In my application the "System" capture screenshots and store it in local then in server,
at the same time count key stroke and mouse click and store it in server and local and same time also keep record of last two minutes and store it local and after random time store it server ,,, how i can display in sequence diagram the work of the system?
You can use Combined Fragment element of type parallel, or element coregion (alternative to combined fragmetn). These two elements define concurent execution in sequence diagrams.
Yes. This can be done in sequence diagrams. Not only parallel,You can show loops, breaks and if else etc in sequence diagrams.You have to learn combined fragment which is a sub-type of interaction fragment, to do that.
Related
I am new in doing an activity and currently, I am trying to draw one based on given description.
I enter into doubt on a particular section as I am unsure if it should be 'split'.
Under the "Employee", the given description is as follows:
Employee enter in details about physical damage and cleanliness on the
machine. For the cleanliness, there must be a statement to indicate
that the problem is no longer an issue.
As such, I use a foreach as a means to describe that there should be 2 checks - physical and cleanliness (see diagram in the link), before it moves on to the next activity under the System - for the system to record the checks.
Thus, am I on the right track? Thank you in advance for any replies.
Your example is no valid UML. In order to make it proper you need to enclose the fork/join in a expansion region like so:
A fork/join does not accept any sematic labels. They just split the control flow into several parallel ones which join at the end.
However, this still seems odd since you would probably have some control for the different inspections being entered. So I'd guess there's a decision which loops through multiple inspection entries. Personally I use regions only for handling interrupts. ADs are nice to a certain level. But sometimes a tabular text (like suggested by Cockburn) is just easier to write and read. Graphical programming is not the ultimate answer (unlike 42).
First, the 'NO' branch of the decision node must lead somewhere (at the end?).
After, It differs if you want to show the process for ONE or MULTIPLE inspections. But the most logical way is to represent the diagram for an inspection, because you wrote inspection without S ! If you want represent more than one inspection, you can use decision and merge node to represent loop that stop when there is no more inspection.
I have a situation where 3 options are presented to a user by a system:
Open PDF1.
Open PDF2.
Proceed.
The system instructs the user to read the PDFs, but doesn't enforce it.
So they're free to just click the proceed button and move on to the next screen.
I drew the following diagrams, but I feel like I've got it wrong somehow.
That's not correct this way. Your 2nd attempt isn't better at all. The bars will create parallel flows, but since you join them immediately it's actually a no-op in the first case. The bar will not be reached since it waits for 3 tokens where only one can actually arrive. In the 2nd case will never continue after the join since it only gets one token from the Provides... action but need 3 to continue.
Here's a cut part of what you need to do:
There's a merge node at first to capture the tokens coming from either the action on top or from the two left ones. After there there are two decisions going guarded to the actions at the left. The can be continued to the top (guard [read next]) or to the bottom (guard [acknowledge]). That way the user can repeat reading (or skip it completely) until he passes the Acknowledge action. There's a final merge node preceding that action.
Note that the read/ack guards should appear twice for each flow to make it a machine readable model. The texts here are just overlaid but a human can understand it anyway.
I have created a Sequence Diagram that I wish to convert to a Communication/Collaboration Diagram. I understand the conversion and the numbering process but I am wondering since my Sequence diagram have loops that are under the alt fragment, how is their numbering going to be in Communication Diagram?
Here a sample of my Sequence Diagram that have one of those loops:
Edit: What I want to know here is that since the loop is an IF situation, is it still OK to number those sequences? I don't think it would make logic if user's communication is, 1.0 Enter registered Username and Password, 2.0 Re-enter registered Username and Password...2.0 here is the IF loop situation
Communication diagram and sequence diagram represent the same interactions from a different angle. But the simplified graphical representation of the messages implies restrictions in the communication diagram when it comes to combined fragments.
