2327adb2
--- /dev/null
+++ b/me.smartstore/src/exception/InputEmptyException.java
@@ -0,0 +1,15 @@
+package exception;
+
+
+import util.Message;
+
+public class InputEmptyException extends RuntimeException {
+
+    public InputEmptyException() {
+        super(Message.ERR_MSG_INVALID_INPUT_EMPTY);
+    }
+
+    public InputEmptyException(String message) {
+        super(message);
+    }
+}
diff --git a/me.smartstore/src/exception/InputEndException.java b/me.smartstore/src/exception/InputEndException.java
new file mode 100644
index 00000000..8af309b5
--- /dev/null
+++ b/me.smartstore/src/exception/InputEndException.java
@@ -0,0 +1,14 @@
+package exception;
+
+
+import util.Message;
+
+public class InputEndException extends RuntimeException {
+    public InputEndException() {
+        super(Message.ERR_MSG_INPUT_END);
+    }
+
+    public InputEndException(String message) {
+        super(message);
+    }
+}
diff --git a/me.smartstore/src/exception/InputFormatException.java b/me.smartstore/src/exception/InputFormatException.java
new file mode 100644
index 00000000..1ed77d99
--- /dev/null
+++ b/me.smartstore/src/exception/InputFormatException.java
@@ -0,0 +1,14 @@
+package exception;
+
+
+import util.Message;
+
+public class InputFormatException extends RuntimeException {
+    public InputFormatException() {
+        super(Message.ERR_MSG_INVALID_INPUT_FORMAT);
+    }
+
+    public InputFormatException(String message) {
+        super(message);
+    }
+}
diff --git a/me.smartstore/src/exception/InputRangeException.java b/me.smartstore/src/exception/InputRangeException.java
new file mode 100644
index 00000000..35b0f4ad
--- /dev/null
+++ b/me.smartstore/src/exception/InputRangeException.java
@@ -0,0 +1,14 @@
+package exception;
+
+
+import util.Message;
+
+public class InputRangeException extends RuntimeException {
+    public InputRangeException() {
+        super(Message.ERR_MSG_INVALID_INPUT_RANGE);
+    }
+
+    public InputRangeException(String message) {
+        super(message);
+    }
+}
diff --git a/me.smartstore/src/exception/InputTypeException.java b/me.smartstore/src/exception/InputTypeException.java
new file mode 100644
index 00000000..58b6a149
--- /dev/null
+++ b/me.smartstore/src/exception/InputTypeException.java
@@ -0,0 +1,14 @@
+package exception;
+
+
+import util.Message;
+
+public class InputTypeException extends RuntimeException {
+    public InputTypeException() {
+        super(Message.ERR_MSG_INVALID_INPUT_TYPE);
+    }
+
+    public InputTypeException(String message) {
+        super(message);
+    }
+}
diff --git a/me.smartstore/src/exception/NullArgumentException.java b/me.smartstore/src/exception/NullArgumentException.java
new file mode 100644
index 00000000..14349091
--- /dev/null
+++ b/me.smartstore/src/exception/NullArgumentException.java
@@ -0,0 +1,22 @@
+package exception;
+
+public class NullArgumentException extends RuntimeException {
+    public NullArgumentException() {
+    }
+
+    public NullArgumentException(String message) {
+        super(message);
+    }
+
+    public NullArgumentException(String message, Throwable cause) {
+        super(message, cause);
+    }
+
+    public NullArgumentException(Throwable cause) {
+        super(cause);
+    }
+
+    public NullArgumentException(String message, Throwable cause, boolean enableSuppression, boolean writableStackTrace) {
+        super(message, cause, enableSuppression, writableStackTrace);
+    }
+}
diff --git a/me.smartstore/src/group/Group.java b/me.smartstore/src/group/Group.java
new file mode 100644
index 00000000..a47dab3b
--- /dev/null
+++ b/me.smartstore/src/group/Group.java
@@ -0,0 +1,53 @@
+package group;
+
+import java.util.Objects;
+
+public class Group {
+    private Parameter parameter; //분류기준
+    private GroupType groupType; //분류한 그룹 타입
+
+    public Group() {
+    }
+
+    public Group(Parameter parameter, GroupType groupType) {
+        this.parameter = parameter;
+        this.groupType = groupType;
