Uml Activitydiagram

UML ACTIVITY Dr. Hoang Huu Hanh, OST – Hue University DIAGRAMS hanh-at-hueuni.edu.vn

Hue University

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Objectives To

read and write UML activity diagrams To know when and how to use activity diagrams

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Topics Processes

and process descriptions Activity diagram notation Activity diagram execution model Making activity diagrams

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Processes and Their Description

ss ssisisaa collection collectionof of related relatedtasks tasksthat that transforms transformsaaset set of of inputs inputsinto intoa

Process description notations describe design processes as well as computational processes we design. 

activity activitydiagram diagram shows showsactions actionsand andthe theflow flowof of control controland and data data betw bet

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Activities and Actions

An Anactivity activityisisaa non-atomic non-atomic task taskor or procedure proceduredecomposable decomposableinto into act ac

An Anaction actionisisaatask taskor or procedure procedurethat thatcannot cannotbe bebroken brokeninto intoparts. parts.

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Activity Graph Elements Do Laundry Sort Clothes Wash Whites

Wash Darks Dry Clothes Fold Clothes

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Execution Model  Execution

is modeled by tokens that are produced by action nodes, travel over action edges, and are consumed by action nodes.  When there is a token on every incoming edge of an action node, it consumes them and begins execution.  When an action node completes execution, it produces tokens on each of its outgoing edges.  An initial node produces a token on each e University outgoing edge when an activity 7 begins.

Branching Nodes Dry Clothes

Run Drier [still wet] [else] Fold Clothes

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Branching Execution If

a token is made available on the incoming edge of a decision node, the token is made available on the outgoing edge whose guard is true. If a token is available on any incoming edge of a merge node, it is made available on its outgoing edge. e University Guards must be mutually exclusive.

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Deadlock

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RunDrier cannot execute: when the activity begins, there is a token on the edge from the initial node but not on the other incoming 

Try to Dry Clothes Run Drier [still wet] [else] Fold Clothes

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Forking and Joining Nodes Do Laundry Sort Clothes

Wash Whites

Wash Darks

Dry Clothes Fold Clothes

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Forking and Joining Execution A

token available on the incoming edge of a fork node is reproduced and made available on all its outgoing edges. When tokens are available on every incoming edge of a join node, a token is made available on its outgoing edge. Concurrency can be modeled e University without these nodes. 12

Object Nodes 

Data and objects are shown as object nodes. Cruiser

Battleship [damaged]

Battlegroup

Destroyer [captured]

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Control and Data Flows Control

tokens do not contain data, object tokens do. A control flow is an activity edge that is a conduit for control tokens. A object flow is an activity edge that is a conduit for object tokens. Rules for token flow through nodes apply to both control and object tokens, except that object is extracted from consumed tokens and added to produced tokens. e University 14

Control and Data Flow Example Wash and Dry Clothes Wash Clothes Clothes [wet]

Run Drier

Clothes [still wet] [else] Fold Clothes

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Activity Parameters Activity

parameters are object nodes placed on activity symbol boundaries to indicate data or object inputs or outputs. Activity parameters contain the data or object name. Activity parameter types are specified in the activity symbol beneath the activity name.

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Activity Parameter Example FindMax a : int[1..*] max : int a

max = a[0] i=1

[else] [i < a.length] [else] [max < a.[i]] max = a[i]

max

i++

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he t n Activity Diagram Heuristics w o d ts c h t e i j b w . t o s d righ ion n t a to c l a o ft r t d n n e n u l a o co nd n s e w h i a t t o i i l a n v s. w t i  F age t a s c e a d e p a s c d d a e o r e n n h n a m o l a b p ect l o a N r w r j t  e b n g v o o o n l i f c r e . e a s h t t m se t a n a o e d b a N r  s a e h e e s p d n d i u e o rov t h ’ n n s w b. l l p o a D n t ca w e jo  y a o r e University l h . f e t h y e l v t t e re nod ren t u do a s r 18 n d e u

When to Use Activity Diagrams

When making a dynamic model of any process.



◦ Design processes (what designers do) ◦ Designed processes (what designers create)  During analysis During resolution

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Summary