Papyrus Sequence Diagram Examples
Eclipse Papyrus Create Sequence Diagram
Papyrus Sequence Diagram Maker

Visual Paradigm offers a pretty good free tool to draw not only sequence diagrams but also all UML 2.x diagrams. Download Visual Paradigm Community Edition Cheers!
Draw a sequence diagram in Papyrus to represent the scenario, given your decisions. As you may have found in last week's lab, or finishing it later, there are quite a few things to know about sequence diagrams in Papyrus. For example: to create lifelines, the easiest way is to drag a class from the model explorer to the SD canvas.

I created simple sequence diagram in Papyrus. It has lifeline1, lifeline2, and one async message from lifeline1 to lifeline2. When i delete message from diagram (it stays in model), and try to dra. Robustness diagrams often act as bridge from use cases to other models. For example, it is quite common to create sequence diagrams which represent the detailed design logic required to support the use case. It is also common to focus on the user interface for your system, perhaps via prototyping or better yet just getting right into the 'real.

This video is the third in a series of three videos which, next to modelling, talks about the Software Design concept named 'Robustness Analysis'.

Combined fragment is an interaction fragment which defines a combination (expression) of interaction fragments. A combined fragment is defined by an interaction operator and corresponding interaction operands. Through the use of combined fragments the user will be able to describe a number of traces in a compact and concise manner.

Combined fragment may have interaction constraints also called guards in UML 2.4.

Interaction operator could be one of:

alt - alternatives
opt - option
loop - iteration
break - break
par - parallel
strict - strict sequencing
seq - weak sequencing
critical - critical region
ignore - ignore
consider - consider
assert - assertion
neg - negative

Interaction Constraint

An interaction constraint is a constraint used in interactions - a Boolean expression that guards an operand in a combined fragment.

An interaction constraint is shown in square brackets covering the lifeline where the first event occurrence will occur, positioned above that event, in the containing interaction or interaction operand.

UML 2.4 often refers to interaction constraint as a guard.

Alternatives

The interaction operator alt means that the combined fragment represents a choice or alternatives of behavior. At most one of the operands will be chosen. The chosen operand must have an explicit or implicit guard expression that evaluates to true at this point in the interaction.

An implicit true guard is implied if the operand has no guard.

An operand guarded by else means a guard that is the negation of the disjunction of all other guards. If none of the operands has a guard that evaluates to true, none of the operands are executed and the remainder of the enclosing interaction fragment is executed.

Call accept() if balance > 0, call reject() otherwise.

Option

The interaction operator opt means that the combined fragment represents a choice of behavior where either the (sole) operand happens or nothing happens. An option is semantically equivalent to an alternative combined fragment where there is one operand with non-empty content and the second operand is empty.

Papyrus Sequence Diagram Examples

Loop

The interaction operator loop means that the combined fragment represents a loop. The loop operand will be repeated a number of times. The loop construct represents a recursive application of the seq operator where the loop operand is sequenced after the result of earlier iterations.

UML 2.4 specification provides weird description of the loop operator with odd examples. I will try to extract here some sense from that.

Loop could be controlled by either or both iteration bounds and a guard.

Loop operand could have iteration bounds which may include a lower and an upper number of iterations of the loop. Textual syntax of the loop is:

loop-operand ::= loop [ '(' min-int [ ',' max-int ] ')' ]
min-int ::= non-negative-integer
max-int ::= positive-integer | '*'

Srt-translator. If loop has no bounds specified, it means potentially infinite loop with zero as lower bound and infinite upper bound.

Potentially infinite loop.

If only min-int is specified, it means that upper bound is equal to the lower bound, and loop will be executed exactly the specified number of times.

If max-int is specified, it should be greater than or equal to min-int. Loop will iterate minimum the min-int number of times and at most the max-int number of times.

Besides iteration bounds loop could also have an interaction constraint - a Boolean expression in square brackets. To add to the other confusions, UML 2.4 also calls both of them guards.

UML tries to shuffle the simplest form of for loop and while loop which causes weird UML 2.3 loop semantics on p.488 [UML 2.3 - Superstructure]: 'after the minimum number of iterations have executed and the Boolean expression is false the loop will terminate'. This is clarified - though with opposite meaning - on the next page as 'the loop will only continue if that specification evaluates to true during execution regardless of the minimum number of iterations specified in the loop.'

We may guess that as per UML 2.3, the loop is expected to execute
minimum 5 times and no more than 10 times.
If guard condition [size<0] becomes false loop terminates
regardless of the minimum number of iterations specified.
(Then why do we need that min number specified?!)

Break

The interaction operator break represents a breaking or exceptional scenario that is performed instead of the remainder of the enclosing interaction fragment.

A break operator with a guard is chosen when the guard is true. In this case the rest of the directly enclosing interaction fragment is ignored. When the guard of the break operand is false, the break operand is ignored and the rest of the enclosing interaction fragment proceeds.

A combined fragment with the operator break should cover all lifelines of the enclosing interaction fragment.

Note, UML allows only one level - directly enclosing interaction fragment - to be abandoned. This could become really annoying if double loop or loop with other combined fragments should be broken.

UML 2.3 states that when break operand has no guard, the choice between the break operand and the rest of the enclosing interaction fragment is done 'non-deterministically' which most likely means 'unpredictable'. Don't use break without guard.

Parallel

The interaction operator par defines potentially parallel execution of behaviors of the operands of the combined fragment. Different operands can be interleaved in any way as long as the ordering imposed by each operand is preserved.

Set of traces of the parallel operator describes all the possible ways or combinations that occurrence specifications of the operands may be interleaved without changing the order within each operand.

Search Google, Bing and Ask in any order, possibly parallel.

Parallel combined