Flowchart Best Practices

Creating effective flowcharts is both an art and a science. This guide teaches you industry-standard best practices for creating clear, professional, and ISO 5807 compliant flowcharts that communicate processes effectively.

What You'll Learn

• ISO 5807 standard compliance and why it matters
• Layout principles for readable flowcharts
• Proper shape selection and usage
• Labeling conventions and naming best practices
• Visual hierarchy and color coding strategies
• Common mistakes and how to avoid them
• Accessibility considerations
• Professional documentation standards

Why Best Practices Matter

Well-designed flowcharts:

• Communicate clearly - Anyone can understand the process at a glance
• Reduce errors - Consistent conventions prevent misinterpretation
• Save time - Standard patterns are familiar to readers
• Look professional - Proper formatting reflects quality work
• Meet standards - ISO compliance ensures universal understanding

ISO 5807 Standard Compliance

ISO 5807 is the international standard for flowchart symbols. DiagramKit.AI implements all standard shapes with proper geometries and colors.

Why Follow ISO 5807?

1. Universal Recognition - ISO symbols are understood globally
2. Professional Credibility - Standards compliance demonstrates expertise
3. Legal/Compliance - Some industries require ISO-compliant documentation
4. Cross-Team Communication - Standard symbols work across departments
5. Tool Compatibility - ISO shapes import/export reliably

Core ISO 5807 Symbols

DiagramKit.AI provides 19 ISO-compliant shapes. Here are the essential ones:

| Shape | Name | Use Case | ISO Geometry | |-------|------|----------|--------------| | Start/End | Terminator | Process boundaries | Rounded rectangle (stadium) | | Process | Action/Operation | Any process step | Rectangle | | Decision | Conditional | Yes/no questions | Diamond | | Data I/O | Input/Output | Data entering/leaving | Parallelogram | | Database | Data Store | Database operations | Cylinder | | Document | Document | Reports, forms | Rectangle with wavy bottom | | Connector | On-page connector | Connect distant parts | Circle | | Off-Page Connector | Off-page reference | Multi-page flows | Pentagon |

Layout Principles

1. Flow Direction

Standard: Top-to-bottom, left-to-right flow

Good:

Start
  ↓
Process A
  ↓
Process B
  ↓
End

Bad:

End
  ↑
Process B
  ↑
Process A
  ↑
Start

Why: Top-to-bottom matches natural reading direction and Western cultural norms. Readers expect processes to flow downward.

2. Consistent Spacing

Use consistent spacing between shapes for professional appearance.

Best Practices:

• Vertical spacing: 60-80 pixels between shapes
• Horizontal spacing: 100-120 pixels for parallel processes
• Grid alignment: Use DiagramKit.AI's 16px snap grid
• White space: Don't crowd shapes - use generous spacing

3. Alignment

Align shapes to create visual order.

Alignment Rules:

• Center-align shapes in a vertical sequence
• Top-align shapes in a horizontal sequence
• Align decision branches symmetrically when possible
• Use grid lines as alignment guides

Good:

    Process A
        ↓
    Decision
    ↙      ↘
Process B  Process C
    ↓        ↓

Bad:

Process A
    ↓
  Decision
  ↙     ↘
Process B    Process C
  ↓       ↓

4. Crossing Lines

Minimize or eliminate crossing connection lines.

Strategies:

• Rearrange shapes to avoid crossings
• Use connectors for complex flows (small circles)
• Split into multiple diagrams if too complex
• Use off-page connectors for multi-page flows

Good: Lines never cross

Bad: Lines cross multiple times, creating confusion

5. Line Routing

Connection lines should be clear and minimal.

Best Practices:

• Minimize bends - Straight lines or simple L-shapes are best
• Avoid diagonal lines unless necessary
• Use 90-degree angles for clean appearance
• Don't route through shapes - go around them

Shape Selection Guide

Choose the right shape for each process element.

