diff --git a/Api/src/main/java/edu/inventorym/Api.java b/Api/src/main/java/edu/inventorym/Api.java
index c75b02c..069fe59 100644
--- a/Api/src/main/java/edu/inventorym/Api.java
+++ b/Api/src/main/java/edu/inventorym/Api.java
@@ -34,8 +34,6 @@ public interface Api {
          * is not already in the inventory before adding
          */
 
-        InventoryManager.getInstance().getArtPieceTypes().forEach(System.out::println);
-
         /* Add Inventory */
 
         InventoryManager.getInstance().add(make(new Drawing()));
@@ -45,17 +43,24 @@ public interface Api {
         InventoryManager.getInstance().add(make(new Sculpture()));
         InventoryManager.getInstance().add(make(new Sculpture()));
 
+        /* Add Customer */
+        //CustomerManager.getInstance().add(new Customer("Kate", "Demsey", "310-676-4844", "kate@museum.com"));
+        //CustomerManager.getInstance().add(new Customer("Jim", "Gumbly", "203-676-4844", "jim@homedeco.com"));
+        CustomerManager.getInstance().load();
         /*
          * 2. Remove art object from the inventory
          */
         InventoryManager imgr = InventoryManager.getInstance();
-        InventoryPiece art = imgr.find("####");
-        imgr.Remove(art);
+        System.out.println(String.format("Art Pieces in INVENTORY: count %d", imgr.INVENTORY.size()));
+        InventoryPiece art = imgr.INVENTORY.getLast();
+        InventoryPiece piece = imgr.find(art.getId());
+        imgr.Remove(piece);
+        System.out.println(String.format("Removed 1 Art Pieces from INVENTORY: count %d", imgr.INVENTORY.size()));
         /*
          * 3. Return a list of all art objects from inventory
          */
         CustomerManager cmgr = CustomerManager.getInstance();
-        Customer customer = cmgr.findByEmail("kate@it.com");
+        Customer customer = cmgr.findByEmail("kate@museum.com");
         InventoryList customerCart = new InventoryList();
 
         TransactionManager tmgr = TransactionManager.getInstance();
diff --git a/Api/src/resources/db/customers.json b/Api/src/resources/db/customers.json
new file mode 100644
index 0000000..b95a5e3
--- /dev/null
+++ b/Api/src/resources/db/customers.json
@@ -0,0 +1,16 @@
+[
+    {
+        "email": "kate@museum.com",
+        "id": "1039445606",
+        "nameFirst": "Kate",
+        "nameLast": "Demsey",
+        "phone": "310-676-4844"
+    },
+    {
+        "email": "jim@homedeco.com",
+        "id": "4312148107",
+        "nameFirst": "Jim",
+        "nameLast": "Gumbly",
+        "phone": "203-676-4844"
+    }
+]
\ No newline at end of file
diff --git a/Model/src/main/java/edu/inventorym/model/Customer.java b/Model/src/main/java/edu/inventorym/model/Customer.java
index e5fc45e..9e4be81 100644
--- a/Model/src/main/java/edu/inventorym/model/Customer.java
+++ b/Model/src/main/java/edu/inventorym/model/Customer.java
@@ -20,10 +20,11 @@ public class Customer {
         this.nameLast = nameLast;
         this.phone = phone;
         this.email = email;
+        this.id = DataRepository.generateRandom10DigitID(); 
         this.updated = ZonedDateTime.now();
     }
 
-    public Customer(){}
+    protected Customer(){}
 
     public String getEmail() {
         return email;
diff --git a/Model/src/main/java/edu/inventorym/model/CustomerManager.java b/Model/src/main/java/edu/inventorym/model/CustomerManager.java
index f1b70be..a6aa80f 100644
--- a/Model/src/main/java/edu/inventorym/model/CustomerManager.java
+++ b/Model/src/main/java/edu/inventorym/model/CustomerManager.java
@@ -4,6 +4,8 @@
 */
 package edu.inventorym.model;
 
+import java.io.IOException;
+
 public class CustomerManager {
     
     final static CustomerManager INSTANCE = new CustomerManager();
@@ -28,6 +30,29 @@ public class CustomerManager {
     }
 
     public Customer findByEmail(String email){
+        for (Customer c : CUSTOMERS) {
+            if (email.equalsIgnoreCase(c.getEmail())) {
+                return c;
+            }
+        } 
         return null;
     }
+    
+    public void save() {
+        try {
+            DataRepository.write(this);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void load(){
+        try {
+            DataRepository.read(this);
+        } catch (IOException e) {
+            e.printStackTrace();
+        } catch(Exception e){
+            e.printStackTrace();
+        }
+     }
 }
diff --git a/Model/src/main/java/edu/inventorym/model/DataRepository.java b/Model/src/main/java/edu/inventorym/model/DataRepository.java
index b3f5888..82867d7 100644
--- a/Model/src/main/java/edu/inventorym/model/DataRepository.java
+++ b/Model/src/main/java/edu/inventorym/model/DataRepository.java
@@ -4,9 +4,18 @@
 */
 package edu.inventorym.model;
 
