Value stream maps tell a story, but only if you can read the language. Value stream mapping symbols are the visual vocabulary that Lean Six Sigma practitioners use to document how materials and information flow through a process. Without understanding these icons, even the most detailed VSM becomes a puzzle instead of a roadmap.
At Lean Six Sigma Experts, we’ve trained thousands of professionals to build and interpret these maps through our engineering-based approach. The symbols aren’t arbitrary; each one captures specific process characteristics that help teams identify waste, bottlenecks, and improvement opportunities. Whether you’re creating your first current-state map or refining a future-state design, knowing what each icon represents is essential.
This guide breaks down 7 essential value stream mapping symbols and explains exactly what they mean. You’ll learn how to recognize process boxes, inventory triangles, information flow arrows, and more, giving you the foundation to map any operation with confidence.
1. Customer and supplier
The customer and supplier symbols mark the boundaries of your value stream. You represent both with a simple rectangular box containing the entity’s name, making them instantly recognizable as external parties. These icons anchor your entire map by showing where materials enter your process and where finished products exit to the customer.
What the symbol means
This symbol represents any external organization that either supplies materials to your process or receives the final product from it. Suppliers send raw materials, components, or information into your value stream, while customers receive your finished goods or services. The symbol itself is a basic rectangle, identical in shape for both suppliers and customers, with only the label and position distinguishing which is which.
The customer and supplier symbols define where your organization’s control begins and ends in the value stream.
You place these boxes based on their role in the material flow, not their size or importance. A supplier might be a major vendor or a small parts distributor, and a customer could be an end consumer or a distribution center. Both use the same rectangular icon regardless of scale.
Where it goes on the map
You position the supplier symbol in the upper left corner of your value stream map. Material flows from left to right across the map, so starting with suppliers on the left creates a logical reading direction. The customer symbol goes in the upper right corner, representing the endpoint where your value stream delivers value.
These boxes sit above your process boxes and remain separate from the production flow itself. You connect them to your internal processes through shipping and material flow arrows, but they stay elevated to show their external status.
What to label next to it
You write the supplier or customer name inside the rectangle. Include additional details like delivery frequency, shipment sizes, or demand patterns directly next to the box. For suppliers, you might note weekly deliveries of 500 units. For customers, you could add monthly demand forecasts or order patterns.
Common mistakes to avoid
Don’t confuse internal departments with external suppliers. Your warehouse or receiving dock is part of your value stream, not a supplier. Similarly, avoid placing multiple suppliers or customers in a single box. Each distinct external entity deserves its own separate symbol to maintain clarity in your value stream mapping symbols.
2. Process box
The process box is the fundamental building block of any value stream map. You use this rectangular symbol to represent each major step where materials undergo transformation or value is added. Understanding how to properly deploy process boxes across your map determines whether your VSM accurately reflects reality or creates confusion.
What the symbol means
This symbol captures any discrete process step where work occurs on a product or service. You draw it as a simple rectangle containing the process name or operation. The box represents activities like assembly, inspection, packaging, or machining, where materials change form or move closer to meeting customer requirements.
Process boxes show where your team actually adds value to the product flowing through your operation.
Each box represents one distinct process rather than an entire department. You might have multiple process boxes within a single work area if several different operations occur there.
Where it goes on the map
You position process boxes horizontally across the middle section of your value stream map. They flow from left to right in the sequence that materials move through your operation. Start with the first process that touches incoming materials and end with the final step before shipping to the customer.
What to label next to it
You write the process name inside the box using clear, specific language. Terms like "Weld Frame" or "Final Inspection" work better than vague labels like "Assembly." Each process box needs an accompanying data box below it that captures cycle time, changeover time, uptime, and other metrics.
Common mistakes to avoid
Don’t create process boxes for non-value-adding activities like storage or transportation. These have their own value stream mapping symbols. Avoid combining multiple distinct operations into one box just because they happen in the same area.
