Type out your workflow in plain language and Figviz will assemble a standards-compliant UML activity diagram for you. Great for mapping business processes, modeling software behavior, and communicating system design to any audience.
Real workflows rendered as UML activity diagrams. Use one as a starting point or generate your own above.
User Login Flow
Step-by-step login activity diagram showing credential validation decisions, an optional two-factor authentication branch, an account lockout path after repeated failures, and a session-creation action on success.
loginauthenticationsecurity
Order Processing Workflow
E-commerce order-processing activity diagram with a fork bar kicking off concurrent payment verification and inventory checks, a join bar to synchronize results, and role-based swimlanes for Customer, System, and Warehouse.
orderecommerceparallel
CI/CD Pipeline
Continuous integration and delivery activity diagram with a fork/join pair running unit and integration tests simultaneously, a quality-gate decision, staging deployment, manual approval, and production release.
cicddevopspipeline
Patient Admission Process
Hospital admission activity diagram partitioned into Reception, Nursing, and Doctor swimlanes, covering intake registration, concurrent triage and insurance verification, initial examination, and bed assignment or outpatient referral.
healthcareadmissionhospital
ATM Withdrawal Process
ATM withdrawal activity diagram tracing card insertion through PIN verification with a three-attempt retry loop, amount selection, balance check, cash dispensing, and an optional receipt-printing branch.
atmbankingwithdrawal
Code Review Process
Pull-request review activity diagram with Developer and Reviewer swimlanes, automated linting and test checks running in parallel, a review-and-feedback cycle, approval gate, and final merge to main.
code-reviewgitdevelopment
Prompt templates you can copy
Start with one of these examples, then adapt the subject, labels, data, or layout for your own use.
User Login Flow
Step-by-step login activity diagram showing credential validation decisions, an optional two-factor authentication branch, an account lockout path after repeated failures, and a session-creation action on success.
Create a UML activity diagram for a user login flow. Start with Enter Credentials, decision node for Valid Credentials, branch to Show Error and increment attempt counter on failure, decision node for Max Attempts Reached leading to Lock Account, branch to 2FA Required decision, Send OTP and Verify OTP actions, finally Create Session and Redirect to Dashboard. Use standard UML notation with initial node, decision diamonds, action rounded rectangles, and final node, white background
Order Processing Workflow
E-commerce order-processing activity diagram with a fork bar kicking off concurrent payment verification and inventory checks, a join bar to synchronize results, and role-based swimlanes for Customer, System, and Warehouse.
Create a UML activity diagram for an e-commerce order processing workflow with swimlanes for Customer, System, and Warehouse. Customer places order, System receives it, fork bar splits into parallel activities: Verify Payment and Check Inventory, join bar synchronizes, decision node for Both Passed, branch to Confirm Order and Notify Warehouse or Cancel Order and Refund, Warehouse picks, packs, and ships, final node. Standard UML notation, white background
CI/CD Pipeline
Continuous integration and delivery activity diagram with a fork/join pair running unit and integration tests simultaneously, a quality-gate decision, staging deployment, manual approval, and production release.
Create a UML activity diagram for a CI/CD pipeline. Start with Code Commit, trigger Build step, fork bar for parallel Unit Tests and Integration Tests, join bar, decision node for All Tests Pass, branch to Code Review on pass or Notify Developer on fail, after review decision for Approved, Deploy to Staging, Run Smoke Tests, decision Smoke Tests Pass, Manual Approval gate, Deploy to Production, final node. Standard UML notation, white background
Patient Admission Process
Hospital admission activity diagram partitioned into Reception, Nursing, and Doctor swimlanes, covering intake registration, concurrent triage and insurance verification, initial examination, and bed assignment or outpatient referral.
Create a UML activity diagram for a hospital patient admission process with swimlanes for Reception, Nurse, and Doctor. Reception registers patient and verifies insurance, fork bar for parallel Insurance Verification and Triage Assessment by Nurse, join bar, Doctor performs Initial Examination, decision node for Admission Required, branch to Assign Bed and Create Care Plan or Schedule Outpatient Follow-up, final node. Standard UML notation, white background
Understanding UML Activity Diagrams
A UML activity diagram is a behavioral model that captures the dynamic flow of actions, branching decisions, and concurrent tasks within a system or business process. Defined in the Unified Modeling Language specification, activity diagrams have earned their place as one of the most practical UML diagram types because they communicate step-by-step logic in a form that engineers, analysts, and stakeholders can all read without prior UML training. Compared with basic flowcharts, activity diagrams introduce purpose-built constructs: fork/join bars for parallelism, partitions (swimlanes) for responsibility assignment, and signal-event nodes for inter-process coordination. These additions make them far more expressive when modeling real-world systems where steps overlap and multiple actors collaborate.
