Visual Factory Three reasons for using visual management tools: To make problems visible To help workers and management stay in direct contact with gemba (the workplace) To clarify targets for improvement Production boards and schedule boards are examples of a visual factory. Before the start of a shift, the department supervisor uses the boards for a short discussion on planned activities for the day and any specific problems. Lean Tools

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Visual Factory (Continued) Andon: A visual control device in a production area. Typically a lighted overhead display, giving the current status of the production system. Jidohka is defined as a device that stops a machine whenever a defective product is produced. It is autonomation, that is, a form of automation with human elements attached. When an equipment malfunction occurs, a light turns red or a signal comes on to indicate a problem. The operator or maintenance personnel must respond to find the source of the problem and to resolve it. The kanban system provides material control for the factory floor. The cards control the flow of production and inventory. The visual factory places an emphasis on setting and displaying targets for improvement. The concept is that various operations have a target or goal to achieve. The standard time is initially set higher than the target. However, as the operation is performed, the operator tries to beat the old time, until the goal is met. In summary, the visual factory enables management and employees to see the status of the factory floor at a glance. The current conditions and progress are evident and any problems can be seen by everyone. Lean Tools

Muda, The Seven Wastes Muda are non-valued added activities in the workplace. The elimination of muda is essential for providing a cost-effective and quality product. There are 7 types of muda or waste: Overproduction: Producing more than is required. Inventory: Extra inventory does not add value to the product. Repairs/rejects: It is expensive to have repair work or rejects. Motion: The physical activities must be analyzed to reduce lost motion. Processing: This refers to modifying a work piece or piece of information. Waiting: When the operator is idle due to machine imbalances, lack of parts, or machine downtime. Transport: Any and all transport of the product is waste. Moving the product adds no value. Lean Tools

Kanban T. Ohno was the originator of the Kanban method. Kanban is a method of material flow control in the factory. It is intended to provide product to the customer with the shortest possible lead times. Inventory and lead times are reduced through Heijunka (leveling of production). The order to produce parts at any one station is dependent on receiving an instruction, the kanban card. Only upon receiving a kanban card will an operator produce more goods. This system aims at simplifying paperwork, minimizing WIP and finished goods inventories. Due to the critical timing and sequencing of a kanban system, improvements are continually made. A kanban system can not have production halted by machine failures or quality problems. Every effort is made to eliminate causes of machine downtime, to eliminate sources of errors in production, promoting production efficiency and improving quality. Kanban systems are applicable in repetitive production plants, but not in one-of-a-kind production operations. Lean Tools

Kanban (Continued) If a Kanban system is used, with cards indicating the need to resupply, the method of feeding an assembly line could be achieved using the following process: Parts are used on the assembly line and a withdrawal kanban is placed in a designated area. A worker takes the withdrawal kanban to the previous operation to get additional parts. The WIP kanban is removed from the parts pallet and put in a specified spot. The original withdrawal kanban goes back to the assembly line. The WIP kanban card is a work instruction to the WIP operator to produce more parts. This may require a kanban card to pull material from an even earlier operation. The next operation will see that it has a kanban card and will have permission to produce more parts. This sequence can continue further upstream. Lean Tools

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KANBAN/PULL APPROACHES Take item only when needed Used in multi-stage production Initially does not look that good Wide variety of implementations possible Lean Tools

KANBAN/PULL Location is running short of material Notify previous location Material only flows when needed Not when you think it will be needed Work is pulled through facility Example - HP Lean Tools

KANBAN/PULL NOTIFICATION Cards easily damaged, easily lost, cheap Computer Signal Can cover large distances, more complex Kanban Squares marks painted on floor, simple, cheap, less easily damaged Slots for items place on shelves, simple, cheap Lean Tools

KANBAN/PULL Simple Cheap Gives good control No look ahead Can reduce inventories Reduces lead times Usually manual Lean Tools

