Add Use Case diagram type

[karollewandowski]

Please do not +1 via comments. Click 👍 under this post.

Proposal

There is a lack of UML Use Case diagrams (or I failed to find it):
https://www.lucidchart.com/pages/uml-use-case-diagram

Use Cases

In the Unified Modeling Language (UML), a use case diagram can summarize the details of your system's users (also known as actors) and their interactions with the system

Screenshots

Source: https://www.lucidchart.com/pages/uml-use-case-diagram

Syntax

I have no knowledge of Mermaid conventions, but PlantUML can be a good inspiration:
https://plantuml.com/use-case-diagram

Implementation

This is a proposal which I'd love to see built into mermaid by the wonderful community.

[fidding]

This is very important, even making me want to give up mermaid

[paul-friedli]

I totally agree with the above comments : the "Use Case" diagram is probably one of the most important of all UML diagrams !

The "Use Case" diagram is usually the first to show in a projet, as it clearly presents the whole app/solution functionalities visually, without delving into technical details (as they are usually not know at this analysis stage).

Actors, resources, ... are all there on a single diagram focusing on "who" and "what" and not on "how".

Mermaid developers : that diagram availability would really be wonderful and super useful, since the whole project UML documentation could be done with mermaid.

[Angelles]

I would also love to have the use case diagram type.

[simone-boa-ideas]

I'll add my voice to the growing chorus 😉
I would love to have this option too. It's one of the most important diagrams for the documentation since it's perfect for aligning separate teams with different backgrounds on the features of a project.
At the moment I'm forced to implement it separately (with draw.io, exporting it as an image and importing it in GH), but this is not a scalable and maintainable solution. It would be much better if it had its own support in mermaid.

[kurt-o-sys]

yes please!

[luhui]

+1. Using flowcharts to simulate the effect of use cases for now

[ronnykwon]

+1 for this feature

[Flecart]

+1

[7agustibm]

+1

[lefkisamuel]

+1

[ramalhom]

+1

[haizenburg]

+1

[buudi]

+1

[smusali]

+1

[tienminhvy]

+1

[MiboraMinima]

+1

[kenchopa]

+1

[CamiloSinningUN]

+1

[osbyrne]

+1

[kkrafft1999]

+100
In our software development process everything starts with a use case diagram.

[iacobucci]

+1

[dholakashyap]

+1

[haibbo]

+1

[mstfkhazaal]

+1

[martinjurran]

+1

[Elphly]

+1

[svboyko]

+1

[ddsultan]

👍+1

[Dudelmoser]

+1

[LeiShi92]

+1

[guillemparrado]

+1

[Gerentedev]

+1

[root-kidik]

+1

[YusufLisawi]

+1

[renoon]

+1 👍

[AhmedMudkip]

+1

[fenilsonani]

+1

[chris-jongho-kim]

+1

[tierpel]

+1 👍

[UsamaEjaz0]

+1

[Supermarcel10]

+1

[karollewandowski]

Hi all. May I ask to not +1 this via comments? If you need it, please do it via emoji in the issue description. Receiving tens of +1 emails is quite annoying. Currently, there are 43 people following this issue, and all receive these comments.

Voting via emoji is better visible on https://github.com/mermaid-js/mermaid/issues?q=is%3Aissue+is%3Aopen+sort%3Areactions-%2B1-desc

Thank you for understanding.

[YB-A]

Hello @karollewandowski @simone-boa-ideas @fidding @paul-friedli you can use flow chart; try and adapt this :)
Bonus => you can add emoji

flowchart LR
    subgraph 'Online Shopping'
    uc1((View items))
    uc2((Make purchase))
    uc3((Complete Checkout))
    uc4((Log In))

    end
    customer[Customer👤]
    credit[credit_payment_service 💳]
    id[identity_provider🆔]
    sa[service_authentification🔑]
    pa[paypal💲]
    id--->uc1
    sa--->uc1

    customer----->uc1
    customer-->uc2
    uc2 -. include .-> uc1
    uc2 -. include .-> uc3
    credit---->uc3
    pa---->uc3
    customer--->uc4

yas in

[tom-craven]

+1

[enriquesaou]

+1

[Azevedo-Erick]

+1

[hgsgtk]

+1