Decomposition Subactivity Modified Diagram Signals A signal indicates

Decomposition / Sub-activity

Modified Diagram

Signals • A signal indicates that the activity • receives an event from an outside process. • A time signal occurs because of the passage of time. • end of a month in a financial period • microsecond in a real-time controller

Accepting/Sending Signals

Flow / edges

Pins and Transformation • Actions can also have parameters • We can show parameters by using pins. • output parameters of an outbound action match the input parameters of another • Otherwise, we can indicate using transformation: an expression that's free of side effects

Expansion Regions • An activity diagram area • actions occur once for each item in a collection. • action's output triggers multiple invocations of another action

Flow Final • indicates the end of one particular flow • NOT the end of activity diagram

Joint Specification • A Boolean expression attached to a join • if true, an output token is emitted • By default, a joint does not restrict any flow

Partitions • Activity diagrams do not tell you who does what • We don’t know • which class is responsible for each action • which part of an organization carries out which action • To show, we can use partitions • Also known as swim lanes • We can also use 2 D-grid

Case Study: Online Shopping Store • Online customer can browse or search items, view specific item, add it to shopping cart, view and update shopping cart, checkout. User can view shopping cart at any time. Checkout is assumed to include user registration and login. • Shopping cart can be checked out at any time • User can checkout any time. • For this case study, following are atomic actions: • Search Items, Browse Items, View Items, Add to Shopping Cart, Update Shopping Cart, View Shopping Cart, Checkout – or more.

Diagram is taken from http: //www. uml-diagrams. org/