Process Flow Charting 241

cell

An arrangement of machines, tooling, materials, and operators structured around the design of similar products. Cells encourage smooth product flows and use space efficiently.

changeover time

The time it takes to tear down the setup for the current product type, prepare for the next product type, and successfully produce the first good part. Manufacturers try to reduce changeover time as much as possible.

current-state flow chart

A visual tool that documents the present condition of a manufacturing environment, including any flaws or errors. Current-state charts are sometimes called present-state charts.

cycle time

The time it takes to perform a task and forward it to the next step. One of the major goals of lean is to match cycle time to takt time.

future-state flow chart

A visual tool that shows how the process can look after improvements have been implemented. A future-state chart shows the process with flaws and errors eliminated.

information symbols

A type of value stream mapping symbol that indicates the form, flow, and direction of communication and data. A jagged arrow, which represents electronic information, is an example of an information symbol.

kanban

A Japanese word meaning "card signal." In pull systems, kanban represents any visual method used to show the need for parts or products to be moved or produced.

lead time

The time spent between the original customer order for a particular product and its final delivery to the customer. Manufacturers try to reduce lead time to improve customer satisfaction.

material symbols

A type of value stream mapping symbol that indicates the origin, location, and movement of raw materials and parts within the system. A triangle, which represents inventory, is an example of a material symbol.

metrics

Data used to gauge performance. Metrics can be used to detect errors and track an operation's progress.

non-value added

Activities that do not contribute to the product or the process and should therefore be eliminated. Non-value added steps are waste.

non-value added

Activities that do not contribute to the product or the-process and should therefore be eliminated. Non-value added steps are waste.

non-value added but essential

Activities that support value added steps but that do not directly contribute to the product. Material handling is often considered a non-value added but essential activity.

present-state flow chart

A visual tool that documents the current condition of a manufacturing environment, including any flaws or errors. Present-state charts are sometimes called current-state charts.

process flow charts

A visual representation of the steps required to manufacture a product. Spaghetti diagrams, process maps, and value stream maps are examples of process flow charts.

process map

A process flow chart that uses symbols and arrows to show the flow of the manufacturing process. Process maps are more complex than spaghetti diagrams.

process symbols

A type of value stream mapping symbol that indicates actions that take place or the locations where processes occur. A U-shaped symbol, which represents a cell, is an example of a process symbol.

product family

Groups of products that use similar machines or processes during manufacture. Grouping products according to family simplifies process flow charting.

pull system

A material management system in which parts are not delivered to machines until they are needed. Pull systems are based on actual demand for products.

push system

A production method based on keeping up with preset inventory levels or with due dates for customer orders. Push systems often lead to excess inventory and waste.

spaghetti diagram

A process flow chart that uses a continuous line to trace the path of a product through the manufacturing process. Spaghetti diagrams expose inefficient layouts and large distances traveled between steps.

value

A real or perceived quality that satisfies the needs and wants of a customer. Value includes the features of a product, as well as other qualities associated with the product.

value added

Any part of the production process that improves the product for the customer. For a process to be value-added, a customer must be willing to pay for it.

value stream map

VSM. A sophisticated process flow chart that uses symbols, metrics, and arrows to depict the manufacturing process and track performance. Value stream maps help determine which steps add value and which do not.

waste

Any thing or process that does not add value to a product. Scrap and waiting are common forms of waste.