3. Data box
The data box sits directly beneath each process box and captures the quantitative reality of how that operation performs. You represent this with a smaller rectangle that contains the key metrics defining process efficiency. Without these data boxes, your value stream map shows only where work happens, not how well it happens.
What the symbol means
This symbol holds the measurable performance characteristics of each process step in your value stream. You fill it with metrics like cycle time, changeover time, uptime percentage, and available working time. The data box transforms your map from a simple flowchart into an analytical tool by quantifying exactly how long each operation takes and how reliably it performs.
Data boxes provide the numerical foundation for calculating lead time and identifying bottlenecks. You use these metrics to spot which processes consume the most time or create the greatest variability in your operation.
Data boxes convert your value stream mapping symbols from visual placeholders into analytical tools that reveal improvement opportunities.
Where it goes on the map
You position each data box directly under its corresponding process box. This vertical alignment creates a clear visual connection between the operation and its performance metrics. Space them consistently beneath every process symbol throughout your map.
What to label next to it
You record cycle time (C/T) as the primary metric, followed by changeover time (C/O), uptime (%), number of operators, and available time. Each metric gets its own line within the box using standard abbreviations. You might also include defect rates, batch sizes, or other process-specific measurements.
Common mistakes to avoid
Don’t leave data boxes empty because you lack current metrics. Use estimated values and mark them clearly as assumptions requiring verification. Avoid cramming excessive data into these boxes that clutters your map rather than clarifying it.
4. Inventory triangle
The inventory triangle represents stored materials waiting between processes. You draw this symbol as a simple triangle pointing upward, positioned between process boxes where materials accumulate. This icon reveals one of the most common sources of waste in any operation by highlighting exactly where products sit idle instead of flowing smoothly through your value stream.
What the symbol means
This symbol marks any location where inventory builds up between two process steps in your operation. You use triangles to show raw materials, work-in-process, or finished goods that wait in queue before the next operation. The triangle itself doesn’t specify what type of inventory it represents, only that materials are sitting still rather than moving forward.
Inventory triangles expose hidden waste by making visible the materials that accumulate when process speeds don’t match or when you produce in batches.
Where it goes on the map
You position inventory triangles between process boxes along the horizontal flow of your value stream. Place each triangle directly on the material flow line connecting two operations. The triangle sits where products physically wait, whether that’s on a pallet, in a staging area, or in a warehouse.
What to label next to it
You write the quantity of inventory stored at that location, typically measured in units, days of supply, or hours of work. Include the time materials spend waiting in that queue. Labels like "350 units / 2.5 days" clearly communicate both volume and duration.
Common mistakes to avoid
Don’t confuse inventory triangles with storage locations that are part of your facility layout but don’t represent queuing waste. Avoid placing triangles everywhere materials pause momentarily during processing. Reserve this value stream mapping symbols for significant accumulation points that impact lead time.
5. Push arrow
The push arrow shows material movement driven by production schedules rather than customer demand. You draw this as a striped or shaded arrow connecting two process boxes to indicate that the upstream process produces based on forecasts or batch requirements, pushing inventory forward regardless of downstream need. This symbol highlights one of the most common sources of overproduction waste in traditional manufacturing systems.
What the symbol means
This symbol represents any material transfer where the upstream process dictates the pace of production without a pull signal from downstream operations. You use push arrows when a process produces to a schedule or quota rather than responding to actual consumption. The striped pattern distinguishes it from smooth flow arrows by visually flagging areas where inventory tends to build because production isn’t synchronized with demand.
Push arrows reveal where your operation creates inventory faster than the next process consumes it, exposing mismatched cycle times and overproduction.
Where it goes on the map
You position push arrows between process boxes along your material flow line, specifically where one operation feeds the next without a demand signal. The arrow points from the producing process toward the consuming process, following the left-to-right flow of your value stream mapping symbols.
What to label next to it
You typically don’t add labels directly on push arrows since the striped pattern itself communicates the push nature of the flow. However, you might note batch sizes or delivery frequencies near the arrow if these details clarify the transfer pattern.
