Module 2 - Block Diagrams Part 2 Flashcards
Three types of associations
1. Reference
2. Shared
3.
Composite
what type of relationship is this ?
reference association
what type of relationship is this ?
composite association
what type of relationship is this ?
shared association
what does a 0..1 mean in the multiplicity of the diagram for the part property ?
that the part is optional or the reference is removable . remember the multiplicities do not have to match and represent two different design decisions
satellite is the _____ property
reference property
ecs is the ______ property
part property
what is the default multiplicity of a reference property in a composite association
0..1
which element is the super type
star sensor
which element is the subtype
star tracker
4 design decisions expressed in generalization representation
- inheritance
- abstraction
- substitutability
- extensibility
you can use a generalization between same classifiers .. block - block , value type - value type .. you are legally allows to use generalization between any classifier
inheritance - generalizations subtype will inheritance features from its _____
supertype
Generalization Principle
abstraction - means anything that is true for its supertype is true for its ______
subtypes
a supertype represents what is common for all its subtypes
Generalization Principle
substitutability - generalization means a subtype anywhere its _____ is required ..
note : if you dont see an element it in the diagram , it can be defined the model ..
supertype
Generalization Principle
a new subtype can be added without redesigning the new client that require the supertype when a new subtype can be added at anytime without rewiring the model. supertype is updated
is _____
extendability
Supplier , client , who is dependant , who is independant ?
supplier - independant , client is dependant “may change not a must “
dependency is a weak relationship only use it when ..
as a last source for traceability
if the requirement changes what may change ?
the interface and block as clients
a dependency can be created between
any two named elements
three common classifiers or element of definition that appear on BDD
1.
2.actors
3. constraint blocks
Value types
an Actor types what elements of usage ?
1 __________property
2 lifeline
reference
A block types what elements of usage ?
- part property
- reference property
- lifeline
- atomic flow port
- flow property
- object node
- Constraint ______
- constraint parameter
A value types what element of usages ?
1. object node
2.value property
3 port property
4. Atomic flow port
5
constraint parameter
review the table . elements of usage vs elements of definitions
constraint block types what element of usage ?
_________ property
constraint property
flow specification types what element of usage?
Non atomic flow port
signal types what three elements of usage ?
1.Atomic flow port
2. Flow property
3. Object Flow node
interface types what element of usage ?
standard port
association types what element of usage ?
connector
activity types what element of usage
call behavior action
state machine types what element of usage
call behavior action
interaction (element of definition ) types _______behavior action
call
actors define a type of structure that is outside the boundary of your system and interfaces with the system. Three examples are
- human operator
- inanimate object
external interface
An actor cannot own any features ( structural / behavior) because
that’s language law for sysml .
treat actors like white box or black boxes ?
black boxes . You dont care whats the external interfaces are in the the actor element of definition . if you add part property to actors this breaks the language law for sysml exposing its parts .
** begin in the singular
Interpret the reference association . A single instance of the system operator could be connected to one or more instances of _______ at a time
Delsat-77 satellite
** begin in the singular
A single instance of DelSat-77 satellite could be connected to one or more instances of ______________ at a time
system operator
value type defines a numerical value or a quantity of _____
interest
what kind of value type is this and why ?
structured value type ; because it is a composition of other value types
what kind of value type is this and why ?
primitive value type ; because it represents one value type
what kind of value type is this and why ?
enumeration - define literals ( options ) that a user can pick from
list 5 predefined value types
- string
- boolean
- real
- complex
- integer
ecs - part property that is a role played internal to satellite. its owner is the classifier at the composite end ___
satellite
Interpret the ttof label
.ttof is not a part property but a constraint property
ttof is sitting next to a constraint block so its typed by a constraint block
what are the constraint properties
tos and ttof
which diagram shows the constraint properties bounding to the constraint block
parametric diagram connects the two equations together. This cannot be done in a BDD
A contraint block can be a composition of other constraint blocks
True
what does * mean in the multiplicity ?
0..* zero or more instances
a compositie associate from a block into itself. Does not mean the block is composed of itself. An association expresses system structure not connection between elements.
associations do not convey name space. They say nothing about where the elements are nested in the model .