+import java.io.BufferedReader;
+import java.io.BufferedWriter;
+import java.io.FileReader;
+import java.io.FileWriter;
 import java.io.IOException;
 import java.io.StringReader;
 import java.math.BigInteger;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.OpenOption;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.security.SecureRandom;
 import java.util.ArrayList;
 import java.util.Base64;
@@ -25,7 +34,7 @@ public class DataRepository {
         return INSTANCE;
     }
 
-        final public static String generateRandomID(int byteLength) {
+    final public static String generateRandomID(int byteLength) {
         SecureRandom secureRandom = new SecureRandom();
         byte[] bytes = new byte[byteLength];
         secureRandom.nextBytes(bytes);
@@ -41,7 +50,7 @@ public class DataRepository {
         BigInteger val2 = randomCountLength.add(val1);
         return String.format("%010d", val2);
     }
-    
+
     public static void WalkFileSystemTree(final InventoryManager manager) throws IOException {
     }
 
@@ -51,84 +60,117 @@ public class DataRepository {
     public static void WalkFileSystemTree(final TransactionManager manager) throws IOException {
     }
 
-    
-    static void serialize_deserialize(){
+    static void serialize_deserialize() {
         String jsonResponse = "";
-        try{
-        // Deserialize the JSON string to a Java RpcResponse object
-        Jsonb jsonb = JsonbBuilder.create();
-        jsonResponse = jsonb.toJson((InventoryPiece)new Drawing());
+        try {
+            // Deserialize the JSON string to a Java RpcResponse object
+            Jsonb jsonb = JsonbBuilder.create();
+            jsonResponse = jsonb.toJson((InventoryPiece) new Drawing());
 
-        System.out.println("json string: " + jsonResponse);
+            System.out.println("json string: " + jsonResponse);
 
+            InventoryPiece response = jsonb.fromJson(jsonResponse, Drawing.class);
 
-        InventoryPiece response = jsonb.fromJson(jsonResponse, Drawing.class);
+            System.out.println("Result: " + response);
+            System.out.println("ID: " + response.getId());
 
-        System.out.println("Result: " + response);
-        System.out.println("ID: " + response.getId());
-
-        }catch(Exception e){
-            e.printStackTrace();
-        }
-
-        try{
-        // Configure pretty-printing and other settings
-        JsonbConfig config = new JsonbConfig()
-                .withFormatting(true); // Enable pretty-printing
-        Jsonb jsonb = JsonbBuilder.create(config);
-
-        // Serialize using the custom configuration
-        String prettyJsonString = jsonb.toJson(new Drawing());
-
-        System.out.println("json string: " + prettyJsonString);
-
-        }catch(Exception e){
+        } catch (Exception e) {
             e.printStackTrace();
         }
 
         try {
-             List<Drawing> rpcs = new ArrayList<Drawing>();
-              rpcs.add(new Drawing());
-              rpcs.add(new Drawing());
-              rpcs.add(new Drawing());
+            // Configure pretty-printing and other settings
+            JsonbConfig config = new JsonbConfig()
+                    .withFormatting(true); // Enable pretty-printing
+            Jsonb jsonb = JsonbBuilder.create(config);
 
-        // Create Jsonb and serialize
-        Jsonb jsonb = JsonbBuilder.create();
-        String result = jsonb.toJson(rpcs);
+            // Serialize using the custom configuration
+            String prettyJsonString = jsonb.toJson(new Drawing());
 
-        
-            // Deserialize back
-            rpcs = jsonb.fromJson(result, 
-            new ArrayList<Drawing>() {}
-            .getClass()
-            .getGenericSuperclass());
-        
-         System.out.println(  rpcs );
+            System.out.println("json string: " + prettyJsonString);
 
