Design A Warehouse Management System - Object-Oriented Design

Requirements

Functional:

Expose methods to check free space and receive stock from partners.
Expose methods to check stock and place orders for customers.
Arrange storage locations in the order they are placed to facilitate easier dispatch
Notify the logistic partner for transport
Track partner and customer orders along the supply chain.

Non-functional:

It could be used for any warehouse with any capacity
The ordering of storage locations mechanism should be easily changed.

Define Core Objects

Warehouse, Order, PartnerOrder, CustomerOrder, Item

StorageManager, ArrangementStrategy, StagingQueueArrangementStrategy

Analyze Relationships

Warehouse has a StorageManager

StorageManager has a ArrangementStrategy

Order has a Warehouse

Order has Items

StagingQueueArrangementStrategy is an ArrangementStrategy

PartnerOrder is an Order

CustomerOrder is an Order

StagingQueueArrangementStrategy has a queue.

Queue stagingQueue = new LinkedList<>();

This represents the staging queue, which holds items ready to be dispatched after placing the order.

Establish Hierarchy

FrequencyArrangementStrategy is an ArrangementStrategy

PartnerOrder is an Order

CustomerOrder is an Order

Design Patterns

Strategy pattern to sort StorageLocations

Define Class Members (write code)

package com.example.warehouse.entity.item;
public abstract class Item {
private String id;
private int count;

public String getId() {
    return id;
}

/**
 * @return the count
 */
public int getCount() {
    return count;
}

/**
 * @param count the count to set
 */
public void setCount(int count) {
    this.count = count;
}

public abstract void incrementCount(int count);

public abstract void decrementCount(int count);

}
package com.example.warehouse.entity.item;
public class ConsumerItem extends Item {
private int count;
@Override
public void incrementCount(int count) {
    this.count += count;
}

@Override
public void decrementCount(int count) {
    this.count += count;
}

}
package com.example.warehouse.entity.order;
import com.example.warehouse.entity.item.Item;
import com.example.warehouse.entity.warehouse.Warehouse;
public abstract class Order {
private Item item;
private int count;
private Warehouse warehouse;
private String status;
/**
 * @return the item
 */
public Item getItem() {
    return item;
}

/**
 * @param item the item to set
 */
public void setItem(Item item) {
    this.item = item;
}

/**
 * @return the count
 */
public int getCount() {
    return count;
}

/**
 * @param count the count to set
 */
public void setCount(int count) {
    this.count = count;
}

/**
 * @return the warehouse
 */
public Warehouse getWarehouse() {
    return warehouse;
}

/**
 * @param warehouse the warehouse to set
 */
public void setWarehouse(Warehouse warehouse) {
    this.warehouse = warehouse;
}

/**
 * @return the status
 */
public String getStatus() {
    return status;
}

/**
 * @param status the status to set
 */
public void setStatus(String status) {
    this.status = status;
}

public abstract boolean isValid();

public abstract void place();

}
package com.example.warehouse.entity.order;
public class CustomerOrder extends Order {
@Override
public boolean isValid() {
    return getItem().getCount() &gt;= getCount();
}

@Override
public void place() {
    if (isValid()) {
        getItem().incrementCount(getCount());
        getWarehouse().getStorageManager().prepareForDispatch(getItem(), getCount());
    }
}

}
package com.example.warehouse.entity.order;
public class PartnerOrder extends Order {
@Override
public boolean isValid() {
    return getWarehouse().getCapacity() &gt;= getCount();
}

@Override
public void place() {
    if (isValid()) {
        getItem().incrementCount(getCount());
    }
}

}
package com.example.warehouse.entity.warehouse;
import com.example.warehouse.service.storagemanager.StorageManager;
public abstract class Warehouse {
private StorageManager storageManager;
private int capacity;
/**
 * @return the storageManager
 */
public StorageManager getStorageManager() {
    return storageManager;
}

/**
 * @param storageManager the storageManager to set
 */
public void setStorageManager(StorageManager storageManager) {
    this.storageManager = storageManager;
}

/**
 * @return the capacity
 */
public int getCapacity() {
    return capacity;
}

/**
 * @param capacity the capacity to set
 */
public void setCapacity(int capacity) {
    this.capacity = capacity;
}

}
package com.example.warehouse.entity.warehouse;
public class WarehouseImpl extends Warehouse {
}
package com.example.warehouse.service.storagemanager;
import com.example.warehouse.entity.item.Item;
public class StorageManager {
ArrangementStrategy arrangementStrategy;
StorageManager(ArrangementStrategy arrangementStrategy) {
    this.arrangementStrategy = arrangementStrategy;
}

public void prepareForDispatch(Item item, int count) {
    arrangementStrategy.arrangeStorageForDispatch(item, count);
}

}
package com.example.warehouse.service.storagemanager;
import com.example.warehouse.entity.item.Item;
public abstract class ArrangementStrategy {
abstract void arrangeStorageForDispatch(Item item, int count);

}
package com.example.warehouse.service.storagemanager;
import java.util.LinkedList;
import java.util.Queue;
import com.example.warehouse.entity.item.Item;
public class StagingQueueArrangementStrategy extends ArrangementStrategy {
Queue&lt;Object[]&gt; stagingQueue = new LinkedList&lt;&gt;();

@Override
void arrangeStorageForDispatch(Item item, int count) {
    stagingQueue.offer(new Object[] { item.getId(), count });
}

}

Adhere to SOLID Guidelines

Consider Scalability and Flexibility

It could be used for any warehouse with any capacity
The ordering of storage locations mechanism could be easily changed

Create/Explain your diagram(s)

Try creating a class, flow, state and/or sequence diagram using the diagramming tool. Mermaid flow diagrams can be used to represent system use cases. You can ask the interviewer bot to create a starter diagram if unfamiliar with the tool. Briefly explain your diagrams if necessary...