In the communication diagram you can represent:
simple sequence of messages and nested messages, via the chronological numbering, e.g.: 1,2,3 and decimal numbering, e.g. 2.1, 2.2, 2.2.1
loops (loop operator in sequence diagram), using a * following the number. More specific looping specifications could follow the start between brackets e.g. *[1..n] or *[element in collection]. Your loop conditions are unspecified in the sequence diagram, so a * would do.
simple conditions (opt operator in sequence diagram), using a condition between brackets after the number e.g.[t>10]
In your example, we could therefore imagine: `
1: Enters username and passord
2: Check validity
2.1*: Mismatch of name or password // return message, not usual
2.2: Prompt user to re-enter credentials
2.3: Re-enter username and password
2.4: Re-check validity // missing in the SD in the loop
3: Verify user
4: USer verified
5: Display profile
Now there are two issues here: first, in your sequence diagram, there is a missing check validity in the loop. Second, I showed for simplicity all the messages, but in a communication diagram you would usually not sho return messages, to keep things simpler. So we'd have a slightly simpler model:
1: Enters username and passord
2: Check validity //message, return is implicit
3.1*[credentials invalid]: Prompt user to re-enter credentials
3.2: Re-enter username and password
3.3: Check validity
4: Read user
5: Display profile
Advice for the choice between SD and CD:
if you have many involved lifelines, either make several smaller SDs or opt for the CD.
if you have many message exchanges, especially between the same lifelines, prefer SD, because following the numbers on a CD is exponentially unintuitive with the increase of messages, and long lists of messages above the arrows look ugly.
if you have many combined fragments, or if you have more than loops and optionals, stay with SD.
If I have two frames in my GUI. (Assume 1st frame ="A" and 2nd frame="B").
when clicked on "A", it redirects to "B".
when Clicked on "B", it redirects to "A".
So it is continuously looping.
Is it possible to draw the Activity Diagram without adding the final node?
note: But anyone can click on the cross mark on top right corner and exit from the program. (Is that means I have to add final node to everywhere??)
You would model it with an interrupt flow like this:
The dashed boundary represents an interruptible region from where a flash-formed flow can exit at any time.
The Exit has not outgoing edges and thus ends the control flow. You might optionally add an outgoing flow to a flow final, though.
Alternatively, if there are many exceptions you could use this variant:
I doubt that is is really UML compliant, but as I say: "if it serves communication, it's fine". And from the context this looks rather evident.
Yes. An Activity ends when an Action ends and no other Action has the tokens it needs to start. You can find many fUML test cases that work like this, without explicit start and end nodes.
I can build a PID controller in the Haskell FRP library netwire using loop from the ArrowLoop instance provided for Wires.
I can also implement switching between controllers or between a controller and a manual input using switch.
How can I implement bumpless transfer, for example using the "tracking" strategy explained here (or in any number of control engineering articles/books)? Another strategy might be acceptable if it has good performance, but the tracking approach is appealing for my application because it also address anti-windup.
I'm having trouble squinting at the block diagram hard enough to make it look like the type of two (or one?) loop applications.
There are two loops in each diagram. It's helpful when finding loops to redraw the diagrams so that all of the inputs enter the same sides of all of the elements, all of the outputs leave the same other sides, and, if possible, minimize line crossings. In these diagrams, inputs enter the bottom, left, or top of an element, and outputs leave to the right.
The overall system has one loop, feeding the output of the process into the subtraction for the error comparison:
The control system has one loop, feeding the final control output after selection of controller (the PID controller or the manual control) into the tracking PID controller. The overall output is the Output on the far right.
The tracking PID controller has two loops. One is the feedback loop for the derivative. The loop for the derivative could disappear inside another component. The other loop feeds back the output of the PID controller into the comparison between the PID controller's output and the control output actually controlling the process. Note that the order of the P,D,and I branches is different in this diagram to remove the line crossings
Notice that if the tracking PID controller had its own Output connected to Track, the difference from the first subtraction would be 0, and the integration branch would be unchanged by the addition of 0.