+    }
+
+    public Parameter getParameter() {
+        return parameter;
+    }
+
+    public void setParameter(Parameter parameter) {
+        this.parameter = parameter;
+    }
+
+    public GroupType getGroupType() {
+        return groupType;
+    }
+
+    public void setGroupType(GroupType groupType) {
+        this.groupType = groupType;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Group group = (Group) o;
+        return Objects.equals(parameter, group.parameter) && groupType == group.groupType;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(parameter, groupType);
+    }
+
+    @Override
+    public String toString() {
+        return "Group{" +
+                "parameter=" + parameter +
+                ", groupType=" + groupType +
+                '}';
+    }
+}
diff --git a/me.smartstore/src/group/GroupType.java b/me.smartstore/src/group/GroupType.java
new file mode 100644
index 00000000..d28d52f3
--- /dev/null
+++ b/me.smartstore/src/group/GroupType.java
@@ -0,0 +1,19 @@
+package group;
+
+public enum GroupType {
+    N("해당없음"), G("일반고객"), V("우수고객"), VV("최우수고객"),
+    NONE("해당없음"), GENERAL("일반고객"), VIP("우수고객"), VVIP("최우수고객");
+    String groupType = "";
+    GroupType(String groupType) {
+        this.groupType = groupType;
+    }
+
+
+    public GroupType replaceFullName(){
+        if(this == N) return NONE;
+        else if (this == G) return GENERAL;
+        else if (this == V) return VIP;
+        else if (this == VV) return VVIP;
+        return this;
+    }
+}
diff --git a/me.smartstore/src/group/Groups.java b/me.smartstore/src/group/Groups.java
new file mode 100644
index 00000000..6c395b45
--- /dev/null
+++ b/me.smartstore/src/group/Groups.java
@@ -0,0 +1,26 @@
+package group;
+
+import arrays.DArray;
+
+public class Groups extends DArray<Group> {
+    private static Groups allGroups;
+
+    public static Groups getInstance(){
+        if(allGroups == null){
+            allGroups = new Groups();
+            allGroups.add(new Group(new Parameter(), GroupType.NONE));
+        }
+        return allGroups;
+    }
+    private Groups(){}
+
+    public Group find(GroupType groupType){
+        for (int i = 0; i < allGroups.size; i++) {
+            if (allGroups.get(i).getGroupType() == groupType) {
+                return allGroups.get(i);
+            }
+        }
+        return  null;
+    }
+
+}
diff --git a/me.smartstore/src/group/Parameter.java b/me.smartstore/src/group/Parameter.java
new file mode 100644
index 00000000..537dfff0
--- /dev/null
+++ b/me.smartstore/src/group/Parameter.java
@@ -0,0 +1,53 @@
+package group;
+
+import java.util.Objects;
+
+public class Parameter {
+    private Integer minTime;
+    private Integer minPay;
+
+    public Parameter() {
+    }
+
+    public Parameter(Integer minTime, Integer minPay) {
+        this.minTime = minTime;
+        this.minPay = minPay;
+    }
+
+    public Integer getMinTime() {
+        return minTime;
+    }
+
+    public void setMinTime(Integer minTime) {
+        this.minTime = minTime;
+    }
+
+    public Integer getMinPay() {
+        return minPay;
+    }
+
+    public void setMinPay(Integer minPay) {
+        this.minPay = minPay;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        Parameter parameter = (Parameter) o;
+        return Objects.equals(minTime, parameter.minTime) && Objects.equals(minPay, parameter.minPay);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(minTime, minPay);
+    }
+
+    @Override
+    public String toString() {
+        return "Parameter{" +
+                "minTime=" + minTime +
+                ", minPay=" + minPay +
+                '}';
+    }
+}
diff --git a/me.smartstore/src/menu/CustomerMenu.java b/me.smartstore/src/menu/CustomerMenu.java
new file mode 100644
index 00000000..55acac1c
--- /dev/null
+++ b/me.smartstore/src/menu/CustomerMenu.java
@@ -0,0 +1,176 @@
+package menu;
+
+import customer.Customer;
+import customer.Customers;