Future improvements

Critically examine your design for any flaws or areas for future improvement...

Requirements

Functional:

Expose methods to check free space and receive stock from partners.
Expose methods to check stock and place orders for customers.
Arrange storage locations in the order they are placed to facilitate easier dispatch
Notify the logistic partner for transport
Track partner and customer orders along the supply chain.

Non-functional:

It could be used for any warehouse with any capacity
The ordering of storage locations mechanism should be easily changed.

Define Core Objects

Warehouse, Order, PartnerOrder, CustomerOrder, Item

StorageManager, ArrangementStrategy, StagingQueueArrangementStrategy

Analyze Relationships

Warehouse has a StorageManager

StorageManager has a ArrangementStrategy

Order has a Warehouse

Order has Items

StagingQueueArrangementStrategy is an ArrangementStrategy

PartnerOrder is an Order

CustomerOrder is an Order

StagingQueueArrangementStrategy has a queue.

Queue stagingQueue = new LinkedList<>();

This represents the staging queue, which holds items ready to be dispatched after placing the order.

Establish Hierarchy

FrequencyArrangementStrategy is an ArrangementStrategy

PartnerOrder is an Order

CustomerOrder is an Order

Design Patterns

Strategy pattern to sort StorageLocations

Define Class Members (write code)

package com.example.warehouse.entity.item;
public abstract class Item {
private String id;
private int count;

public String getId() {
    return id;
}

/**
 * @return the count
 */
public int getCount() {
    return count;
}

/**
 * @param count the count to set
 */
public void setCount(int count) {
    this.count = count;
}

public abstract void incrementCount(int count);

public abstract void decrementCount(int count);

}
package com.example.warehouse.entity.item;
public class ConsumerItem extends Item {
private int count;
@Override
public void incrementCount(int count) {
    this.count += count;
}

@Override
public void decrementCount(int count) {
    this.count += count;
}

}
package com.example.warehouse.entity.order;
import com.example.warehouse.entity.item.Item;
import com.example.warehouse.entity.warehouse.Warehouse;
public abstract class Order {
private Item item;
private int count;
private Warehouse warehouse;
private String status;
/**
 * @return the item
 */
public Item getItem() {
    return item;
}

/**
 * @param item the item to set
 */
public void setItem(Item item) {
    this.item = item;
}

/**
 * @return the count
 */
public int getCount() {
    return count;
}

/**
 * @param count the count to set
 */
public void setCount(int count) {
    this.count = count;
}

/**
 * @return the warehouse
 */
public Warehouse getWarehouse() {
    return warehouse;
}

/**
 * @param warehouse the warehouse to set
 */
public void setWarehouse(Warehouse warehouse) {
    this.warehouse = warehouse;
}

/**
 * @return the status
 */
public String getStatus() {
    return status;
}

/**
 * @param status the status to set
 */
public void setStatus(String status) {
    this.status = status;
}

public abstract boolean isValid();

public abstract void place();

}
package com.example.warehouse.entity.order;
public class CustomerOrder extends Order {
@Override
public boolean isValid() {
    return getItem().getCount() &gt;= getCount();
}

@Override
public void place() {
    if (isValid()) {
        getItem().incrementCount(getCount());
        getWarehouse().getStorageManager().prepareForDispatch(getItem(), getCount());
    }
}

}
package com.example.warehouse.entity.order;
public class PartnerOrder extends Order {
@Override
public boolean isValid() {
    return getWarehouse().getCapacity() &gt;= getCount();
}

@Override
public void place() {
    if (isValid()) {
        getItem().incrementCount(getCount());
    }
}

}
package com.example.warehouse.entity.warehouse;
import com.example.warehouse.service.storagemanager.StorageManager;
public abstract class Warehouse {
private StorageManager storageManager;
private int capacity;
/**
 * @return the storageManager
 */
public StorageManager getStorageManager() {
    return storageManager;
}

/**
 * @param storageManager the storageManager to set
 */
public void setStorageManager(StorageManager storageManager) {
    this.storageManager = storageManager;
}

/**
 * @return the capacity
 */
public int getCapacity() {
    return capacity;
}

/**
 * @param capacity the capacity to set
 */
public void setCapacity(int capacity) {
    this.capacity = capacity;
}

}
package com.example.warehouse.entity.warehouse;
public class WarehouseImpl extends Warehouse {
}
package com.example.warehouse.service.storagemanager;
import com.example.warehouse.entity.item.Item;
public class StorageManager {
ArrangementStrategy arrangementStrategy;
StorageManager(ArrangementStrategy arrangementStrategy) {
    this.arrangementStrategy = arrangementStrategy;
}

public void prepareForDispatch(Item item, int count) {
    arrangementStrategy.arrangeStorageForDispatch(item, count);
}

}
package com.example.warehouse.service.storagemanager;
import com.example.warehouse.entity.item.Item;
public abstract class ArrangementStrategy {
abstract void arrangeStorageForDispatch(Item item, int count);

}
package com.example.warehouse.service.storagemanager;
import java.util.LinkedList;
import java.util.Queue;
import com.example.warehouse.entity.item.Item;
public class StagingQueueArrangementStrategy extends ArrangementStrategy {
Queue&lt;Object[]&gt; stagingQueue = new LinkedList&lt;&gt;();

@Override
void arrangeStorageForDispatch(Item item, int count) {
    stagingQueue.offer(new Object[] { item.getId(), count });
}

}

Adhere to SOLID Guidelines

Consider Scalability and Flexibility

It could be used for any warehouse with any capacity
The ordering of storage locations mechanism could be easily changed

Create/Explain your diagram(s)

Future improvements

Critically examine your design for any flaws or areas for future improvement...