Case Study 10
10
Inventory Management at Blue Bell
Inventory Management at Blue Bell
Problem Description
Blue Bell is a large apparel manufacturer. They run three major businesses. The largest is
the Wrangler group. The Wrangler group manufactures jeans and several other lines of
sports and casual apparel. Wrangler markets to men, women, and children in the USA
and has a substantial international business. Red Kap, the second largest business,
makes a variety of durable garments used for on-the-job wear by production, service, and
white-collar personnel. Jantzen, the third major business, manufactures a variety of sports
and casual apparel product lines, including popular lines of swimwear and sweaters.
Each of the above production lines breaks down into styles, lots, sizes, and stock keeping
units (SKU). The management has realized that the number of product lines, styles, and
SKUs had grown tremendously. The production process had incorporated several new
automated manufacturing operations in response to changes in customer taste. The
management was concerned about the high investment in working capital. A large part of
the working capital is inventories. In this process of extending the business, it is crucial for
Blue Bell to have an effective coordination of their activities. Since the investment on the
inventories is quite high, we will propose a database management system that will help
Blue Bell manage their inventories.
Database Design
We present here the main entity types of this database. For each entity type, we provide
some of the corresponding attributes. Use this information in order to: (a) Build an
Enhanced E-R diagram; (b) Transform the Enhanced E-R diagram to a relational
database. Identify the primary key(s) and the foreign key(s) for each relation. Draw the
relational integrality constraints; (c) For each of the relations created, indicate its normal
form. If the relation is not in the 3NF, decompose it into 3NF relations.
1.
Production line: The main attributes are identification number, name (e.g., jeans, tshirts, swimwear production line, etc.), and classification (e.g., menswear, women’s
wear, boys’ wear and kids).
2.
Style: The main attributes are identification number, name, etc. Note that there are
different styles for a production line. For example, the jeans production line produces
the following styles: straight-leg jeans, boot-leg cut jeans, etc.
3.
Lot: The main attributes are identification number, name (e.g., blue, green, etc.), etc.
Note that there are different lots produced for a particular style. For example, the
straight-leg jeans come in blue, green, black, etc.
4.
Size: The main attributes are identification number, description, etc. Note that
depending on the product, the measurements reported vary. For example, for pants
we keep information on waist number and length number.
5.
Customer: The main attributes are identification number, name, address, telephone
number, etc.
6.
Transaction: The main attributes are identification number, date, quantity, total dollar
amount paid/received, etc.
Case Study 10
7.
Inventory Management at Blue Bell
Product: The main attributes are identification number, name, on-hand inventory,
outstanding orders, historical information on production (includes date and quantity
produced), etc. Note that a final product is produced in a particular production line
and has a particular style, lot, and size.
Access Application Development
The following are some of the queries, forms, and reports one can create in order to
increase the functionality of the database:
Queries:
1.
2.
3.
The managers want to identify customers with whom the company is interested in
keeping long-time relationships. The following queries help the managers in making
their selections:
a.
Find the top ten customers with whom the company does most of its business.
Include in this query the identification number and name of the customers as well
as the value of the products sold to them so far.
b.
List the top ten customers who have been doing business with the company for
more than five years.
c.
List the top five customers that have the highest yearly revenues.
The management is considering a reallocation of resources. They plan to allocate
more resources to products that sell most, have a high profit margin, etc. The
following queries will help the management to make a better decision:
a.
List the five final products that sold most during the last year. Include in this
query the name and identification number of the product, as well as the quantity
sold in the last year and the dollar amount generated.
b.
List the five styles that sold the most last year. Include in the query the quantity
sold per style and the dollar amount generated.
c.
Find the size that sold the least last year. Include in this query the quantity sold
per size and the dollar amount generated.
d.
List the ten final products that have the highest level of inventory. Include the
following in this query: identification number, name, amount in the inventory, and
the value of the inventory.
e.
List the five final products that have the highest profit margin. For each product,
present the quantity sold during the last year and the profit made.
The following information helps the management to update the production schedule in
such a way that inventory level is minimal and demand is fully satisfied:
a.
Find the period of time (the month) that has the highest sales. Include in this
query the total quantity sold and the dollar amount generated.
b.
Identify the period of time that has the least sales.
c.