+import exception.InputEndException;
+import exception.InputRangeException;
+import group.Groups;
+import util.Message;
+
+import static util.Message.END_MSG;
+
+public class CustomerMenu implements Menu{
+    private final Customers allCustomers = Customers.getInstance();
+    private final Groups allGroups = Groups.getInstance();
+    private static CustomerMenu customerMenu;
+
+    public static CustomerMenu getInstance(){
+        if(customerMenu == null){
+            customerMenu = new CustomerMenu();
+        }
+        return customerMenu;
+    }
+    private CustomerMenu(){}
+
+    @Override
+    public void manage() {
+        while (true) {
+            int choice = chooseMenu(new String[]{
+                    "Add Customer",
+                    "View Customer",
+                    "Update Customer",
+                    "Delete Customer",
+                    "Back"
+            });
+            if(choice == 1) addCustomer();
+            else if(choice == 2) viewCustomer();
+            else if(choice == 3) updateCustomer();
+            else if(choice == 4) deleteCustomer();
+            else break;
+        }
+
+    }
+
+
+    /**
+     * 고객 추가 메소드 end 입력시 종료
+     * */
+    public void addCustomer(){
+        while(true){
+            System.out.println("How many customers to input?");
+            try{
+                String num = nextLine(Message.END_MSG);
+                for(int i=0; i<Integer.parseInt(num); i++){
+                    System.out.printf("====== Customer %d Info. ====== \n", i+1);
+                    Customer customer = new Customer();
+                    addCustomerManage(customer);
+                    allCustomers.refresh();
+                }
+                break;
+            } catch (InputEndException e){
+                System.out.println(Message.ERR_MSG_INPUT_END);
+                break;
+            }
+        }
+    }
+
+    /**
+     * 고객 추가 메소드에서 호출 이름, 아이디, 시간, 돈중에 추가할 정보를 선택
+     * */
+    private void addCustomerManage(Customer customer) {
+        while (true) {
+            int choice = chooseMenu(new String[]{
+                    "Customer Name",
+                    "Customer ID",
+                    "Customer Spent Time",
+                    "Customer Total Pay",
+                    "Back"
+            });
+            if(choice == 1) addCustomerName(customer);
+            else if(choice == 2) addCustomerID(customer);
+            else if(choice == 3) addCustomerSpentTime(customer);
+            else if(choice == 4) addCustomerTotalPay(customer);
+            else break;
+        }
+    }
+    //이름 추가 end입력시 종료
+    private void addCustomerName(Customer customer) {
+        System.out.println("Input Customer's Name:");
+        try{
+            String name = nextLine(Message.END_MSG);
+            customer.setcName(name);
+        } catch (InputEndException e){
+            System.out.println(Message.ERR_MSG_INPUT_END);
+        }
+    }
+    //ID추가 end입력시 종료
+    private void addCustomerID(Customer customer) {
+        System.out.println("Input Customer's ID:");
+        try{
+            String id = nextLine(Message.END_MSG);
+            customer.setcId(id);
+        } catch (InputEndException e){
+            System.out.println(Message.ERR_MSG_INPUT_END);
+        }
+    }
+    //시간추가 end입력시 종료
+    private void addCustomerSpentTime(Customer customer) {
+        System.out.println("Input Customer's Spent Time:");
+        try{
+            String time = nextLine(Message.END_MSG);
+            customer.setTotalTime(Integer.parseInt(time));
+        } catch (InputEndException e){
+            System.out.println(Message.ERR_MSG_INPUT_END);
+        }
+    }
+    //pay추가 end입력시 종료
+    private void addCustomerTotalPay(Customer customer) {
+        System.out.println("Input Customer's Total Pay:");
+        try{
+            String pay = nextLine(Message.END_MSG);
+            customer.setTotalPay(Integer.parseInt(pay));
