420 likes | 628 Vues
Chapter 8. Setup Reduction. SMED – History of Setup Reduction. Developed by the Japanese Shigeo Shingo Father of SMED and Poka Yoke Shingo prize named in his honor Incorporated into the Toyota Production System. Setup Definitions. Setup time
E N D
Chapter 8 Setup Reduction
SMED – History of Setup Reduction • Developed by the Japanese • Shigeo Shingo • Father of SMED and Poka Yoke • Shingo prize named in his honor • Incorporated into the Toyota Production System
Setup Definitions • Setup time • The time required for a specific machine, resource, work center, process, or line to convert from the production of the last good piece of item A to the first good piece of item B. – APICS Dictionary, 11th edition • Internal setup • The part of the setup which must be done while the process is stopped. • External setup • The part of the setup which can be done while the process is still running.
SMED – The Steps • Select high-impact initial implementation targets • Establish a baseline • Document and study four elements: • Internal and external waste • Replacement and adjustment waste • Move internal elements to external • Overall waste elimination • Commit to continuous improvement cycles
Single Minute Exchange of Dies • The SMED approach • Observe (video tape) a changeover • Define internal and external elements • Separate external elements to a time when equipment is running • Shift as many internal elements to external as possible • Streamline the internal elements • Streamline the external elements
Setup Reduction Goal • To drastically reduce the time it takes, from when a customer places an order, to when it is delivered to the customer’s receiving dock. • Makes it feasible for a company to fully utilize its assets by producing varying products using the same manufacturing equipment. • Reduces inventory by supporting building products to order.
Goals of the Setup Initiative • Eliminate all setup waste categories associated with the setup* process • Reduce setups to a one-step process • Reduce setup time to “0” Part “A” Running Setup* Part “B” Running *Goal 1 and 2 support 3 – the one real goal!
Setup Waste Categories • External • The part of the setup which can be done while the process is still running. • Activities such as searching, locating, or moving needed items to and from the work area • This could be 50% or more of the setup time • Internal • The part of the setup which is done while the process is stopped. • Activities done at the work area such as loading and unloading fixtures • Replacement waste • Activities that cause you to disassemble and reassemble the setup using some of the same parts • Adjustment waste • The activity and process of making a “setup piece”
How does setup reduction fit in with the strategic vision? Flow/Pull: Enables the reduction of lot sizes - a key element to increasing flow. Six Sigma Quality: Changes adjustments into settings. Reduces variation of setups which lead to variation in product and service. Waste Elimination: We have not found a buyer for setup time, so it must be waste. Setup Reduction
Reduced setup times allow: You to be cost competitive Carry smaller lot sizes without increasing part cost Smaller lot sizes result in: Reduce WIP (inventory) Reduced time from raw material to finished goods (manufacturing lead time) Reduced manufacturing lead-times result in: Faster response to customer requested changes Producibility problems being identified quicker Reduced scrap and rework costs Increased manufacturing flexibility, capability and capacity Why Setup Reduction? See Figure 8.0 page 312
Inventory Reduction • Storage space must be reserved for the maximum inventory conditions. • Switching from a one-month lot size to a one-day lot size reduces the required inventory space by 97%. Rule #1: Do not attempt to go to one-day customer requirements lot production on any machine unless your TPM initiative is in place and equipment uptime is assured.
Does Quality Improve? Why? • Quality problems and defects related to the setup process are reduced because: • Setups are eliminated or has reduced actions, every action can lead to a problem • Trial runs of the new part are eliminated • If defective parts are not produced, defective parts cannot be shipped • Quality problems show up quickly • Smaller lot sizes, shorter assembly time
Typical Results from Setup Reduction • First Stage • 50% improvement from original setup • Moved elements from internal to external • Majority of benefits come from 5S • Second Stage • 75% improvement from original setup • Perform process improvement on remaining internal elements • Elimination of non-value added steps • Third Stage • 90% improvement from original setup • Streamline remaining internal and external elements
Summary • Setup reduction is a powerful tool which improves a plant’s ability to provide customer satisfaction while better utilizing its assets • Readily adopted by a plant’s manufacturing team • because it is easily implemented, • has relatively low cost, • and provides quick relief to the tedious drudgery of long setups
Basic Steps in a Changeover • Preparation; check materials, get instructions, etc. • Removing tools, mounting tools, etc • Measurements, settings, and calibration. • Trial runs and adjustments. See Figure 8.2 page 318
Minutes 60 Position/ adjust Prepare 45 tools and fixtures 30 Position/ adjust Search Prepare 15 tools and fixtures Position/ adjust 3 4 1 2 SMED A Typical Setup Internal time
In which setup is improvement a priority? Collect appropriate data Standard and actual setup durations Takt time Establish priorities to work on TAKT 3 5 4 3 2 4 2 1 5 1 setup time = machine time = Choose Where to Begin
High Impact Targeted Processes Select an area that will have a significant impact on the organization • Bottlenecks • High rework occurrences due to poor setup procedures • Learning curve each time process is performed • Low reliability of results • Customer complaints about company response time to a requested change in services
Step 1: Team and Equipment Selection • Choose a setup reduction champion • Provide training to the champion • Choose a setup reduction team • Setup person • Machine operator • Facilities representative • Manufacturing engineer • Area leader • Setup reduction champion to train the setup reduction team • Begin the effort
Step 2: Establish a Baseline Baselines are best established using video of the existing process: Why • Visually depicts the process • Permits multiple viewings to study the process • Retains objectivity • Gate-to-gate view ideal How • Narrate and document the steps • Utilize real-time equipment if available • Include audio as part of the video Document results in a worksheet Rule #3: No guess work – video tape all setups that you want to improve. Use the time and date function on the camera.
