Process Symbols |
Customer/Supplier
This icon represents the Supplier when in the upper left, the usual starting point for material flow.
The customer is represented when placed in the upper right, the usual end point for material flow.
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Dedicated Process
The dedicated process icon is a process, operation, machine or department, through which material flows.
Typically, to avoid unwieldy mapping of every single processing step, it represents one department with a
continuous, internal fixed flow path.
In the case of assembly with several connected workstations, even if some WIP inventory
accumulates between machines (or stations), the entire line would show as a single box. If there are
separate operations, where one is disconnected from the next, inventory between them and batch transfers, then
use multiple boxes.
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Shared Process
The shared process icon represents a process operation, department or workcenter that other value stream families
share. Estimate the number of operators required for the Value Stream being mapped, not the number of operators required for processing all products.
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Data Box
The data box goes under other icons that have significant information/data required for
analyzing and observing the system.
Typical information placed in a Data Box underneath FACTORY icons is the frequency of
shipping during any shift, material handling information, transfer batch size, demand quantity per period, etc.
Typical information in a Data Box underneath MANUFACTURING PROCESS icons:
C/T (Cycle Time) - time (in seconds) that elapses between one part coming off the process to the next part coming off.
C/O (Changeover Time) - time to switch from producing one product on the process to another.
Uptime- percentage time that the machine is available for processing.
EPE (a measure of production rate/s) - Acronym stands for "Every Part Every___".
Number of product variations.
Available Capacity
Scrap Rate
Transfer Batch size (based on process batch size and material transfer rate)
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Workcell
Cellular Manufacturing is an important part of VSM and Lean operations. The workcell symbol indicates that multiple processes are integrated in a manufacturing
workcell. such cells usually process a limited family of similar products or a single product. Product moves
from process step to process step in small batches or single pieces.
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Value Stream Mapping symbols are not standardized and there are many variations. Here are the
most common symbols. You may also create your own symbols for specialized applications.
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Material Symbols |
Customer/Supplier
These icons show inventory between two processes. While mapping
the current state, the amount of inventory can be approximated by a quick count, and that amount is noted
beneath the triangle. If there is more than one inventory accumulation, use an icon for each.
This icon also represents storage for raw materials and finished
goods.
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Shipments
This icon represents movement of raw materials from suppliers to the Receiving dock/s
of the factory. Or, the movement of finished goods from the Shipping dock/s of the factory to the customers.
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Push Arrow
This icon represents the "pushing" of material from one process to the next process.
Push means that a process produces something regardless of the immediate needs of the downstream process.
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Supermarket
This is an inventory 'supermarket" (kanban stockpoint). Like a
supermarket, a small inventory is available and one or more downstream customers come to the supermarket to
pick out what they need. The upstream workcenter then replenishes stocks as required.
When continuous flow is impractical, and the upstream process
must operate in batch mode, a supermarket reduces overproduction and limits total inventory.
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Material Pull
Supermarkets connect to downstream processes with this "Pull" icon that
indicates physical removal.
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FIFO Lane
First-In-First-Out inventory. Use this icon when processes
are connected with a FIFO system that limits input. An accumulating roller
conveyor is an example. Record the maximum possible inventory.
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Safety Stock
This icon represents an inventory "hedge" (or safety stock)
against problems such as downtime, to protect the system against sudden
fluctuations in customer orders or system failures. Notice that the icon is
closed on all sides. It is intended as a temporary, not a permanent storage of
stock; thus; there should be a clearly-stated management policy on when such
inventory should be used.
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External Shipment
Shipments from suppliers or to customers using external
transport.
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Information Symbols |
Production Control
This box represents a central production scheduling or control department, person or
operation.
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Manual Information
A straight, thin arrow shows general flow of information from memos, reports, or
conversation. Frequency and other notes may be relevant.
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Electronic Info
This wiggle arrow represents electronic flow such as electronic data interchange (EDI),
the Internet, Intranets, LANs (local area network), WANs (wide area network). You may indicate the frequency
of information/data interchange, the type of media used ex. fax, phone, etc. and the type of data exchanged.
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Production Kanban
This icon triggers production of a pre-defined number of parts. It signals a supplying
process to provide parts to a downstream process.
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Withdrawal Kanban
This icon represents a card or device that instructs a material handler to transfer
parts from a supermarket to the receiving process. The material handler (or operator) goes to the
supermarket and withdraws the necessary items.
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Signal Kanban
This icon is used whenever the on-hand inventory levels in the supermarket between two
processes drops to a trigger or minimum point. When a Triangle Kanban arrives at a supplying process, it
signals a changeover and production of a predetermined batch size of the part noted on the Kanban. It is
also referred as "one-per-batch" kanban.
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Kanban Post
A location where kanban signals reside for pickup. Often used with two-card systems to
exchange withdrawal and production kanban.
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Sequenced Pull
This icon represents a pull system that gives instruction to subassembly processes to
produce a predetermined type and quantity of product, typically one unit, without using a supermarket.
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Load Leveling
This icon is a tool to batch kanbans in order to level the production volume and mix
over a period of time
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MRP/ERP
Scheduling using MRP/ERP or other centralized systems.
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Go See
Gathering of information through visual means.
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Verbal Information
This icon represents verbal or personal information flow.
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General Symbols |
Kaizen Burst
These icons are used to highlight improvement needs and plan kaizen workshops at
specific processes that are critical to achieving the Future State Map of the value stream.
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Operator
This icon represents an operator. It shows the number of operators required to process
the VSM family at a particular workstation.
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Other Stuff
Other useful or potentially useful information.
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Timeline
The timeline shows value added times (Cycle Times) and non-value added (wait) times.
Use this to calculate Lead Time and Total Cycle Time.
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Extended VSM Symbols |
Rail Shipment
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Air Freight
Delivery of material by air freight.
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Expedited
This symbol shows deliveries of product or information that are always or usually expedited.
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Milk Run
A "Milk Run" vehicle makes multiple stops to pick up or deliver items at multiple locations. Milk runs often, but not necessarily,
follow a fixed route. The advantage of a milk run is that it does not require a full load for each delivery to be economical.
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Warehouse
The Warehouse icon can represent an internal or external warehouse. It
may also be used in lieu of the Customer/Supplier icon.
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Cross-Dock
In Cross-Docking inbound and outbound trucks are closely coordinated
so that materials move directly from inbound trucks to outbound or, at least, with only a brief staging.
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Orders
This icon represents conventional sales orders or purchase
orders.
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Phone
The telephone represents some type of telephone communication and is
often used for telephone orders.
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Batched Kanban
Kanban cards or signals sent or received in batches.
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Control Center
Control Center icon for centralized kanban control
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