+        } catch (InputEndException e){
+            System.out.println(Message.ERR_MSG_INPUT_END);
+        }
+    }
+    /**
+     * 모든 고객의 정보를 출력
+     * */
+    public void viewCustomer(){
+        System.out.println("======= Customer Info. =======");
+        for(int i=0; i<allCustomers.size(); i++){
+            Customer customer = allCustomers.get(i);
+            System.out.println(String.format("No. %d => ", i+1)+ customer);
+        }
+    }
+    /**
+     * 고객을 선택하여 정보를 업데이트
+     * */
+    private void updateCustomer() {
+        try {
+            viewCustomer();
+            System.out.printf("Which customer ( 1 ~ %d )? ", allCustomers.size());
+            Integer index = scanner.nextInt();
+            scanner.nextLine(); //버퍼에 남아있는 엔터값 처리
+            if(index <= 0 || index > allCustomers.size()){
+                throw new InputRangeException();
+            }
+            Customer customer = allCustomers.get(index - 1);
+            addCustomerManage(customer);
+            allCustomers.refresh();
+        } catch (InputRangeException e){
+            System.out.println(Message.ERR_MSG_INVALID_INPUT_RANGE);
+        }
+    }
+
+    /**
+     * 고객 정보 삭제
+     * */
+    private void deleteCustomer() {
+        try {
+            viewCustomer();
+            System.out.printf("Which customer ( 1 ~ %d )? ", allCustomers.size());
+            Integer index = scanner.nextInt();
+            scanner.nextLine(); //버퍼에 남아있는 엔터값 처리
+            if(index <= 0 || index > allCustomers.size()){
+                throw new InputRangeException();
+            }
+            System.out.println(allCustomers.get(index - 1));
+            allCustomers.pop(index - 1);
+            viewCustomer();
+        } catch (InputRangeException e){
+            System.out.println(Message.ERR_MSG_INVALID_INPUT_RANGE);
+        }
+    }
+
+}
diff --git a/me.smartstore/src/menu/GroupMenu.java b/me.smartstore/src/menu/GroupMenu.java
new file mode 100644
index 00000000..382ba449
--- /dev/null
+++ b/me.smartstore/src/menu/GroupMenu.java
@@ -0,0 +1,182 @@
+package menu;
+
+import customer.Customers;
+import exception.InputEndException;
+import group.Group;
+import group.GroupType;
+import group.Groups;
+import group.Parameter;
+import util.Message;
+
+
+public class GroupMenu implements Menu{
+    private static GroupMenu groupMenu;
+    private final Customers allCustomers = Customers.getInstance();
+    private final Groups allGroups = Groups.getInstance();
+
+    public static GroupMenu getInstance(){
+        if(groupMenu == null){
+            groupMenu = new GroupMenu();
+        }
+        return groupMenu;
+    }
+    private GroupMenu(){}
+
+    @Override
+    public void manage() {
+        while (true) {
+            int choice = chooseMenu(new String[]{
+                    "Set Parameter",
+                    "View Parameter",
+                    "Update Parameter",
+                    "Back"
+            });
+            if(choice == 1) setParameter();
+            else if(choice == 2) viewParameter();
+            else if(choice == 3) updateParameter();
+            else break;
+        }
+    }
+    public GroupType chooseGroup(){
+        while(true){
+            try {
+                System.out.println("Which group (GENERAL (G), VIP (V), VVIP (VV))? ");
+                String choice = nextLine(Message.END_MSG);
+                // group (str) -> GroupType (enum)
+                // "VIP" -> GroupType.VIP
+                GroupType groupType = GroupType.valueOf(choice).replaceFullName(); // String -> enum
+                return groupType;
+            }catch (InputEndException e){
+                System.out.println(Message.ERR_MSG_INPUT_END);
+                return null;
+            } catch (IllegalArgumentException e){
+                System.out.println(Message.ERR_MSG_INVALID_INPUT_RANGE);
+            }
+        }
+    }
+
+    /**
+     * groupType의 시간과 돈울 입력받은 값으로 설정해준다.
