VSM 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.
|Dedicated Process||This 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 and batch transfers, then use multiple boxes.
|Shared Process||This is 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.|
|Data Box||This icon 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 operators – use OPERATOR icon inside process boxes · Number of product variations · Available Capacity · Scrap rate · Transfer batch size (based on process batch size and material transfer rate)
|Workcell||This 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.|
VSM Material Symbols
|Inventory||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.
|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|
|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.|
|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.
|Material Pull||Supermarkets connect to downstream processes with this “Pull” icon that indicates physical removal.|
|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.|
|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.|
|External Shipment||Shipments from suppliers or to customers using external transport.|
VSM Information Symbols
|Production Control||This box represents a central production scheduling or control department, person or operation.|
|Manual Info||A straight, thin arrow shows general flow of information from memos, reports, or conversation. Frequency and other notes may be relevant.|
|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.|
|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.|
|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.|
|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.|
|Kanban Post||A location where kanban signals reside for pickup. Often used with two-card systems to exchange withdrawal and production kanban.|
|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.|
|Load Leveling||This icon is a tool to batch kanbans in order to level the production volume and mix over a period of time|
|MRP/ERP||Scheduling using MRP/ERP or other centralized systems.|
|Go See||Gathering of information through visual means.|
|Verbal Information||This icon represents verbal or personal information flow.|
VSM 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.|
|Operator||This icon represents an operator. It shows the number of operators required to process the VSM family at a particular workstation.|
|Other||Other useful or potentially useful information.|
|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.|