Start/End Shapes

Use for:

• Process beginning (labeled "Start")
• Process ending (labeled "End")
• External entities (labeled with entity name)

Don't use for:

• Middle process steps (use Process shape)
• Decisions (use Decision shape)

Process Shapes

Use for:

• Actions or operations (e.g., "Calculate Total")
• Transformations (e.g., "Convert to JSON")
• Assignments (e.g., "Set Status to Active")
• Function calls (e.g., "Call Authentication API")

Label with:

• Action verbs (Calculate, Transform, Send, Process)
• Clear, specific descriptions
• Present tense

Good Labels:

• "Validate User Input"
• "Send Confirmation Email"
• "Update Database Record"

Bad Labels:

• "Validation" (noun, not verb)
• "Email" (too vague)
• "Update" (missing context)

Decision Shapes

Use for:

• Yes/no questions
• True/false conditions
• Multiple choice (with 3+ branches)

Label with:

• Questions ending in "?"
• Boolean conditions
• Clear, testable criteria

Good Labels:

• "Is User Authenticated?"
• "Payment Successful?"
• "Age > 18?"

Bad Labels:

• "Check Authentication" (action, not question)
• "Payment" (not a question)
• "Age" (missing comparison)

Branch Labels:

• Label decision branches: "Yes/No", "True/False", or specific values
• Place labels near the decision shape, on the connecting line
• Be consistent with terminology throughout the diagram

Data I/O Shapes

Use for:

• User input (forms, keyboards)
• System output (displays, reports)
• Data entering/leaving the process
• External data sources

Examples:

• "Get User Login Credentials"
• "Display Welcome Message"
• "Read Configuration File"
• "Output Report PDF"

Database Shapes

Use for:

• Database queries (SELECT, INSERT, UPDATE, DELETE)
• Data storage operations
• Cache access
• Persistent data operations

Examples:

• "Query User Records"
• "Save Order to Database"
• "Check Cache"

Document Shapes

Use for:

• Report generation
• Form creation
• Document output
• Physical paperwork

Examples:

• "Generate Invoice PDF"
• "Print Receipt"
• "Create Audit Log"

Labeling Conventions

Clear labels are essential for flowchart comprehension.

General Label Guidelines

1. Be Specific - Avoid vague terms

   • Good: "Validate Email Format"
   • Bad: "Check"

2. Use Action Verbs - For process shapes

   • Good: "Calculate Discount"
   • Bad: "Discount Calculation"

3. Keep It Concise - 2-6 words ideal

   • Good: "Send Email Notification"
   • Bad: "Send an email notification to the user's registered email address"

4. Use Consistent Terminology - Pick terms and stick with them

   • Good: Always "User" or always "Customer"
   • Bad: Mixing "User", "Customer", "Client" in same diagram

5. Avoid Technical Jargon - Unless for technical audiences

   • For business: "Check Payment Status"
   • For developers: "Query payment_status field"

Title and Description

Every flowchart should have:

• Title - Clear, descriptive name
• Description - Brief purpose statement
• Version/Date - For documentation tracking
• Author - Who created it

Example:

Title: Customer Order Processing Workflow
Description: Handles customer orders from receipt through fulfillment
Version: 2.1
Updated: 2025-01-13
Author: Operations Team

Visual Hierarchy and Styling

Color Coding

DiagramKit.AI shapes use ISO-compliant default colors, but you can add semantic color coding.

Color Strategies:

1. By Process Stage

   • Blue: Input/Start
   • Green: Processing
   • Yellow: Decisions
   • Red: Errors/Exceptions
   • Gray: End states

2. By Department (for cross-functional flowcharts)

   • Blue: Sales
   • Green: Operations
   • Purple: Support
   • Orange: Finance

3. By Priority

   • Red: Critical path
   • Yellow: Secondary
   • Gray: Optional

Size and Emphasis

• Keep shapes uniform - Same size for same types
• Use larger shapes for major processes (sparingly)
• Use smaller shapes for minor details
• Don't make everything important - Emphasis loses meaning