+     * */
+    public void setParameter(){
+        while (true){
+            GroupType groupType = chooseGroup();
+            if(groupType == null){
+                System.out.println("break란다");
+                break;
+            }
+            //GroupType에 해당하는 group객체를 찾아야함
+            Group group = allGroups.find(groupType);
+            if (group != null && group.getParameter() != null) { // group.getParameter()이 null이 아니면 이미 초기화됨
+                System.out.println("\n" + group.getGroupType() + " group already exists.");
+                System.out.println("\n" + group);
+            } else {
+                group = new Group(new Parameter(), groupType);
+                allGroups.add(group);
+                Setmanage(group);
+                allCustomers.refresh(); // 파라미터가 변경되었거나 추가되는 경우, 고객 분류를 다시 해야함
+            }
+        }
+    }
+    /**
+     * 어떤 파라미터를 추가할건지 선택
+     * */
+    public void Setmanage(Group group) {
+        while (true) {
+            int choice = chooseMenu(new String[]{
+                    "Minimum Spent Time",
+                    "Minimum Total Pay",
+                    "Back"
+            });
+            if(choice == 1) setMinTime(group);
+            else if(choice == 2) setMinPay(group);
+            else break;
+        }
+    }
+
+    /**
+     * groupType의 해당하는 파라미터값을 출력함
+     * */
+    public void viewParameter(){
+        while(true){
+            GroupType groupType = chooseGroup();
+            if(groupType == null){
+                break;
+            }
+            //GroupType에 해당하는 group객체를 찾아야함
+            Group group = allGroups.find(groupType);
+            System.out.println(groupType);
+            System.out.println(group.getParameter());
+        }
+    }
+
+    /**
+     * groupType의 파라미터값을 수정함
+     * */
+    public void updateParameter(){
+        while(true){
+            GroupType groupType = chooseGroup();
+            if(groupType == null){
+                break;
+            }
+            //GroupType에 해당하는 group객체를 찾아야함
+            Group group = allGroups.find(groupType);
+            System.out.println(groupType);
+            System.out.println(group.getParameter());
+            updateParameterManage(group);
+        }
+    }
+    /**
+     * 어떤 파라미터 값을 수정할 것인지 선택
+     * */
+    public void updateParameterManage(Group group){
+        while (true) {
+            int choice = chooseMenu(new String[]{
+                    "Minimum Spent Time",
+                    "Minimum Total Pay",
+                    "Back"
+            });
+            if(choice == 1) setMinTime(group);
+            else if(choice == 2) setMinPay(group);
+            else break;
+        }
+    }
+
+    // 시간을 수정 end입력시 종료
+    public void setMinTime(Group group){
+        while (true){
+            try {
+                System.out.printf("Input Minimum Spent Time:");
+                String spentTime = nextLine(Message.END_MSG);
+                Parameter parameter = group.getParameter();
+                parameter.setMinTime(Integer.parseInt(spentTime));
+                group.setParameter(parameter);
+                System.out.println(group.getParameter());
+                allCustomers.refresh();// 파라미터가 변경되었거나 추가되는 경우, 고객 분류를 다시 해야함
+                break;
+            } catch (InputEndException e){
+                System.out.println(Message.ERR_MSG_INPUT_END);
+                break;
+            }
+        }
+    }
+    //돈을 수정 end입력시 종료
+    public void setMinPay(Group group){
+        while (true){
+            try {
+                System.out.printf("Input Minimum Total Pay:");
+                String totalPay = nextLine(Message.END_MSG);
+                Parameter parameter = group.getParameter();
+                parameter.setMinPay(Integer.parseInt(totalPay));
+                group.setParameter(parameter);
+                System.out.println(group.getParameter());
+                allCustomers.refresh();// 파라미터가 변경되었거나 추가되는 경우, 고객 분류를 다시 해야함
+                break;
+            }catch (InputEndException e){
+                System.out.println(Message.ERR_MSG_INPUT_END);
+                break;
+            }
