Value stream map symbols
A value stream map is drawn from a small, fixed vocabulary, and that is most of why it travels: two people from different companies can read each other’s maps. What follows is each mark, what it asserts, and — where there is one — the symbol it is most often confused with and what confusing them costs.
The names below are read from this product’s own interface at build time, so a symbol is called here what it is called in the editor. The drawings follow the conventions set out in the literature and used by the tool.
Parties and processes
The boxes. A value stream map is bounded by a customer and a supplier, and everything between them is either a process on the flow or the office that schedules it.
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Customer
The top-right corner of the map, always. Carries the demand quantity and the shipment frequency — the two figures takt time is computed from, which makes this box the origin of every comparison the map goes on to make.
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Supplier
The same plant outline in the top-left corner. Drawn identically to the customer on purpose: the shape says *outside the boundary you are mapping*, and which corner it is in says which side of the flow it is on.
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Process
One box per flow step — a place material stops and something is done to it. Two machines a part moves between without stopping are one box, not two, and this is the judgement that decides whether a map has eight boxes or forty.
Often confused with: Not one box per machine, and not one per department. A map drawn per machine stops being about flow and becomes an equipment list with arrows.
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Data box
Sits under each process box and holds what was measured there: cycle time, changeover, uptime, operators, shift pattern, batch size, scrap. This is where the map stops being a diagram — every figure the analysis produces is computed from these boxes.
Often confused with: The commonest error is filling it from the routing file. A data box records what was observed on the floor; if the standard matched the observation there would be nothing to map.
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Production control
The office that decides what gets made and when — MRP, ERP, a planner, a whiteboard. It sits at the top of the map because every information arrow starts here, and the shape of those arrows is usually the explanation for where the inventory is.
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External process
An operation performed outside the boundary you are mapping — plating, heat treat, an outside machining vendor. Drawn as a process because material really does go through it, and marked as external because you cannot walk it and time it.
Often confused with: It carries a turnaround time in working days rather than a cycle time in seconds, and folding that into processing time instead of waiting time is a common way to make lead time look better than it is.
Inventory and buffers
Where material waits. These four marks look similar and commit you to different things — the difference between them is the difference between a push system and a pull one, and it is the single most consequential distinction on the map.
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Inventory
A triangle with a count in it, placed between two processes. Raw material, work in process and finished goods are all this shape; what distinguishes them is where on the map they sit. The count divided by daily demand becomes days of waiting, and those days are almost always where the lead time actually is.
Often confused with: Count it on the floor. The number in the inventory system and the number on the floor differ routinely, and the map is a record of the floor.
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Supermarket
Three shelves, closed on the right and open on the left: a controlled store that the downstream process withdraws from and the upstream process replenishes. Open on the supplying side because that is the side the material comes back in from. Its size is calculated, not chosen.
Often confused with: This is the distinction that matters most on the map. A supermarket is replenished by consumption; a triangle is whatever the schedule pushed. Drawing a supermarket where an ordinary buffer sits claims a pull system that does not exist, and every future-state argument built on it is then arguing about a plant nobody is running.
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FIFO lane
A channel rather than a pile, with the sequence running through it. The whole claim of a FIFO lane is that what goes in first comes out first — which a heap of inventory does not promise — and it carries a hard maximum: when the lane is full the upstream process stops.
Often confused with: The capacity is not decoration. A FIFO lane without an enforced ceiling is a buffer with a tidier name, and the stopping rule is the thing that makes it couple two processes together.
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Safety stock
The same triangle, hatched. Rother & Shook do not give safety stock a different shape — they write on the same one — so the hatching is a legibility choice rather than a different symbol: it survives a greyscale print and a projector, where a fill colour and a small caption do not.
Often confused with: Safety stock absorbs variation and is sized for it. Calling ordinary excess inventory “safety stock” is the most common way a map launders a problem into a policy.
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In transit
Material moving between sites, and the truck mark that carries the shipment frequency with it. Drawn on the arrows into and out of the map, where it is the reason the boundary has the lead time it does.