Core Symbols and Notation
Every element in an activity diagram has a precise meaning in the UML specification. The initial node (a solid filled circle) marks where execution begins; the activity final node (a circle with a filled dot inside) marks the end. Action nodes (rounded rectangles) represent individual tasks or steps. Decision nodes (diamonds) introduce conditional splits, with guard expressions written on outgoing edges. Merge nodes (also diamonds) reunite alternative paths into a single flow. Fork bars and join bars (thick lines) split one flow into concurrent threads and then wait for all threads to finish before continuing. Object nodes (plain rectangles) represent data passed between actions, and directed arrows define the order of execution across all these elements.
How Swimlanes Assign Responsibility
Swimlanes, formally called activity partitions, divide the diagram canvas into vertical or horizontal bands, each representing a distinct actor, team, or system. Placing an action inside a lane makes it immediately clear who owns that step, which is invaluable for cross-functional processes where multiple parties hand work back and forth. An order-fulfillment diagram, for example, might partition responsibility across a Customer, an Order Service, a Payment Gateway, and a Fulfillment Center. When a flow arrow crosses a lane boundary, it signals a handoff between parties. This responsibility-mapping capability elevates activity diagrams from simple process maps into tools that expose coordination gaps and ownership ambiguities in real workflows.
Decision Nodes and Guard Conditions
Decision nodes split a single incoming flow into two or more outgoing paths based on Boolean guard conditions. Guards are written directly on outgoing edges inside square brackets, for example [balance >= amount] or [approved = true]. For the diagram to be logically sound, guards on all outgoing paths from a single decision node must be mutually exclusive and collectively exhaustive so that exactly one path fires. Merge nodes then bring the alternative paths back into a single flow downstream. Chaining decision and merge node pairs lets you model nested conditional logic of any depth. Figviz reads your plain-text description and automatically generates correctly paired decision/merge nodes with well-labeled guard conditions.
Modeling Concurrency with Fork and Join
Fork bars split one incoming flow into two or more outgoing threads that run simultaneously. Join bars then wait for every incoming thread to complete before allowing the single outgoing flow to continue. This pairing is the correct UML mechanism for representing true parallelism, such as simultaneous payment authorization and inventory reservation during checkout, or concurrent unit and integration test runs in a CI pipeline. Mismatched fork/join pairs are a common modeling mistake that implies incorrect timing assumptions; Figviz ensures every fork has a corresponding join and that all concurrent threads are properly synchronized in the generated output.
Picking a Visual Style
, Modern Clean: crisp strokes with tasteful color accents. Best suited for slide decks, product docs, and stakeholder walkthroughs where polish matters.
, Technical Standard: strict UML 2.5 notation with formal text labels. The right choice for software specifications, architecture reviews, and academic submissions.
, Minimalist: thin lines, restrained palette, and generous white space. Ideal for embedding inside reports, wikis, or README files where the diagram should not compete with surrounding text.
Picking a Layout
, Standard Flow: top-to-bottom single-column arrangement. Works well for linear workflows with a single actor and no responsibility handoffs.
, With Swimlanes: horizontal or vertical partitions grouping actions by actor or system. Essential whenever "who does what" needs to be visible at a glance.
, Compact: space-efficient arrangement that packs more steps into a smaller area while keeping every node label readable.
Picking a Color Scheme
, Professional Blue: consistent blue highlights on action nodes and dark-gray connectors and text. Universally readable and appropriate for almost any professional setting.
, Categorical Colors: distinct hues assigned per swimlane, action type, or decision branch. Particularly helpful in complex multi-actor diagrams where visual separation speeds comprehension.
, Monochrome: black, white, and gray only. The go-to choice for printed technical reports, accessibility requirements, or any context where color reproduction is unreliable.
Frequently asked questions
Figviz provides a free AI-powered activity diagram generator that converts plain-text process descriptions into standards-compliant UML diagrams. Describe your workflow, choose a style and layout, and Figviz handles the notation, including decision nodes, fork/join bars, and swimlanes. No manual drawing required and no UML expertise needed, making it practical for developers, business analysts, and students alike.