         } catch (Exception e) {
             e.printStackTrace();
+        }
+
+        try {
+            List<Drawing> rpcs = new ArrayList<Drawing>();
+            rpcs.add(new Drawing());
+            rpcs.add(new Drawing());
+            rpcs.add(new Drawing());
+
+            // Create Jsonb and serialize
+            Jsonb jsonb = JsonbBuilder.create();
+            String result = jsonb.toJson(rpcs);
+
+            // Deserialize back
+            rpcs = jsonb.fromJson(result,
+                    new ArrayList<Drawing>() {
+                    }
+                            .getClass()
+                            .getGenericSuperclass());
+
+            System.out.println(rpcs);
+
+        } catch (Exception e) {
+            e.printStackTrace();
+        }
+
+    }
+
+    public static <T> List<T> mapJsonToObjectList(String body, Class<T> baseClass) throws Exception {
+        try (var reader = Json.createReader(new StringReader(body));
+                Jsonb jsonb = JsonbBuilder.create()) {
+            JsonArray jsonArray = reader.readArray();
+
+            return jsonArray.stream()
+                    .map(jsonValue -> jsonb.fromJson(jsonValue.toString(), baseClass))
+                    .toList();
         } 
-
     }
 
-    public static <T> List<T> mapJsonToObjectList(String body, Class<T> baseClass) {
-    try (var reader = Json.createReader(new StringReader(body));
-            Jsonb jsonb = JsonbBuilder.create()){
-        JsonArray jsonArray = reader.readArray();
+    static void write(CustomerManager mgr) throws IOException{
+        JsonbConfig config = new JsonbConfig()
+                    .withFormatting(true); // Enable pretty-printing
+        Jsonb jsonb = JsonbBuilder.create(config);
+        String result = jsonb.toJson(mgr.CUSTOMERS);
 
-        return jsonArray.stream()
-                .map(jsonValue -> jsonb.fromJson(jsonValue.toString(), baseClass))
-                .toList();
-    } catch (Exception e) {
-        return (List<T>) new ArrayList<Drawing>();
+        
+        String dataRoot = getRepositoryConfig.getPath();
+        dataRoot = dataRoot + "/customers.json";
+        Path path = Paths.get(dataRoot);
+        try (BufferedWriter writer = Files.newBufferedWriter(path, StandardCharsets.UTF_8)) {
+            writer.write(result);
+            writer.flush();
+        }
+        
     }
+
+    public static void read(CustomerManager customerManager) throws IOException, Exception {
+        String dataRoot = getRepositoryConfig.getPath();
+        dataRoot = dataRoot + "/customers.json";
+        Path path = Paths.get(dataRoot);
+        String result;
+        try (BufferedReader in = new BufferedReader(new FileReader(path.toFile(), StandardCharsets.UTF_8))){
+            result = in.readAllAsString();
+        }
+
+       List<Customer> customers = mapJsonToObjectList(result, Customer.class);
+/*         Jsonb jsonb = JsonbBuilder.create();
+        CustomerList customers = jsonb.fromJson(result, new CustomerList() { }
+                            .getClass()
+                            .getGenericSuperclass()); */
+        customerManager.CUSTOMERS.clear();
+        customerManager.CUSTOMERS.addAll(customers);
     }
-    
+
     public final static class getRepositoryConfig {
         public final static String getPath() {
             String home = System.getenv("HOME") != null ? System.getenv("HOME")
                     : System.getenv("HOMEDRIVE") + System.getenv("HOMEPATH");
-            return home.replace('\\', '/') + "/workspace/reservationsystem/src/resources/db";
+            return home.replace('\\', '/') + "/workspace/inventorym/Api/src/resources/db";
         }
     }
+
+
 }
diff --git a/Model/src/main/java/edu/inventorym/model/Drawing.java b/Model/src/main/java/edu/inventorym/model/Drawing.java
index ce8c45d..5deb6fb 100644
--- a/Model/src/main/java/edu/inventorym/model/Drawing.java
+++ b/Model/src/main/java/edu/inventorym/model/Drawing.java
@@ -11,6 +11,12 @@ public class Drawing extends InventoryPiece {
     public String category;
 
     public Drawing() {
-        super(InventoryType.DRAWING);
+        super();
     }
+
+    @Override
+    public float computePrice() {
+        return price;
+    }
+    
 }
diff --git a/Model/src/main/java/edu/inventorym/model/InventoryManager.java b/Model/src/main/java/edu/inventorym/model/InventoryManager.java
index 087eb7f..b0457a9 100644
--- a/Model/src/main/java/edu/inventorym/model/InventoryManager.java
+++ b/Model/src/main/java/edu/inventorym/model/InventoryManager.java
@@ -21,15 +21,17 @@ public class InventoryManager {
     private InventoryManager() {
     }
 
-    public Set<InventoryType> getArtPieceTypes() {
-        return EnumSet.allOf(InventoryType.class);
-    }
-
     public void add(InventoryPiece iPiece) {
         INVENTORY.add(iPiece);
     }
 
     public InventoryPiece find(String id) {
+        for (InventoryPiece iv : INVENTORY) {
+            if (iv.getId() == id) {
+                return iv;
+            }
+        }
+        
         return null;
     }
 