+        }
+    }
+}
+
diff --git a/me.smartstore/src/menu/MainMenu.java b/me.smartstore/src/menu/MainMenu.java
new file mode 100644
index 00000000..a5ea845d
--- /dev/null
+++ b/me.smartstore/src/menu/MainMenu.java
@@ -0,0 +1,34 @@
+package menu;
+
+public class MainMenu implements Menu{
+    private final CustomerMenu customerMenu = CustomerMenu.getInstance();
+    private final GroupMenu groupMenu = GroupMenu.getInstance();
+    private final SummaryMenu summaryMenu = SummaryMenu.getInstance();
+    private static MainMenu mainMenu;
+
+    public static MainMenu getInstance(){
+        if(mainMenu == null){
+            mainMenu = new MainMenu();
+        }
+        return mainMenu;
+    }
+    private MainMenu(){}
+
+    @Override
+    public void manage() {
+        while(true){ //프로그램 실행 while
+            int choice = mainMenu.chooseMenu(new String[] {
+                    "Parameter",
+                    "Customer Data",
+                    "Classification Summary",
+                    "Quit"
+            });
+            if(choice == 1) groupMenu.manage();
+            else if(choice == 2) customerMenu.manage();
+            else if(choice == 3) summaryMenu.manage();
+            else {System.out.println("Program Finish"); break;}
+        }
+    }
+
+
+}
diff --git a/me.smartstore/src/menu/Menu.java b/me.smartstore/src/menu/Menu.java
new file mode 100644
index 00000000..8af64754
--- /dev/null
+++ b/me.smartstore/src/menu/Menu.java
@@ -0,0 +1,48 @@
+package menu;
+
+import exception.InputEndException;
+import exception.InputRangeException;
+import group.Groups;
+import util.Message;
+
+import java.util.Locale;
+import java.util.Scanner;
+
+public interface Menu {
+    public Scanner scanner = new Scanner(System.in);
+
+    default String nextLine(){ //String
+        return scanner.nextLine().toUpperCase(); //대소문자 구분 없애기 위해
+    }
+    default String nextLine(String end) {
+        System.out.println("** Press 'end', if you want to exit! **");
+        String str = scanner.nextLine().toUpperCase();
+        if (str.equals(end)) throw new InputEndException();
+        return str;
+    }
+    /**public String nextLine(){ //Integer
+        String str = scanner.nextLine().toUpperCase(); //대소문자 구분 없애기 위해
+        return str;
+    }*/
+    default int chooseMenu(String[] menus){
+        while(true) { //예외 복구 while
+            try {
+                System.out.println("===============================");
+                for (int i = 0; i < menus.length; i++) {
+                    System.out.printf(" %d. %s\n", i + 1, menus[i]);
+                }
+                System.out.println("===============================");
+                System.out.print("Choose One: ");
+                int choice = Integer.parseInt(nextLine());
+                if (choice >= 1 && choice <= menus.length) return choice;
+                throw new InputRangeException(); // choice 가 범위에 벗어남
+            } catch (NumberFormatException e){
+                System.out.println(Message.ERR_MSG_INVALID_INPUT_FORMAT);
+            } catch (InputRangeException e){
+                System.out.println(Message.ERR_MSG_INVALID_INPUT_RANGE);
+            }
+        }
+    }
+    void manage(); //각 서브메뉴들을 관리하는 함수
+
+}
diff --git a/me.smartstore/src/menu/SummaryMenu.java b/me.smartstore/src/menu/SummaryMenu.java
new file mode 100644
index 00000000..cf0b7ab1
--- /dev/null
+++ b/me.smartstore/src/menu/SummaryMenu.java
@@ -0,0 +1,236 @@
+package menu;
+
+import customer.Customer;
+import customer.Customers;
+import exception.InputEndException;
+import exception.InputRangeException;
+import group.Group;
+import group.GroupType;
+import group.Groups;
+import group.Parameter;
+import util.Message;
+
+import java.lang.reflect.Array;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Comparator;
+
+import static group.GroupType.*;
+
+public class SummaryMenu implements Menu{
+    private static SummaryMenu summaryMenu;
+    private final Customers allCustomers = Customers.getInstance();
+    private final Groups allGroups = Groups.getInstance();
+
+    public static SummaryMenu getInstance(){
