Use-Case Definitions
Recall that in Chapter 4 we defined many use-cases and then assigned them to one of three Remulak project increments. Providing for a more informed estimate while still at an early stage of the project requires an in-depth flyby of all the project's use-cases. At a minimum, before estimating a project, we must do the following:
1. | Identify events. |
2. | Identify use-cases. |
3. | Assign events to use-cases. |
4. | Identify happy paths for all use-cases. |
5. | Identify alternate pathways for all use-cases. |
6. | Produce detailed task steps for all use-case happy paths. |
7. | Assign use-cases to project increments (both use-cases and pathways may need to be assigned because they may be split across increments). |
8. | Describe in detail all use-case pathways for the project's first increment. |
Steps 1 through 5 were completed in the book, primarily in Chapter 4. The subsections that follow contain the completed use-case templates for all of Increment 1. A look at the happy paths for each use-case follows the templates.
The Process Orders Use-Case
Description:
This use-case starts when an order is either initiated or inquired about. It handles all aspects of the initial definition and authorization of an order, and it ends when the order clerk completes a session with a customer.
Location(s): Newport Hills, Washington.
Assumption(s):
Orders will be taken by the order clerk until the customer is comfortable with the specialized services being provided.
Precondition(s):
Order clerk has logged into the system.
Postcondition(s):
Order is placed.
Inventory is reduced.
Primary (Happy) Path:
Customer calls and orders a guitar and supplies, and pays with a credit card.
Alternate Pathway(s):
Customer calls and orders a guitar and supplies, and uses a purchase order.
Customer calls and orders a guitar and supplies, and uses the Remulak easy finance plan to pay.
Customer calls and orders an organ, and pays with a credit card.
Customer calls and orders an organ, and uses a purchase order.
Exception Pathway(s):
Customer calls to place an order using a credit card, and the card is invalid.
Customer calls with a purchase order but has not been approved to use the purchase order method.
Customer calls to place an order, and the desired items are not in stock.
The Maintain Orders Use-Case
Description:
This use-case starts when an order is modified in any way. It handles all aspects of the order modification, and it ends when the order clerk completes the order modification session.
Location(s): Newport Hills, Washington.
Assumption(s):
Orders will be modified by the order clerk.
Precondition(s):
Order clerk has logged into the system.
Postcondition(s):
Order is modified.
Inventory is reduced or increased.
Primary (Happy) Path:
Customer calls to inquire about an order's status.
Alternate Pathway(s):
Customer calls to change a product quantity for one order item on an order.
Customer calls to cancel an order.
Customer calls to add a new item to an order.
Customer calls to delete an item from an order.
Customer calls to change the shipping terms of an order.
Customer buys an extended warranty on an item.
Customer calls to change the billing method on an order.
Exception Pathway(s):
Customer calls to cancel an order that can't be found in the system.
Customer calls to add a warranty to an item that is no longer valid for the time that the product has been owned.
Customer calls to add to an order, and the product to be added can't be found in the system.
The Maintain Inventory Use-Case
Description:
This use-case starts when a product is ordered and/or added to stock. It handles all aspects of inventory management, and it ends when either new stock is ordered or new stock has been accounted for in inventory.
Location(s): Newport Hills, Washington.
Assumption(s):
Only products carried by Remulak are ordered or processed into inventory (i.e., unauthorized products are not sold).
Precondition(s):
Replenished products have product numbers assigned.
Postcondition(s):
Product is ordered.
Product is checked into inventory.
Primary (Happy) Path:
Product arrives at the warehouse with a copy of the purchase order attached.
Alternate Pathway(s):
Product arrives at the warehouse with a purchase order that is attached but incomplete as to the products ordered.
Product is ordered to replenish stock on hand.
Product is ordered to fill a special order.
Product is ordered to fill a back order.
Products are accounted for through a physical inventory count.
Exception Pathway(s):
Product arrives with no attached purchase order or bill of lading.
The Shipping Use-Case
Description:
This use-case starts when an order is either completely ready or partially ready for shipment. It handles all aspects of shipping, and it ends when the order is shipped and is either partially filled or completely filled.
Actor(s): Packaging clerk, shipping clerk.
Location(s): Newport Hills, Washington.
Assumption(s):
For an order to be partially fulfilled, the customer must have authorized partial shipments.
Precondition(s):
Packaging clerk and shipping clerk have valid access to the system and are logged on.
Postcondition(s):
Order is shipped.
Primary (Happy) Path:
Entire order is shipped from stock on hand to a customer.
Alternate Pathway(s):
Partial order is shipped from stock on hand to a customer.
Entire order is shipped to a customer sourced directly from a third-party supplier.
Exception Pathway(s):
Order is ready to ship, and there is no shipping address.
The Invoicing Use-Case
Description:
This use-case starts when an order is invoiced to a customer. It handles all aspects of invoicing, and it ends when the order is invoiced and payment is received.
Actor(s): Accounting system, billing clerk.
Location(s): Newport Hills, Washington.
Assumption(s):
For an invoice to be produced, there must be a valid order.
An order can have more than one invoice (to accommodate authorized partial shipments).
Invoicing is interfaced to accounting nightly.
Precondition(s):
Billing clerk has valid access to the system and is logged on.
Postcondition(s):
Order is invoiced, and/or funds are collected.
The accounting system is updated as to the invoiced orders.
Primary (Happy) Path:
Order is invoiced and sent to the customer, indicating that payment was satisfied via credit card billing.
Alternate Pathway(s):
Overdue notice is sent to a customer for a past-due account.
Subledger transactions are interfaced to the accounting system.
Exception Pathway(s):
None
The Maintain Relationships Use-Case
Description:
This use-case starts when a relationship with a customer or supplier requires attention. It handles all aspects of Remulak's relationships with customers and suppliers, and it ends when a relationship is either created or maintained for a customer or supplier.
Actor(s): Customer service clerk.
Location(s): Newport Hills, Washington.
Assumption(s):
For a customer to order a product or a supplier to ship products, their relationships must be established.
Precondition(s):
Customer clerk has valid access to the system and is logged on.
Postcondition(s):
Relationship is either created or maintained.
Primary (Happy) Path:
Customer calls to change his/her mailing address.
Alternate Pathway(s):
Customer calls to change his/her default payment terms and payment method.
New customer is added to the system.
Prospective customer is added to the system.
New supplier is added to the system.
Supplier calls to change its billing address.
Exception Pathway(s):
None.
The Decision Support Use-Case
Description:
This use-case starts when a predefined or undefined request for information is made. It handles all aspects of decision support effort, and it ends when a reply is formulated for the inquiry.
Location(s): Newport Hills, Washington.
Assumption(s):
None.
Precondition(s):
Manager has valid access to the system and is logged on.
Postcondition(s):
Reply is formulated for request.
Primary (Happy) Path:
Manager requests a back-order status report.
Alternate Pathway(s):
It is time to print the back-order report.
Exception Pathway(s):
None.