@@ -40,7 +42,7 @@ public class InventoryManager {
     public void save() {
     }
 
-    public void loadAll(){
+    public void loadAll() {
         try {
             DataRepository.WalkFileSystemTree(INSTANCE);
         } catch (IOException e) {
@@ -49,11 +51,9 @@ public class InventoryManager {
         }
     }
 
-    public void Remove(InventoryPiece iPiece) {
-       
-        //int i = find(iPiece);
-        //INVENTORY.remove(i)
-       //*** multiple quantiies of iPiece */
+    public InventoryPiece Remove(InventoryPiece iPiece) {
+        int i = INVENTORY.indexOf(iPiece);        
+        return INVENTORY.remove(i);
     };
 
 }
diff --git a/Model/src/main/java/edu/inventorym/model/InventoryPiece.java b/Model/src/main/java/edu/inventorym/model/InventoryPiece.java
index 7e28c49..29f5750 100644
--- a/Model/src/main/java/edu/inventorym/model/InventoryPiece.java
+++ b/Model/src/main/java/edu/inventorym/model/InventoryPiece.java
@@ -15,7 +15,7 @@ public abstract class InventoryPiece {
     public float price;
     public ZonedDateTime created;
     public String title;
-
+    
     /**
      * max 500 characters
      */
@@ -23,23 +23,14 @@ public abstract class InventoryPiece {
 
     public String Author;
 
-    InventoryType iventoryType;
-
-    public InventoryPiece(InventoryType iventoryType) {
-        this.iventoryType = iventoryType;
-        this.created = ZonedDateTime.now();
-        this.id = DataRepository.generateRandom10DigitID();   
-    }
-
     public InventoryPiece() {
-    }
-
-    public Boolean isArt(InventoryPiece piece) {
-        return false;
+        this.created = ZonedDateTime.now();
+        this.id = DataRepository.generateRandom10DigitID();
+        this.price = 10.99F;   
     }
 
     public String getType() {
-        return this.iventoryType.toString();
+        return  this.getClass().getSimpleName().toUpperCase();
     };
 
     public String getId() {
@@ -89,4 +80,6 @@ public abstract class InventoryPiece {
     public void setAuthor(String author) {
         Author = author;
     }
+
+    public abstract float computePrice();
 }
diff --git a/Model/src/main/java/edu/inventorym/model/InventoryType.java b/Model/src/main/java/edu/inventorym/model/InventoryType.java
deleted file mode 100644
index 107674a..0000000
--- a/Model/src/main/java/edu/inventorym/model/InventoryType.java
+++ /dev/null
@@ -1,9 +0,0 @@
-/**
- * license: GPLv3
- edu.inventorym
-*/
-package edu.inventorym.model;
-
-public enum InventoryType {
-    PAINTING, DRAWING, PRINT, SCULPTURE
-}
diff --git a/Model/src/main/java/edu/inventorym/model/Painting.java b/Model/src/main/java/edu/inventorym/model/Painting.java
index 2c75e79..9f816d6 100644
--- a/Model/src/main/java/edu/inventorym/model/Painting.java
+++ b/Model/src/main/java/edu/inventorym/model/Painting.java
@@ -5,14 +5,77 @@
 package edu.inventorym.model;
 
 public class Painting extends InventoryPiece {
-    int height;
+
+int height;
     int width;
     String style;
     String technique;
     String category;
 
-    public Painting (){
-        super(InventoryType.PAINTING);
+    public Painting(int height, int width) {
+        super();
+        this.height = height;
+        this.width = width;
+    }
+    public Painting() {
+        super();
     }
 
+    public int getHeight() {
+        return height;
+    }
+
+    public void setHeight(int height) {
+        this.height = height;
+    }
+
+    public int getWidth() {
+        return width;
+    }
+
+    public void setWidth(int width) {
+        this.width = width;
+    }
+
+    public String getStyle() {
+        return style;
+    }
+
+    public void setStyle(String style) {
+        this.style = style;
+    }
+
+    public String getTechnique() {
+        return technique;
+    }
+
+    public void setTechnique(String technique) {
+        this.technique = technique;
+    }
+
+    public String getCategory() {
+        return category;
+    }
+
+    public void setCategory(String category) {
+        this.category = category;
+    }
+    
+    @Override
+    public float computePrice() {
+
+        int sqarea = height * width;
+        float additional = 0;
+        if (sqarea < 100) {
+            additional = 5.99F;
+        }
+        if (sqarea > 100 && sqarea < 300) {
+            additional = 10.99F;
+        }
+        if (sqarea > 300) {
+            additional = 15.99F;
+        }
+        return price + additional;
+
+    }
 }
diff --git a/Model/src/main/java/edu/inventorym/model/Print.java b/Model/src/main/java/edu/inventorym/model/Print.java
index 1c07a5f..9aa3fc0 100644
--- a/Model/src/main/java/edu/inventorym/model/Print.java
+++ b/Model/src/main/java/edu/inventorym/model/Print.java
@@ -10,7 +10,7 @@ public class Print extends InventoryPiece {
     String category;
 