Common Mistakes to Avoid

1. Too Much Detail

Problem: Flowchart becomes overwhelming and hard to read

Solution:

• Create high-level flowchart first
• Add detailed sub-process flowcharts separately
• Link them using off-page connectors
• Follow the "7±2 rule" - aim for 5-9 shapes per diagram section

2. Missing Decision Outcomes

Problem: Decision shape has unlabeled or missing branches

Solution:

• Always label decision branches (Yes/No, True/False)
• Account for all possible outcomes
• Handle error cases explicitly

Bad:

Valid Input? → Process

Good:

Valid Input? → Yes → Process
             → No → Show Error

3. Dead Ends

Problem: Process paths don't lead to End shape

Solution:

• Every path must reach an End shape
• Or explicitly show continuation (off-page connector)
• No dangling processes

4. Ambiguous Flow

Problem: Multiple arrows from shape without clear decision

Solution:

• Use Decision shape for branching
• Don't branch from Process shapes
• Make conditional logic explicit

Bad:

Process A → Process B
         → Process C

Good:

Process A → Decision → Yes → Process B
                    → No → Process C

5. Inconsistent Direction

Problem: Flow goes in multiple directions randomly

Solution:

• Maintain top-to-bottom, left-to-right flow
• Use connectors if you must change direction
• Keep flow direction predictable

6. Overly Complex Diagrams

Problem: Too many shapes, lines, and decision points

Solution:

• Break into multiple diagrams
• Create hierarchical flowcharts
• Use sub-process shapes to abstract complexity
• Maximum 15-20 shapes per diagram

7. Poor Label Quality

Problem: Labels are vague, inconsistent, or missing

Solution:

• Follow labeling conventions (above)
• Review all labels for clarity
• Have someone else review for understanding
• Use consistent terminology

Advanced Best Practices

Swimlanes (Coming Soon)

Swimlanes organize flowcharts by role or department.

Use for:

• Cross-functional processes
• Multi-team workflows
• Showing responsibility assignment

Structure:

• Horizontal lanes for each role
• Process flows across lanes
• Shows handoffs between teams

Sub-Processes

Use sub-process abstraction for complex workflows.

Pattern:

1. Main flowchart shows high-level steps
2. Create separate flowcharts for complex steps
3. Name sub-process with same label as main flowchart step
4. Use off-page connectors to link

Example:

Main: Order Processing
  → Validate Order → Process Payment → Ship Order

Detail: Process Payment (separate flowchart)
  → Check Card → Authorize → Capture → Handle Errors

Exception Handling

Always show error paths explicitly.

Best Practices:

• Every operation that can fail needs an error branch
• Show error handling processes
• Route errors to appropriate endpoints (retry, log, alert)
• Don't hide failure cases

Example:

API Call → Success? → Yes → Continue
                   → No → Log Error → Retry? → Yes → API Call
                                             → No → Alert Admin

Loops and Iterations

Show iterative processes clearly.

Best Practices:

• Use backward arrows to show loops
• Add loop condition as a decision
• Prevent infinite loops with exit conditions
• Consider using "For Each" or "While" labels

Example:

For Each Item → Process Item → More Items? → Yes → (back to start)
                                          → No → Continue

Documentation Standards

Flowchart Documentation Checklist

• [ ] Title clearly describes the process
• [ ] Description explains the purpose
• [ ] All shapes use correct ISO 5807 types
• [ ] Labels are clear and action-oriented
• [ ] All decision branches are labeled
• [ ] Every path reaches an End shape
• [ ] Consistent spacing and alignment
• [ ] No crossing lines (or minimal)
• [ ] Top-to-bottom, left-to-right flow
• [ ] Error cases are handled
• [ ] Version and date are included
• [ ] Someone else can understand it without explanation

Review Process

Before finalizing a flowchart:

1. Self Review - Walk through each path
2. Peer Review - Have colleague review for clarity
3. Stakeholder Review - Verify with process owners
4. User Testing - Can intended audience understand it?