Poka-Yoke Shingo lists characteristics of poka-yoke devices: 100 percent inspection is possible Devices avoid sampling for monitoring and control Poka-yoke devices are inexpensive Mistake-proofing can be accomplished through a control method by preventing human errors or by using a warning mechanism to indicate an error. Some of the control methods to prevent human errors include: Designing a part so it can not be exchanged by mistake Using tools and fixtures that will not load a mis-positioned part Having a work procedure controlled by an electric relay A signaling mechanism warns about possible sources of error. Root cause analysis and corrective action is required before work resumes. Lean Tools

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Single Minute Exchange of Die (SMED) Single Minute Exchange of Die (SMED) concept is to take a long setup change of perhaps 4 hours in length and reduce it to 3 minutes. Shigeo Shingo, developer of the SMED system has used it quite effectively in the Toyota Production System for just-in-time production. Single minute exchange of die does not literally require die changes to be performed in only one minute, it merely implies that die changes are to be accomplished under a single digit of time (nine minutes or less). SMED is a system that reduces the dependence on the long term experience of operators to perform an effective changeover. SMED will have a system to reduce the skill level needed for setup changes. Quick changeover methods do away with the economic order quantity (EOQ) method. The EOQ tries to balance the cost of inventory to the cost of setup. The result is that excess inventory will be carried by the firm. The value of long production runs through EOQ theory is no longer valid. SMED will enable a factory using lean manufacturing to produce to what is ordered by the customer. Lean Tools

SMED (Continued) Setup Improvement Steps The beginning of a SMED project is to recognize that setups can be improved by distinguishing between internal and external setup conditions. Identify what can be performed before shutting down the machine (external setup times), and identify what has to be done when the machine is shut down (internal setup time). In planning a SMED project, the actual conditions and steps of the die changeover must be detailed. Every step in the setup process from start to finish is broken down and classified. External setup operations should include: Preparation of parts Maintenance Finding parts Cleaning of spares, etc. Measuring parts A second look must be made to re-examine the existing internal setup elements and to convert more of those elements into external setup. Lean Tools

SMED (Continued) Setup Improvement Steps (Continued) The setup team will need to generate some creative options to what is currently being done. Brainstorming sessions and problem solving sessions are needed to continuously improve the setup process. All elements of internal and external setup must be reviewed in detail and streamlined in order to move to the 1 digit goal. Perhaps the goal is unattainable, but efforts are made to go as low as possible. Once a SMED procedure is agreed upon, the setup team should practice the process and critique itself for improvements. Based on specific applications, the reduction of cycle time can have a considerable impact on the containment of costs and improvement in productivity. Lean Tools

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Lean Glossary Andon Board - A visual control device in a production area. Typically a lighted overhead display, giving the current status of the production system. Continuous Flow Manufacturing (CFM) - Material moves one-piece at a time, at a rate determined by the needs of the customer, in a smooth and uninterrupted sequence, and without WIP. Just-in-Time (JIT) - A system for producing and delivering the right items at the right time in the right amounts. Level Loading - The smoothing or balancing of the work load in all steps of a process. Muda - A Japanese term meaning any activity that consumes resources but creates no value. Poka-Yoke - A mistake-proofing device or procedure to prevent or detect an error which adversely affects the product and results in the waste of correction. Pull - A system of cascading production and delivery instructions from downstream to upstream activities. Lean Tools

Lean Glossary (Continued) Single Minute Exchange of Dies (SMED) – Rapid changeovers of production machinery, the objective is zero setup time. Single-Piece-Flow - A situation in which one complete product proceeds through various operations like design, order-taking, and production, without interruptions, back flows, or scrap. Standard Work - A precise description of each work activity, specifying cycle time, takt time, the work sequence of specific tasks, and the minimum inventory needed. Takt Time - The available production time divided by the rate of customer demand. Value Stream - The specific activities required to design, and provide a specific product. Visual Control - The placement in plain view of all the tools, parts, production activities, and indicators of production system performance, such that the status of the system can be understood easily and quickly. Lean Tools