activity diagram

Our chain of pharmacies is considering implementing a self-service checkout system, called SelfCheck in order to reduce the staff required to man the cash registers.  With the resources freed up by the automated checkouts, our goal is to add more pharmacy technicians to improve satisfaction with the prescription-filling process. 

One use case of the SelfCheck system is named Scan Membership Card.  Our pharmacies have a customer loyalty program that uses the little keychain cards like many grocery stores.  SelfCheck is built to handle this and a customer may scan their membership card to tell the system to invoke membership benefits and discounts.  They will receive the same membership benefits as checking out as they would at a regular register.

On the following page, draw an activity diagram with swimlanes (partitions) to model the Scan Membership Card use case steps described below:

Scan Membership Card Activities:

The customer scans their membership card over the Selfcheck barcode reader.  Selfcheck validates that the barcode was swiped correctly.  If unsuccessful, Selfcheck displays an error message and then the use case is done.   If successful, Selfcheck will search for the customers identification number.  If not found, SelfCheck displays an error message and then the use case is done. 

If the customer identification number is found, the next two activities can be performed simultaneously.  SelfCheck will apply discounts to already scanned items, while at the same time setting a discount flag to make sure that goods scanned in the future also receive a discount, if applicable.  Once these two activities are done, Selfcheck will display a discounts applied message and then the use case is done.