     public Print(){
-        super(InventoryType.PRINT); 
+        super(); 
     }
 
     public Print(String openEditionType, String category) {
@@ -33,4 +33,9 @@ public class Print extends InventoryPiece {
     public void setCategory(String category) {
         this.category = category;
     }
+
+    @Override
+    public float computePrice() {
+        return price;
+    }
 }
diff --git a/Model/src/main/java/edu/inventorym/model/Sculpture.java b/Model/src/main/java/edu/inventorym/model/Sculpture.java
index 2b12ea6..9ee0448 100644
--- a/Model/src/main/java/edu/inventorym/model/Sculpture.java
+++ b/Model/src/main/java/edu/inventorym/model/Sculpture.java
@@ -9,8 +9,33 @@ public class Sculpture extends InventoryPiece {
     String material;
     float weight;
 
-    public Sculpture (){
-        super(InventoryType.SCULPTURE);
+    public Sculpture(float weight) {
+        super();
+        this.weight = weight;
     }
 
+    public Sculpture() {
+        super();
+    }
+
+    public String getMaterial() {
+        return material;
+    }
+
+    public void setMaterial(String material) {
+        this.material = material;
+    }
+
+    public float getWeight() {
+        return weight;
+    }
+
+    public void setWeight(float weight) {
+        this.weight = weight;
+    }
+
+    @Override
+    public float computePrice() {
+        return price + (weight * 0.20F);
+    }
 }
diff --git a/Model/src/main/java/edu/inventorym/model/Transaction.java b/Model/src/main/java/edu/inventorym/model/Transaction.java
index 91069ff..277654b 100644
--- a/Model/src/main/java/edu/inventorym/model/Transaction.java
+++ b/Model/src/main/java/edu/inventorym/model/Transaction.java
@@ -15,6 +15,7 @@ public class Transaction {
     String customerId;
     Address shipToAddress;
     InventoryList customerInventoryList;
+    float totalPrice = 0.0F;
     JsonArray attributes;
 
     public Transaction() {
@@ -33,6 +34,38 @@ public class Transaction {
         return created;
     }
 
+    public String getCustomerId() {
+        return customerId;
+    }
+
+    public Address getShipToAddress() {
+        return shipToAddress;
+    }
+
+    public InventoryList getCustomerInventoryList() {
+        return customerInventoryList;
+    }
+
+    public void setCustomerInventoryList(InventoryList customerInventoryList) {
+        this.customerInventoryList = customerInventoryList;
+    }
+
+    public float getTotalPrice() {
+        return totalPrice;
+    }
+
+    public void setTotalPrice(float totalPrice) {
+        this.totalPrice = totalPrice;
+    }
+
+    public JsonArray getAttributes() {
+        return attributes;
+    }
+
+    public void setAttributes(JsonArray attributes) {
+        this.attributes = attributes;
+    }
+
     public void setCreated(ZonedDateTime created) {
         this.created = created;
     }
@@ -45,5 +78,12 @@ public class Transaction {
         this.completed = completed;
     }
 
+    public void setShipToAddress(Address mailing) {
+        this.shipToAddress = mailing;
+    }
+
+    public void setCustomerId(String id) {
+        this.customerId = id;
+    }
 
 }
diff --git a/Model/src/main/java/edu/inventorym/model/TransactionManager.java b/Model/src/main/java/edu/inventorym/model/TransactionManager.java
index c852fe0..df2570a 100644
--- a/Model/src/main/java/edu/inventorym/model/TransactionManager.java
+++ b/Model/src/main/java/edu/inventorym/model/TransactionManager.java
@@ -17,19 +17,23 @@ public class TransactionManager {
     public TransactionList TRANSACTIONS = new TransactionList();
 
     public Transaction TransactRequest(Customer customer, InventoryList iPieces, Transaction transacted) {
+        transacted.setCustomerId(customer.getId());
+        transacted.setShipToAddress(customer.getMailing());
+        transacted.setCustomerInventoryList(iPieces);
+        compute(transacted);
         return transacted;
     }
 