Maintenance

• Update regularly - Keep flowcharts current with actual processes
• Version control - Track changes over time
• Archive old versions - Maintain history
• Review annually - Even stable processes change

Accessibility Considerations

Make flowcharts accessible to all users.

Best Practices

1. Don't rely on color alone - Use shapes and labels
2. Use clear labels - Screen readers need descriptive text
3. Maintain contrast - Text should be readable
4. Provide text descriptions - Summary for screen readers
5. Use standard shapes - Familiar to all users
6. Export to accessible formats - SVG and PDF support accessibility

Alt Text

When sharing flowcharts, provide text descriptions:

Example:

Alt Text: User login flow flowchart showing: Start, Display Login Form,
User Enters Credentials, Validate Credentials, decision point for Valid
Credentials with Yes path leading to Login Success and No path leading
to Show Error Message, then End.

Industry-Specific Considerations

Software Development

• Use technical terminology appropriate for developers
• Include error handling prominently
• Show API calls, database operations explicitly
• Consider asynchronous operations
• Document edge cases

Business Processes

• Use business language, avoid technical jargon
• Show decision makers explicitly
• Include approval workflows
• Consider compliance requirements
• Document manual vs. automated steps

Healthcare

• Follow HIPAA guidelines for sensitive data
• Show privacy checkpoints
• Document consent processes
• Include audit trail considerations
• Show emergency procedures

Manufacturing

• Include quality checkpoints
• Show inspection processes
• Document safety procedures
• Include equipment/machinery
• Show material flow

Professional Tips

Examples: Good vs. Bad

Example 1: Process Labels

Bad Flowchart:

Start → Input → Check → Database → Output → End

Problems:

• Labels are vague
• Wrong shape types (Input/Output aren't shapes)
• No decision logic shown

Good Flowchart:

Start
  ↓
Get User Credentials (Data I/O)
  ↓
Validate Format (Process)
  ↓
Format Valid? (Decision)
  ├→ Yes → Query Database (Database)
  |          ↓
  |        User Found? (Decision)
  |          ├→ Yes → Display Welcome (Data I/O) → End
  |          └→ No → Show Not Found (Data I/O) → End
  └→ No → Show Format Error (Data I/O) → End

Improvements:

• Specific, action-oriented labels
• Correct shape types
• All decision paths shown and labeled
• Every path reaches End

Example 2: Layout

Bad Layout:

        Start
          ↓
    Process A ←────┐
          ↓        |
    Process B      |
       ↙  ↘       |
Process C Process D
       ↘  ↙        |
    Decision       |
       ↓ Yes       |
    Process E ─────┘
       ↓ No
        End

Problems:

• Inconsistent alignment
• Crossing lines
• Confusing loop structure

Good Layout:

Start
  ↓
Process A
  ↓
Process B
  ↓
Decision → No → Process C
  ↓ Yes              ↓
Process D        Process E
  ↓                  ↓
Continue? ← Yes ─────┘
  ↓ No
End

Improvements:

• Clear top-to-bottom flow
• No crossing lines
• Consistent alignment
• Loop structure is clear

Next Steps

Now that you understand best practices, apply them:

1. Review Existing Flowcharts - Audit your current diagrams against these standards
2. Create a Style Guide - Document your team's specific conventions
3. Practice - Create flowcharts for various processes
4. Try Tutorials - Complete other DiagramKit.AI tutorials to reinforce learning
5. Share Knowledge - Teach colleagues these best practices

Related Documentation

• Create Your First Flowchart - Beginner tutorial
• Shape Reference - Complete guide to all 19 shapes
• Business Process Tutorial - Apply best practices to business workflows
• Software Workflow Tutorial - Technical flowchart patterns
• Template Library - Pre-built examples following best practices

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Remember: Good flowcharts are clear, consistent, and follow standards. When in doubt, simplicity and clarity win over complexity and detail. Keep practicing and you'll master professional flowcharting!