Often confused with: A weekly delivery is not a week of transport time. The frequency and the transit time are different figures, and confusing them shifts days from one side of the timeline to the other.
Material flow and control
How movement is authorised. The arrow style is not decoration — it states whether a station produced because it could or because the next one took something, and the arithmetic downstream depends on the answer.
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Push
The striped arrow: material produced to a schedule and moved on regardless of whether the next process needed it. Most arrows on most current-state maps are this one, and each of them explains a triangle sitting just downstream of it.
Often confused with: Push is not a criticism, it is a description. Marking everything as pull because the plant has kanban cards somewhere produces a map that cannot explain its own inventory.
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Pull / Kanban
Physical withdrawal: the downstream process takes what it needs from a store, and that act is what authorises the upstream process to make more. The mark belongs with a supermarket — a pull arrow with an ordinary triangle behind it is a contradiction.
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Sequenced pull
The downstream process sets the sequence and the upstream one builds to it, with no store held between them. Used where holding a supermarket is impractical — too many variants, or parts too large to keep on hand.
Often confused with: It is a pull system without inventory, not a push system with a schedule. The distinction is that the sequence comes from actual downstream consumption rather than from a forecast.
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Go-see
A person walks to the downstream process, looks at what is there, and decides what to make. Honest to draw and worth drawing: it is scheduling that depends on somebody being available and paying attention, which is a fragility a schedule box hides.
Information flow
The half of the map that explains the other half. A pile of inventory is rarely a storage decision; it is usually a scheduling one, and these are the marks that show it.
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Manual
A straight thin arrow: a schedule, a list, a phone call, somebody walking a printout to a station. Manual signals carry their own delay, and that delay is real time even though nothing physical moved.
Often confused with: This is where the map starts asking questions. A weekly manual signal into a process that changes over daily is a mismatch the drawing makes visible and the schedule never did.
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Electronic
The lightning bolt: an electronic signal — EDI, an MRP release, an automatic replenishment message. Drawn differently from a manual one because the two fail differently, and the map is partly a record of how information can go wrong.
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Withdrawal kanban
Authorises the consumer to take from a store. This is the default reading of a pull link and the one a continuous replenishment loop runs on.
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Production kanban
Instructs the supplying process to make what was taken: same quantity, opposite direction. The withdrawal and production pair together is what makes a supermarket self-regulating rather than a store somebody tops up when they remember.
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Signal kanban
The triangle card. Nothing is produced until the store falls to a trigger point, and then a whole batch is. It exists because a process with a long changeover cannot replenish one container at a time — so the loop stops being continuous and becomes a reorder point.
Often confused with: It is the one kanban with a trigger point to compute. Treating it as an ordinary pull loop hides the batch, and the batch is the reason the changeover matters.
On the map itself
Three marks that are not flow: who does the work, where the improvement goes, and the line along the bottom that turns the drawing into an analysis.
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Operator
Drawn inside the process box, one per person. A practitioner reads headcount off a map by counting shapes before reading a single figure, which is why it is a mark rather than a row in the data box.
Often confused with: The count is of people at the station, not of the operator requirement the analysis computes. The gap between the two is a finding.
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Kaizen burst
The starburst marking where an improvement has to happen for the future state to work. It belongs on the future-state map, attached to the specific process or connection it changes.
Often confused with: A burst is a commitment, not a wish. One with no owner and no date is how a future-state map becomes a wall decoration.
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Timeline
The sawtooth along the bottom: waiting time on the upper step, work time on the lower, summed separately. The lower sum is processing time, both together are production lead time, and the ratio is process cycle efficiency. This line is what makes the drawing an analysis.
Often confused with: Mixing units. Cycle times are seconds and waiting is days; adding them without converting produces a lead time wrong by orders of magnitude that looks entirely plausible on a slide.
The vocabulary is only half of it — the figures the marks produce are defined in the glossary, and the sequence they are collected in is set out in how to create a value stream map.