-    public void compute(Transaction tran, TransactionOperationEnum operation) {
-
+    public void complete(Transaction tran) {
+        tran.setCompleted(ZonedDateTime.now());
     }
 
     public void compute(Transaction tran) {
-
-    }
-
-    public void complete(Transaction tran) {
-
+        float price = 0.0F;
+        for (InventoryPiece piece : tran.customerInventoryList) {
+            price += piece.computePrice();
+        }
+        tran.totalPrice = price;
     }
 
     public TransactionList findByCustomerEmail(String email) {
@@ -49,8 +53,7 @@ public class TransactionManager {
     }
 
     public void save() {
-        // TODO Auto-generated method stub
-        throw new UnsupportedOperationException("Unimplemented method 'save'");
+
     }
 
 }
diff --git a/Model/src/main/java/edu/inventorym/model/TransactionOperationEnum.java b/Model/src/main/java/edu/inventorym/model/TransactionOperationEnum.java
deleted file mode 100644
index dfd1238..0000000
--- a/Model/src/main/java/edu/inventorym/model/TransactionOperationEnum.java
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * license: GPLv3
- edu.inventorym
-*/
-package edu.inventorym.model;
-
-public enum TransactionOperationEnum {
-  Completed,
-  Draft,
-  Pricing,
-  Removed,
-  Shipping
-}
-
diff --git a/README.md b/README.md
index 2b7a113..f93d1fe 100644
--- a/README.md
+++ b/README.md
@@ -1,24 +1,16 @@
 # inventorym
 
-Inheritance: Shows inheritance relationships (Drawing, Painting, Print, Sculpture extending InventoryPiece)
-Associations: Shows composition relationships (Customer has Address, Transaction has Address and InventoryList)
 Enumerations: InventoryType and TransactionOperationEnum
-Exceptions: four application exception classes extend RuntimeException
-Manager Classes: Singleton pattern managers with their collections
-Collections: Custom list classes extending ArrayList
-
-
-Abstract base class (InventoryPiece) with 4 concrete implementations (Drawing, Painting, Print, Sculpture)
-Enumerations (InventoryType, TransactionOperationEnum)
-Manager classes (Singleton pattern): InventoryManager, CustomerManager, TransactionManager
-Model classes: Customer, Address, Transaction
-Collection classes: InventoryList, CustomerList, TransactionList
-Repository: DataRepository for persistence
-Exception classes: 4 custom runtime exceptions
+Exception Classes: Four custom exception types
+Value Object: Address class
+Customer Management: Customer, CustomerList, and CustomerManager
+Inventory Management: Abstract InventoryPiece with concrete implementations (Drawing, Painting, Print, Sculpture), plus InventoryList and InventoryManager
+Transaction Management: Transaction, TransactionList, and TransactionManager
+Data Repository: Singleton DataRepository for data operations
 
 Relationships shown:
 
-Inheritance (empty arrow heads)
-Composition (diamond arrow heads)
-Associations (open arrow heads)
-Dependencies (dashed lines)
\ No newline at end of file
+Inheritance (hollow arrows)
+Associations (regular arrows)
+Composition (diamond arrows)
+Dependencies (dashed arrows)
\ No newline at end of file
diff --git a/uml/classdiagram.dot b/uml/classdiagram.dot
index a79dc99..2bc7439 100644
--- a/uml/classdiagram.dot
+++ b/uml/classdiagram.dot
@@ -72,8 +72,8 @@ digraph InventoryManagementSystem {
     TransactionManager -> TransactionList [arrowhead=diamond, label="TRANSACTIONS"];
     
     // List contains relationships
-    InventoryList -> InventoryPiece [arrowhead=diamond, style=dashed, label="contains"];
-    CustomerList -> Customer [arrowhead=diamond, style=dashed, label="contains"];
+    InventoryList -> InventoryPiece [arrowhead=odiamond, style=dashed, label="contains 0..*"];
+    CustomerList -> Customer [arrowhead=odiamond, style=dashed, label="contains 0..*"];
     TransactionList -> Transaction [arrowhead=diamond, style=dashed, label="contains"];
     
