Purchase order processing UML activity diagram

This purchase order processing UML activity diagram was created on the base of activity diagram from the software architecture documentation wiki of the Software Engineering Institute (SEI) of Carnegie Mellon University (CMU).
[wiki.sei.cmu.edu/ sad/ index.php/ Image:PurchaseOrderActivityDiagram.png]
"A purchase order (PO) is a commercial document and first official offer issued by a buyer to a seller, indicating types, quantities, and agreed prices for products or services. Acceptance of a purchase order by a seller forms a contract between the buyer and seller, so no contract exists until the purchase order is accepted. It is used to control the purchasing of products and services from external suppliers.
Creating a purchase order is typically the first step of the purchase to pay process in an ERP system." [Purchase order. Wikipedia]
This purchase order processing UML activity diagram example was created using the ConceptDraw PRO diagramming and vector drawing software extended with the ATM UML Diagrams solution from the Software Development area of ConceptDraw Solution Park.

"A registered user is one who uses a program or a website and provides his/ her credentials, effectively proving his/ her identity. ...
Generally speaking, any person can become a registered user by providing some credentials, usually in the form of a username (or email) and password. After that, one can access information and privileges unavailable to non-registered users, usually referred to simply as guests. The action of providing the proper credentials for a website is called logging in, or signing in." [Registered user. Wikipedia]
The UML activity diagram example "User registration" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

"An automated teller machine or automatic teller machine" (ATM) (American, Australian, Singaporean, Indian, and Hiberno-English), also known as an automated banking machine (ABM) (Canadian English), cash machine, cashpoint, cashline or hole in the wall (British, South African, and Sri Lankan English), is an electronic telecommunications device that enables the clients of a financial institution to perform financial transactions without the need for a cashier, human clerk or bank teller.
On most modern ATMs, the customer is identified by inserting a plastic ATM card with a magnetic stripe or a plastic smart card with a chip that contains a unique card number and some security information such as an expiration date or CVVC (CVV). Authentication is provided by the customer entering a personal identification number (PIN). The newest ATM at Royal Bank of Scotland allows customers to withdraw cash up to £100 without a card by inputting a six-digit code requested through their smartphones.
Using an ATM, customers can access their bank accounts in order to make cash withdrawals, get debit card cash advances, and check their account balances as well as purchase pre-paid mobile phone credit. If the currency being withdrawn from the ATM is different from that which the bank account is denominated in (e.g.: Withdrawing Japanese yen from a bank account containing US dollars), the money will be converted at an official wholesale exchange rate. Thus, ATMs often provide one of the best possible official exchange rates for foreign travellers, and are also widely used for this purpose." [Automated teller machine. Wikipedia]
The UML activity diagram example "Cash withdrawal from ATM" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.