March R McFadyen1 Activity Diagrams start end branch merge fork join guard transition swimlanes activity Used to present procedural steps (algorithm) that may involve concurrency. See pages

March R McFadyen2 Activity Diagrams - sequential Activity 1 Activity 2Activity 3 Activities 1, 2, 3 follow one another in sequence. Activity 3 cannot start until Activity 2 is done, etc.

March R McFadyen3 Activity Diagrams – conditional path Activity 1 Activity 2 [Balance > amount] [Balance <= amount] One of two paths is chosen Same symbol for decision as for merge

March R McFadyen4 Activity Diagrams - iteration Get next delta [ none left ] Check for existing dimension record Insert new dimension record [ does not exist ] Update existing dimension record [ exists ]

March R McFadyen5 Activity Diagrams – parallelism/concurrency Activity 1 Activity 2 Activity 3 Both paths are performed in parallel. Activity 1 and 2 begin when Activity 0 is finished. Activity 0 Activity 4 Activity 4 begins when Activity 1 and 3 have both completed

March R McFadyen6 Updating a Star Schema Churn Star Schema from The Official Guide to Informix/Red Brick Data Warehousing Rate_plan Period Customer Churn_reason Carrier Telephone Churn credit_limit outstanding_balance current_bill A Star Schema is a specialized ERD used in Data Warehousing. To update the database, we: (1) update each Dimension, and then (2) update the Fact table

March R McFadyen7 Updating a Star Schema Update Customer Update Churn Update Rate plan Update Churn Reason Update Telephone Update Carrier Update Period

March R McFadyen8 Updating a Star Schema Update Customer Update Churn Update Rate plan Update Churn Reason Update Telephone Update Carrier Update Period The dimensions can be updated independently of one another. Those activities can be carried on concurrently

March R McFadyen9 Activity Diagrams Activity 1 Activity 2 Activity 3 Swimlanes When we assign activities to particular organizational units, then we can partition the flow into swimlanes, one swimlane per unit. Activity 0 Activity 4 Org 1Org 2Org 3Org 4

March R McFadyen10 Activity Diagrams Workflow for an Order Request product Customer SalesWarehouse A customer requests a product. The order is handled by Sales, and then the Warehouse picks the materials and ships the order. Then, the customer will receive the order and Sales will send out the bill. When the customer receives the bill, it is paid, and the order is closed by Sales. Process Order Pick & Ship Receive Order Send Bill Pay Bill Order Closed