Common mistakes to avoid
Don’t use push arrows for every material transfer in traditional batch production. Reserve this symbol for highlighting specific push points you plan to convert to pull systems during future-state mapping.
6. Information flow arrow
The information flow arrow tracks communication and data movement through your value stream, separate from the physical material flow. You draw this as a thin, straight arrow that typically runs along the top of your map, connecting customers, suppliers, and internal processes. This symbol reveals how production decisions get communicated, showing whether you’re operating with real-time information or relying on forecasts and schedules.
What the symbol means
This symbol represents any electronic or manual communication that triggers or guides production activity in your value stream. You use information flow arrows to show order transmissions, production schedules, forecasts, or shipping instructions moving between entities. The arrow reveals the communication pathways that tell each process what to produce, when to produce it, and in what quantity.
Information flow arrows expose how decisions ripple through your operation, often revealing delays where outdated data drives production instead of current customer demand.
Where it goes on the map
You position information flow arrows along the top section of your map, above the process boxes and material flow. These arrows connect from the customer backward through your operation, showing how demand information travels upstream. You might also show information flowing from suppliers or between internal scheduling functions and production processes.
What to label next to it
You write the communication method and frequency next to each arrow. Labels like "Weekly forecast via email" or "Daily MRP schedule" clarify both how information moves and how often it updates. Include the specific type of data transmitted, such as order quantities, delivery dates, or production schedules.
Common mistakes to avoid
Don’t confuse information flow arrows with material flow in your value stream mapping symbols. Avoid drawing information arrows for every minor communication that occurs. Focus on mapping major data flows that directly trigger production decisions rather than routine status updates or informal conversations.
7. Kaizen burst
The kaizen burst marks improvement opportunities you’ve identified during your value stream analysis. You draw this symbol as a starburst or explosion shape positioned near any process, inventory point, or flow that needs attention. This value stream mapping symbols stands apart from all others because it doesn’t describe your current state but rather flags where future changes should happen.
What the symbol means
This symbol represents a targeted improvement project or opportunity that addresses waste, bottlenecks, or inefficiencies in your value stream. You place kaizen bursts wherever your analysis reveals problems worth solving, whether that’s excessive inventory, long changeover times, or unreliable processes. The symbol’s explosive shape visually demands attention, marking spots where your team should focus improvement efforts.
Kaizen bursts convert your value stream map from a documentation exercise into an action plan by highlighting exactly where to direct your resources.
Where it goes on the map
You position kaizen bursts directly adjacent to the element needing improvement. Place the starburst near process boxes with poor metrics, beside inventory triangles showing excessive queues, or along push arrows you plan to convert to pull systems. The burst touches or points toward the specific problem area without obscuring other symbols on your map.
What to label next to it
You write a brief description of the improvement action next to each kaizen burst. Labels like "Reduce changeover to under 10 minutes" or "Implement kanban system" communicate specific objectives rather than vague statements. Number each burst if you’re tracking multiple improvement projects simultaneously.
Common mistakes to avoid
Don’t scatter kaizen bursts across your entire map without prioritization. Focus on the most impactful opportunities first rather than marking every minor issue. Avoid using this symbol on current-state maps if you haven’t yet completed your analysis to identify real improvement needs.
Next steps
You now understand the core value stream mapping symbols that form the visual language of process improvement. These seven icons give you the foundation to read existing maps or create your own, whether you’re documenting a manufacturing line, service operation, or information flow. The real work starts when you apply these symbols to your actual processes and begin identifying the waste hiding in plain sight.
Start by mapping a single product family or value stream in your operation. Walk the process with paper and pencil, sketching each symbol as you observe material and information flow. Focus on accuracy over speed during your first attempt, verifying cycle times and inventory levels rather than guessing. Your current-state map will reveal opportunities that justify immediate improvement projects.
Building strong VSM skills requires practice and structured guidance. Lean Six Sigma Experts offers hands-on training that moves beyond theory into real-world application, helping you and your team master value stream analysis and drive measurable results in your organization.