Find the product that sells the most. Include in this query the identification
number of the product, amount sold, and the corresponding value.
d.
Identify the quantity on-hand per product in each month during the last year.
e.
Identify the quantity sold per product in each month during the last year.
Case Study 10
Inventory Management at Blue Bell
Forms:
1.
Create a user sign-in form together with a registration form for new users.
2.
Create the following data entry forms that are used for database administrative
functions: products, customers, production lines, transactions, etc. These forms allow
the user to add, update, and delete information about products, customers,
production lines, transactions, etc.
3.
Create a form that allows the user to browse through the names of the final products.
Create a subform that presents the following information about each product: the
corresponding production line, style, lot, and size; the level of on-hand inventory; the
number of backorders; the unit cost, and the unit price.
4.
Create a form that allows the user to choose a customer from a combo box. Create a
subform that presents for the selected customer information about orders that have
not yet been delivered.
5.
Create a form that allows the user to choose from a list box a production line. Create
a subform that presents for the selected production line the identification number and
name of the final products produced, monthly production, unit cost, and unit price.
6.
We presented a number of queries that can be created to help the managers decide
about resource allocation. Create a form that enables the user to run these queries.
Command buttons can be used for this purpose. When the user clicks on a particular
command button, one of the queries is run, and the outcome is presented.
Design a logo for this database. Put this logo in the forms created above as well as on the
reports that you will be creating next. Include the following in the forms created: record
navigation command buttons, record operations command buttons, and form operations
command buttons as needed.
Reports
1.
Prepare a report for each sales transaction. This report should include a date, name
and identification number of the customer, name and identification number of the
product sold, the quantity sold, and the value of sale.
2.
Prepare a report that presents the inventory level in the company at the end of the
month. This report should include for each product the identification number and
name. Give details on production line, style, lot, size, amount in the inventory, and
value of the corresponding final product.
3.
At the end of the year, the managers prepare a balance of payments. Among other
items, include in this report the total amount of money received during the last year by
each customer, and include the total amount of money in the inventory.
4.
Use the label wizard to create labels with the address of each customer.
5.
Use the chart wizard to plot the following information:
a.
Total sales (in dollar amount) per year during the last ten years.
b.
The value of the inventory per year during the last ten years.
c.
For each product, the unit cost and the unit price per year during the last ten
years.
Case Study 10
d.
Inventory Management at Blue Bell
For the product that sold most in the last year, plot the yearly sales per year
during the last ten years.
Visual Basic.NET Application Development
This database application can be used by customers, managers, the database
administrator, etc. In the following figure we present a tentative layout of the system.
Welcome Screen
Customer
Information
Final
Products
Orders
Inventory
Updates
Login
Req.
Present Results
Exit the Database
In the welcome screen, the user can choose one of the five options presented. We give
details about the forms or set of forms to be included in each option; however, you are
encouraged to add other forms you find important.
Customer Information: The user can search the database to retrieve information about a
customer. We suggest that related search queries and forms already created in the
Access Application Development section be included in here. These forms will enable the
user to: find the name, address, and telephone number of a customer; identify the most
valuable customers; find whether a customer has set an order; etc.
Final Products: The user can browse the database to learn more about a final product.
The user can identify the following: the production line where the product is produced; the
level of inventory, unit cost, unit price, and total sales for the current year; etc. We
encourage in here the use of statistical analysis tools and usage of plots similar to the
ones created in the Access Application Development section.
Orders: This option provides information about orders, such as outstanding orders, due
date, quantity ordered, value of the order, etc.
Inventory: This option provides information about the current inventory.
Update: The update form requires an administrator login name and password. This form
allows the user to add/delete/update the information kept in this database about products,
customers, orders, etc.
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Case Study 10
Inventory Management at Blue Bell
Subject to :
Web Extension
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are managers,
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(3)
the status of an order, etc. The managers use the database in order to learn
about the sales
check
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, the
(4)inventory level of a product, etc. Only
the database administrator has access to the data entry forms.
z kt  {0,1}
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(5)
Develop an ASP.NET web application that will enable the users to access the database
and perform the activities described above. Your application will have forms similar to the
ones described in the VB.NET Application section.
Reference
J. R. Edwards, H. M. Wagner, and W. P. Wood, “Blue Bell trims its inventory,” Interfaces
15(1): 34-52, 1985