Module 5 - Activity Diagrams Part 1 Flashcards
Three kinds of behaviors in Sysml are
1. activity
2. state machines
3. __________
Interaction
Three kinds of behavioral diagrams in sysml are
1. activity diagram
2.
3. state machine diagram
sequence diagram
T/F Activity and activity diagrams are synonyms
False
activity - behavior / element of definition
activity diagram - behavioral diagrams
T/F Is it legal to create multiple views of a model element ?
True
a block can have 1 or more activity nested under it
what is the namespace of this diagram ?
Execute Hohmann transfer is an activity which contains all the elements
two top level categories that an activity can own
1. Nodes
2 .
Edges
Three kinds of nodes that appear in an activity diagram
1. actions node ( oval actions )
2.
3. control node ( fork node , decision node , initial node ,merge node , activity final , flow final )
object node ( square actions)
Two kinds of edges that appear in an activity diagram
1. object flow ( solid arrows)
2.
control flow ( dashed arrows)
two kinds of tokens that can flow through an activity
- object tokens
2.
control tokens
object flows carry object ____
control flows carry control ____
tokens
what does an object token represent ( solid arrow) ?
an instance of an object of going from one action going into another action
object - matter , energy or data
object node is typed by
1. value type
2. signal
3.
block
object token can represent an instance of a block , value type or signal
what is the name of the object token going into the VC action ?
transfer command
what is the name of the input object token of “Generate response with invalid status” action ?
Boolean
when “generate command action is executed it will produce a command response
True / False
An object token will be an instance of that type of Command response
True
each object token that traverses an object flow represents an instance of a type
- value type
- block
3
signal
What does a control token represent ? ( dashed arrow) at execution time
it represents one action must come to an end in order for one action to start
a control token does not represent an object of any kind. Therefore its not typed in a node
How many tokens will this Generate response with “Valid Command” Status action produce - look at output pins
two
1 command response and 1 control token
What kind of action is this ?
opaque action or basic action
An activity contains a set of ____________ contained within it
action
what is the name of the execution ( behavior) being called ?
what is the action name ?
Action name : enter transfer orbit
Execution (behavior) name : Fire Thrusters
When does an action start
- the activity that owns the action is currently
executing
When does an action start
- A control token arrives on each of the incoming control
flows
When does an action start
- A suffient number of object tokens arrive on each of the incoming object flows to satisfy lower
mulitplicity
three kinds of object nodes
- basic
2.
3 .activity parameter node
pin
note : pins and activity parameters are optional to add in the diagram.
Basic object node appears between two
actions
activity parameter nodes appears on the _____ of the FRAME
boarders
Note : activity parameter represents input and output of the activity as a whole.
T/F
Object nodes act like a buffer to hold the object tokens
All object nodes are elements of usage
True
the object token stay in the object node till an action downstream requires them to move to another action
How would you interpret this model ?
each time the action ma comes to an end it produces
1 km object token
what narrative is shown in this activity diagram ?
each time action ma finishes executing it will produce 1 object token of type km
which travels thru an object flow arriving on another action .. then the following action
action requires 1 token of type km a new execution of the action will start
each time action ma finishes it will produce anywhere from 0 to 10 token flows as a batch
what will happen if 2 tokens are produced ? how many executions will it this will result in two executions of the __________ action being executed because the min token required is 1 km token
currentOrbitRadius
action ma can execute and produce 0 tokens
0 tokens means that the pin is
optional
what does the multiplicity convey on the input pin ?
the action requires a min of 2 tokens to be consumed by the execution
if a batch of 4 tokens arrive ,that starts 1 execution of the action
nonstreaming behavior refers
to a token that emerges when an action finished execution , every time the lower bound is satisfied a execution starts the upstream action must finish before the downstream action
streaming behavior on a pin refers to
the upstream action doesn’t have to finish executing in order to have a token appear on the pin
streaming input pin will be used by the current action , they would not wait for the action to
finish
difference between what types a control token and object token
block , value or signal types a object token
what types a control token ?
nothing
For each input pin all the ( upper or lower ) multiplicity must be satisfied for an action to start ?
lower multiplicity
when will action ma will start executing when the control tokens arrives? object tokens arrives ?
the control token arrives.
it does not need an object token because its multiplicity is 0
when will action vc begin executing ?
it has an incoming control flow and an input pin ( default multiplicity is 1)
the action vc needs 1 object token AND a control token in order to start a new execution
when will action rs start execution ?
It has an input pin ( 0 multiplicity )
has no input control tokens
the action rs will start executing the moment the owning activity starts executing
a1 has no incoming edges , control flows or any input ..
when will action a1 start executing
a1 doesn’t need any control token
a1 doesn’t have any input pins
action a1 will begin executing once the owning action is executing
common mistake modelers make is modeling a loop wrong ..
what is the design error ?
the orbitRadiusUpdated needs a control token to arrive from the previous action and the action that comes after the decision object node
deadlock - an action that will wait on multiple tokens that will arrive
what does the streaming output pin on action 2 convey ?
it has to complete execution before
it produces a token going to the next action
