Information Systems Concepts Activity Diagrams Roman Kontchakov Birkbeck, University of London Based on Chapter 5 of Bennett, McRobb and Farmer: Object Oriented Systems Analysis and Design Using UML, (4th Edition), McGraw Hill, 2010 1 Outline Activity Diagrams Section 5.3 (pp. 122 – 128) 2 Purpose of Activity Diagrams Activity Diagrams can be used to model high-level business tasks in the early stages of a project or when the relevant objects or classes have not been identified system functions (represented by use cases) or object operations but communication/sequence diagrams are closer to the spirit of object-orientation 3 Notation of Activity Diagrams Activity Diagrams are essentially Flowcharts / Petri nets in an object-oriented context sequence, selection, iteration concurrence 4 Notation of Activity Diagrams (1) action node Add a New rectangle with rounded Client corners and a meaningful name action edge Assign Staff (control flow) Contact open arrow 5 Notation of Activity Diagrams (2) initial node black circle Add a New decision node Client merge node diamond Assign Staff Contact guard condition [no campaign to add] in square brackets [campaign to add] Add New final node Campaign black circle in white circle 6 Tips on Activity Diagrams Multiple flows from an action are implicitly AND-ed Guard conditions do not have to be mutually exclusive, but it is advisable that they should be Decisions should be strictly nested, but a merge point can be combined with the following decision point 7 Notation of Activity Diagrams (3) fork node join node thick bar Add a New actions carried Client out in parallel Add New Assign Staff Campaign Contact 8 Notation of Activity Diagrams (4) Campaign::calculateCost class name can be shown followed getFirst (AdvertCollection::) by double colons in brackets (parentheses) beneath the action name getCost Operation Name (Advert:) can be shown after the colons, when different getNext (AdvertCollection::) with the action name [more adverts] [no more adverts] getOverheads (Campaign::) 9 Notation of Activity Diagrams (5) objects Campaign rectangle [Active] optionally shows the state of the object in square brackets Record completion object flows of a campaign open arrow Campaign [Completed] 10 Notation of Activity Diagrams (6) activity partitions (swimlanes) Campaign Accountant Client Manager vertical columns labelled with the Record Completion person, organization, of a campaign department or system responsible for the activities in Issue invoice that column Pay invoice Record client payment 11 Administrator Campaign Manager Add a New Client Assign Staff Contact :Client [no campaign to add] [New] [campaign to add] :Campaign Add New [Commissioned] Campaign [no staff to assign] [staff to assign] Assign Staff to Campaign [more staff to assign] [no more staff to assign] Author Reviewer Typesetter Printer Write Chapter Review Chapter Revise Chapter [book not complete] [book complete] Typeset Book Activity Diagram for producing a book. Correct Proofs Reset Book Print Book Author Reviewer Typesetter Printer Write Chapter Plan Chapter Write ChapterProduce First Draft Review Chapter Revise Draft Revise[not satisfied] Chapter [book not [satisfied] complete] Add Exercises [book complete] Add References Typeset Book to Bibliography More details can be shown on a Correct Proofs lower level. Reset Book Print Book Exercise: Supermarket Self-service Checkout 15 Take Home Messages Activity Diagrams Purpose Notation 16.