     // Manager relationships
diff --git a/uml/classdiagram2.dot b/uml/classdiagram2.dot
new file mode 100644
index 0000000..22dc860
--- /dev/null
+++ b/uml/classdiagram2.dot
@@ -0,0 +1,84 @@
+digraph InventorySystem {
+    // Graph settings
+    rankdir=TB;
+    node [shape=record, fontname="Arial", fontsize=10];
+    edge [fontname="Arial", fontsize=9];
+    
+    // Abstract Class
+    InventoryPiece [label="{InventoryPiece\n«abstract»|+ id : String\l+ price : float\l+ created : ZonedDateTime\l+ title : String\l+ description : String\l+ Author : String\l- iventoryType : InventoryType\l|+ InventoryPiece(InventoryType)\l+ InventoryPiece()\l+ isArt(InventoryPiece) : Boolean\l+ getType() : String\l+ getId() : String\l+ setId(String) : void\l+ getPrice() : float\l+ setPrice(float) : void\l+ getCreated() : ZonedDateTime\l+ setCreated(ZonedDateTime) : void\l+ getTitle() : String\l+ setTitle(String) : void\l+ getDescription() : String\l+ setDescription(String) : void\l+ getAuthor() : String\l+ setAuthor(String) : void\l}", style=filled, fillcolor=lightyellow];
+    
+    // Concrete Classes extending InventoryPiece
+    Drawing [label="{Drawing|+ style : String\l+ technique : String\l+ category : String\l|+ Drawing()\l}"];
+    Painting [label="{Painting|- height : int\l- width : int\l- style : String\l- technique : String\l- category : String\l|+ Painting()\l}"];
+    Print [label="{Print|- openEditionType : String\l- category : String\l|+ Print()\l+ Print(String, String)\l+ getOpenEditionType() : String\l+ setOpenEditionType(String) : void\l+ getCategory() : String\l+ setCategory(String) : void\l}"];
+    Sculpture [label="{Sculpture|- material : String\l- weight : float\l|+ Sculpture()\l}"];
+    
+    // Enums
+    InventoryType [label="{«enumeration»\nInventoryType|PAINTING\lDRAWING\lPRINT\lSCULPTURE\l}", style=filled, fillcolor=lightblue];
+    TransactionOperationEnum [label="{«enumeration»\nTransactionOperationEnum|Completed\lDraft\lPricing\lRemoved\lShipping\l}", style=filled, fillcolor=lightblue];
+    
+    // Value Objects
+    Address [label="{Address|- street : String\l- city : String\l- state : String\l- zip : String\l|+ Address()\l+ Address(String, String, String, String)\l+ getStreet() : String\l+ setStreet(String) : void\l+ getCity() : String\l+ setCity(String) : void\l+ getState() : String\l+ setState(String) : void\l+ getZip() : String\l+ setZip(String) : void\l+ hashCode() : int\l+ equals(Object) : boolean\l+ toString() : String\l}"];
+    
+    // Domain Classes
+    Customer [label="{Customer|# id : String\l# updated : ZonedDateTime\l- phone : String\l- mailing : Address\l- email : String\l- nameFirst : String\l- nameLast : String\l|+ Customer(String, String, String, String)\l+ Customer()\l+ getEmail() : String\l+ getId() : String\l+ setId(String) : void\l+ getPhone() : String\l+ setPhone(String) : void\l+ getMailing() : Address\l+ setMailing(Address) : void\l+ setEmail(String) : void\l+ getNameFirst() : String\l+ setNameFirst(String) : void\l+ getNameLast() : String\l+ setNameLast(String) : void\l}"];
+    
+    Transaction [label="{Transaction|- id : String\l- created : ZonedDateTime\l- completed : ZonedDateTime\l- customerId : String\l- shipToAddress : Address\l- customerInventoryList : InventoryList\l- attributes : JsonArray\l|+ Transaction()\l+ getId() : String\l+ setId(String) : void\l+ getCreated() : ZonedDateTime\l+ setCreated(ZonedDateTime) : void\l+ getCompleted() : ZonedDateTime\l+ setCompleted(ZonedDateTime) : void\l}"];
+    
+    // Collection Classes
+    InventoryList [label="{InventoryList|+ InventoryList()\l}", style=filled, fillcolor=lightgreen];
+    CustomerList [label="{CustomerList|+ CustomerList()\l}", style=filled, fillcolor=lightgreen];
+    TransactionList [label="{TransactionList|+ TransactionList()\l+ add(Transaction) : boolean\l}", style=filled, fillcolor=lightgreen];
+    
+    // Manager Classes (Singletons)
+    InventoryManager [label="{«singleton»\nInventoryManager|- INSTANCE : InventoryManager\l+ INVENTORY : InventoryList\l|- InventoryManager()\l+ getInstance() : InventoryManager\l+ getArtPieceTypes() : Set\<InventoryType\>\l+ add(InventoryPiece) : void\l+ find(String) : InventoryPiece\l+ update(InventoryPiece) : InventoryPiece\l+ save() : void\l+ loadAll() : void\l+ Remove(InventoryPiece) : void\l}", style=filled, fillcolor=lightcoral];
+    