+        if(summaryMenu == null){
+            summaryMenu = new SummaryMenu();
+        }
+        return summaryMenu;
+    }
+    private SummaryMenu(){}
+
+    @Override
+    public void manage() {
+        while (true) { //서브 메뉴 페이지를 유지하기 위한 while
+            int choice = chooseMenu(new String[]{
+                    "Summary",
+                    "Summary (Sorted By Name)",
+                    "Summary (Sorted By Spent Time)",
+                    "Summary (Sorted By Total Payment)",
+                    "Back"
+            });
+            if(choice == 1) summary(getCustomer());
+            else if(choice == 2) summarySortByName(getCustomer());
+            else if(choice == 3) summarySortBySpentTime(getCustomer());
+            else if(choice == 4) summarySortByTotalPay(getCustomer());
+            else break;
+        }
+    }
+    /**
+     * groupType별로 출력
+     * */
+    public void summary(Customer[] customers){
+        Parameter parameter = null;
+        Group group = null;
+        GroupType[] groupType = {NONE, GENERAL, VIP, VVIP};
+        for(GroupType type: groupType){
+            for(int i=0; i<allGroups.size(); i++){
+                if(allGroups.get(i).getGroupType() == type){
+                    group = allGroups.get(i);
+                    parameter = group.getParameter();
+                }
+            }
+            System.out.println("==============================");
+            if(parameter != null){
+                System.out.println(type + ": " + type.name() + "( Time : " + parameter.getMinTime() + ", Pay : "+ parameter.getMinPay() + " )");
+            }
+            else{
+                System.out.println(type + ": " + type.name() + "( Time : null  Pay : null )");
+            }
+            System.out.println("==============================");
+
+            if(group != null) {
+                System.out.println("group is not null");
+                for (int i = 0; i < customers.length; i++) {
+                    if(customers[i].getGroup().getGroupType() == type){
+                        System.out.println(String.format("No. %d => ", i + 1) + customers[i]);
+                    }
+                }
+            }
+            else{
+                System.out.println("Null.");
+            }
+            System.out.println("==============================");
+            System.out.println("");
+        }
+    }
+
+    /**
+     * 이름순으로 정렬 내림차순 올림차순은 사용자가 설정
+     * */
+    public void summarySortByName(Customer[] customers){
+        while(true){
+            try {
+                System.out.println("Which order (ASCENDING (A), DESCENDING (D))?");
+                String choice = nextLine(Message.END_MSG);
+                int flag = 0;
+                if(!choice.equals("A") && !choice.equals("D")){
+                    throw new InputRangeException();
+                }
+                if(choice.equals("A")){
+                    flag = 1; //오름차순 정렬
+                }
+                else {
+                    flag = -1; //내림차순 정렬
+                }
+                summary(sortCustomerByName(flag, customers)); //정렬된것 바탕으로 출력
+            } catch (InputEndException e) {
+                System.out.println(Message.ERR_MSG_INPUT_END);
+                break;
+            } catch (InputRangeException e){
+                System.out.println(Message.ERR_MSG_INVALID_INPUT_RANGE);
+            }
+        }
+    }
+    //오름차순 혹은 내림차순으로 정렬
+    public Customer[] sortCustomerByName(int flag, Customer[] customers){
+        if(flag == 1){
+            Arrays.sort(customers);
+        }
+        else{
+            Arrays.sort(customers, Collections.reverseOrder());
+        }
+        return customers;
+    }
+
+    //customer을 배열로 반환
+    public Customer[] getCustomer(){
+        Customer[] customers = new Customer[allCustomers.size()];
+        for (int i=0; i< allCustomers.size(); i++){
+            customers[i] = allCustomers.get(i);
+        }
+        return customers;
+    }
+    /**
+     * 시간으로 정렬
+     * */
+    public void summarySortBySpentTime(Customer[] customers){
+        while(true){
+            try {
