The System
Identifying the Purpose of the System
- develop an overall purpose statement of 25 words or less. Why this system?
- Keep the overall goal, critical success factor, always in front of you.
- "To support, to help, to facilitate".
Connie's Wish List
- scan items and automatically price them
- know whether an item is on sale
- automatically total the sale and calculate tax
- handle purchases and returns
- handle payments with cash, check, or charge
- authorize checks and cards
- calculate change when working with cash or checks
- record all of the information about a customer transaction
- balance the cash in the drawer with the amount recorded by the point-of-sale system.
Why?
- speed up checkout time
- reduce the number of pricing errors
- reduce the labor required to ticket the item with a price, originally and when
- prices change.
Summary
to help each cashier work more effectively during checkout, to keep good records of each sale, and to store more efficient store operations.
Identify System Features
Logging Important Information
- to maintain prices based upon UPC
- to maintain tax categories (categories, rates, and effective dates)
- to maintain the authorized cashiers
- to maintain what items we sell in a store
- to log the results of each sale in a store
Conducting Business
- to price each item, based upon its UPC
- to subtotal, calculate tax, and total
- to accept payment by cash, check, or charge
Analyzing Business Results
- to count how many of each item sold
- to count how much we received in cash, check, or credit card sales
- to assess how each cashier is performing
- to assess how each store is performing
Working with Interacting Systems
to obtain authorization from one or more credit (or check) authorization system.
Selecting Objects
Select Actors
- Person
Select Participants
- cashier
- head cashier
- customer
If there is no difference between cashier
and head cashier
then they should be put into 1 common class.
Select Places
- Store
- Shelf
The system doesn't keep track of the shelf
.
Select Transactions
- sale
- every sale is a collection of sale line items
- return
- payment
- session
Select Container Classes
- cashiers
- registers
- items
Select Tangible Things
- item
- register
- cash drawer
- Tax Category (Descriptive things)