+    CustomerManager [label="{«singleton»\nCustomerManager|- INSTANCE : CustomerManager\l+ CUSTOMERS : CustomerList\l|+ getInstance() : CustomerManager\l+ add(Customer) : boolean\l- check(Customer) : void\l+ findById(String) : Customer\l+ findByEmail(String) : Customer\l}", style=filled, fillcolor=lightcoral];
+    
+    TransactionManager [label="{«singleton»\nTransactionManager|- INSTANCE : TransactionManager\l+ TRANSACTIONS : TransactionList\l|+ getInstance() : TransactionManager\l+ TransactRequest(Customer, InventoryList, Transaction) : Transaction\l+ compute(Transaction, TransactionOperationEnum) : void\l+ compute(Transaction) : void\l+ complete(Transaction) : void\l+ findByCustomerEmail(String) : TransactionList\l+ findByTransactionId(String) : TransactionList\l+ findByTransactionDate(ZonedDateTime) : TransactionList\l+ remove(Transaction) : void\l+ save() : void\l}", style=filled, fillcolor=lightcoral];
+    
+    // Utility Class
+    DataRepository [label="{«singleton»\nDataRepository|- INSTANCE : DataRepository\l|+ getInstance() : DataRepository\l+ generateRandomID(int) : String\l+ generateRandom10DigitID() : String\l+ WalkFileSystemTree(InventoryManager) : void\l+ WalkFileSystemTree(CustomerManager) : void\l+ WalkFileSystemTree(TransactionManager) : void\l+ mapJsonToObjectList(String, Class\<T\>) : List\<T\>\l}", style=filled, fillcolor=lavender];
+    
+    // Exception Classes
+    InvalidArtOperationException [label="{InvalidArtOperationException|+ InvalidArtOperationException(String)\l+ InvalidArtOperationException(String, Throwable)\l+ InvalidArtOperationException(Throwable)\l}", style=filled, fillcolor=pink];
+    
+    InvalidRecordDataException [label="{InvalidRecordDataException|+ InvalidRecordDataException(String)\l+ InvalidRecordDataException(String, Throwable)\l+ InvalidRecordDataException(Throwable)\l}", style=filled, fillcolor=pink];
+    
+    InvalidTransactionException [label="{InvalidTransactionException|+ InvalidTransactionException(String)\l+ InvalidTransactionException(String, Throwable)\l+ InvalidTransactionException(Throwable)\l}", style=filled, fillcolor=pink];
+    
+    InvalidTransOperationException [label="{InvalidTransOperationException|+ InvalidTransOperationException(String)\l+ InvalidTransOperationException(String, Throwable)\l+ InvalidTransOperationException(Throwable)\l}", style=filled, fillcolor=pink];
+    
+    // Inheritance relationships
+    InventoryPiece -> Drawing [dir=back, arrowtail=empty, label="extends"];
+    InventoryPiece -> Painting [dir=back, arrowtail=empty, label="extends"];
+    InventoryPiece -> Print [dir=back, arrowtail=empty, label="extends"];
+    InventoryPiece -> Sculpture [dir=back, arrowtail=empty, label="extends"];
+    
+    // Collection inheritance
+    InventoryList -> InventoryPiece [arrowhead=diamond, label="contains *"];
+    CustomerList -> Customer [arrowhead=diamond, label="contains *"];
+    TransactionList -> Transaction [arrowhead=diamond, label="contains *"];
+    
+    // Composition relationships
+    Customer -> Address [arrowhead=diamond, label="mailing"];
+    Transaction -> Address [arrowhead=diamond, label="shipToAddress"];
+    Transaction -> InventoryList [arrowhead=diamond, label="customerInventoryList"];
+    
+    // Manager aggregations
+    InventoryManager -> InventoryList [arrowhead=diamond, label="INVENTORY"];
+    CustomerManager -> CustomerList [arrowhead=diamond, label="CUSTOMERS"];
+    TransactionManager -> TransactionList [arrowhead=diamond, label="TRANSACTIONS"];
+    
+    // Dependencies
+    InventoryPiece -> InventoryType [style=dashed, arrowhead=open, label="uses"];
+    CustomerManager -> InvalidRecordDataException [style=dashed, arrowhead=open, label="throws"];
+    TransactionManager -> TransactionOperationEnum [style=dashed, arrowhead=open, label="uses"];
+    InventoryManager -> DataRepository [style=dashed, arrowhead=open, label="uses"];
+    CustomerManager -> DataRepository [style=dashed, arrowhead=open, label="uses"];
+    TransactionManager -> DataRepository [style=dashed, arrowhead=open, label="uses"];
+    InventoryPiece -> DataRepository [style=dashed, arrowhead=open, label="uses"];
+    TransactionManager -> Customer [style=dashed, arrowhead=open, label="uses"];
+    TransactionManager -> InventoryList [style=dashed, arrowhead=open, label="uses"];
+    DataRepository -> InventoryPiece [style=dashed, arrowhead=open, label="serializes"];
+}
\ No newline at end of file