+                System.out.println("Which order (ASCENDING (A), DESCENDING (D))?");
+                String choice = nextLine(Message.END_MSG);
+                int flag = 0;
+                if(!choice.equals("A") && !choice.equals("D")){
+                    throw new InputRangeException();
+                }
+                if(choice.equals("A")){
+                    flag = 1;
+                }
+                else {
+                    flag = -1;
+                }
+                summary(sortCustomerByTime(flag, customers));
+            } catch (InputEndException e) {
+                System.out.println(Message.ERR_MSG_INPUT_END);
+                break;
+            } catch (InputRangeException e){
+                System.out.println(Message.ERR_MSG_INVALID_INPUT_RANGE);
+            }
+        }
+    }
+
+    //시간으로 오름차순 혹은 내림차순으로 정렬
+    public Customer[] sortCustomerByTime(int flag, Customer[] customers){
+        if(flag == 1){
+            Arrays.sort(customers, new Comparator<Customer>() {
+                @Override
+                public int compare(Customer o1, Customer o2) {
+                    return o1.getTotalTime() - o2.getTotalTime();
+                }
+            });
+        }
+        else{
+            Arrays.sort(customers, new Comparator<Customer>() {
+                @Override
+                public int compare(Customer o1, Customer o2) {
+                    return o2.getTotalTime() - o1.getTotalTime();
+                }
+            });
+        }
+        return customers;
+    }
+
+    /**
+     * 페이순으로 정렬
+     * */
+    public void summarySortByTotalPay(Customer[] customers){
+        while(true){
+            try {
+                System.out.println("Which order (ASCENDING (A), DESCENDING (D))?");
+                String choice = nextLine(Message.END_MSG);
+                int flag = 0;
+                if(!choice.equals("A") && !choice.equals("D")){
+                    throw new InputRangeException();
+                }
+                if(choice.equals("A")){
+                    flag = 1;
+                }
+                else {
+                    flag = -1;
+                }
+                summary(sortCustomerByPay(flag, customers));
+            } catch (InputEndException e) {
+                System.out.println(Message.ERR_MSG_INPUT_END);
+                break;
+            } catch (InputRangeException e){
+                System.out.println(Message.ERR_MSG_INVALID_INPUT_RANGE);
+            }
+        }
+    }
+    //페이를 오름차순 혹은 내림차순으로 정렬
+    public Customer[] sortCustomerByPay(int flag, Customer[] customers){
+        if(flag == 1){
+            Arrays.sort(customers, new Comparator<Customer>() {
+                @Override
+                public int compare(Customer o1, Customer o2) {
+                    return o1.getTotalPay() - o2.getTotalPay();
+                }
+            });
+        }
+        else{
+            Arrays.sort(customers, new Comparator<Customer>() {
+                @Override
+                public int compare(Customer o1, Customer o2) {
+                    return o2.getTotalPay() - o1.getTotalPay();
+                }
+            });
+        }
+        return customers;
+    }
+
+
+
+
+}
diff --git a/me.smartstore/src/util/Message.java b/me.smartstore/src/util/Message.java
new file mode 100644
index 00000000..7d33cb17
--- /dev/null
+++ b/me.smartstore/src/util/Message.java
@@ -0,0 +1,13 @@
+package util;
+
+public interface Message {
+    String ERR_MSG_INVALID_ARR_EMPTY = "No Customers. Please input one first.";
+    String ERR_MSG_NULL_ARR_ELEMENT = "Elements in Array has null. Array can't be sorted.";
+    String ERR_MSG_INVALID_INPUT_NULL = "Null Input. Please input something.";
+    String ERR_MSG_INVALID_INPUT_EMPTY = "Empty Input. Please input something.";
+    String ERR_MSG_INVALID_INPUT_RANGE = "Invalid Input. Please try again.";
+    String ERR_MSG_INVALID_INPUT_TYPE = "Invalid Type for Input. Please try again.";
+    String ERR_MSG_INVALID_INPUT_FORMAT = "Invalid Format for Input. Please try again.";
+    String ERR_MSG_INPUT_END = "END is pressed. Exit this menu.";
+    String END_MSG = "END";
+}