Step 3: Document the Setup • Review the videotape • List all activities that occurred • Identify tasks and time to perform each task • Use setup analysis form • Distinguish between internal and external steps and waste • Identify improvement opportunities
Team: __________ Date:______ SETUP ANALYSIS FORM Proposed time Current time Improvement No. Task/Operation Internal External Internal External Current total Improve total Internal: Operations that can be performed only when the machine is stopped. External: Operations that can be performed while the machine is in operation. Key Terms: Assemble, Dismantle, Use, Transportation (Empty), Transportation (Full), Take, Add, Change, Put Down, Find, Choose, Inspect, Reposition, Hold, Wait, Look For, Run, Prepare Setup Analysis Form
12/08 Team: _______________ V-5 Ballhead Cell Date: __________ setup ANALYSIS FORM Current time Proposed time Improvement No. Taask/Operation InternalExternal Internal External 1 Permanent program for edits & offsets 3:00 0 Add edits & offsets Develop tool life maintenance program 2 2:05 Change tool 0 Indexer permanently assembled 0 3 12:38 Assemble indexer Relocate indicator closer to machine 4 :05 :30 Looking for indicator .... :45 Speeds and feeds improvements Run machine 45 1:20 Locate high usage tools closer to machine 46 3:34 0 Looking for tools Preparing gages Prepare gages ahead of time 0 47 2:38 Purchase new deburring knife 48 :42 2:20 Deburr part Inspect 1st piece 49 5:39 Inspect per fixture (continue machine cycle) 19:12 Current total Improved total 18:28 36:17 134:20 10:09 Internal: Operations that can be performed only when the machine is stopped. External: Operations that can be performed while the machine is in operation. Key terms: Assemble, Dismantle, Use, Transportation (Empty),Transportation (Full), Take, Add, Change, Put Down, Find, Choose, Inspect, Reposition, Hold, Wait, Look For, Run, Prepare MazakV-5 Setup Reduction
Step 4: Shift the elements • Reduce internal • Increase external Convert internal setup to external setup Rule #4: The greatest reduction in setup time occur from the elements that take the longest time. Concentrate on the longest time elements first.
Pre-setup activities Tools cleaned and sharpened Gages preset & supplies ready Materials transported/ sequenced Tools/fixtures/supplies positioned Getting paperwork Post setup activities Clean, inspect, return, and repair tools, materials and fixtures Store all items in assigned locations General 5S activities Area sorted and cleaned Use shadow boards All necessary tools nearby Paperwork & standards posted in area Next lot/part (incoming) near area Incoming and outgoing areas are clearly identified Visual flow of work through area Use dedicated tool or die carts for each area/machine How to Move Internal to External
Rule #2 • 5S workplace organization must be in place to receive the fifty percent or more reduction in setup times which can occur from just being ready. • Make sure travel distances are minimized. • Number of movements are reduced. • Tools, tool carts, jigs, fixtures, gauges, and instructions are nearby and ready.
Converting Internal toExternal Setup • Re-examine operations to see if any steps were mistakenly assumed to be internal • Analyze ways to convert internal steps to external • Move required materials and tools to the workstation prior to the start of changeover • Remove previous tools and materials after the changeover is completed; or, use separate material handlers for the task
Don’t wait for perfect conditions… JUST DO IT! Eliminate all unnecessary steps Convert as many internal steps to external steps as possible Improve/reduce the internal steps time Improve/reduce the external steps time Step 5: Waste Elimination
Improvement Opportunities • Specially designed cart to organize tooling • Quick release fasteners • Stoppers to quickly position parts • Locating pins and holes to eliminate adjustments • Standardized die heights • Conduct activities in parallel – teamwork • Minimize the number of tools and parts Rule #5: Do not confuse motion and movement with work.
Improvement Opportunities • Stage all tools and materials • Store high use items at the point of use • Proper storage and labeling of all items • Use tool boards • Organize tools and parts in order of usage • Sharpen and pre-set tools • Pre-heat, pre-adjust, pre-etc….
Standardize Functions Where possible, standardize: • Sizes and dimensions of all machine parts and tools • Functional elements of tooling, fixtures, molds/dies, etc. Standardization requires uniformity necessary for setup operations • Clamping • Centering • Dimensioning • Expediting • Grasping
Preceding kit Kits location kit 1 Machine kit 2 kit 3 kit 4 kit 5 Next kit Improvement Opportunity • Kitting of tools, gauges, accessories, information
BEFORE AFTER machine machine Decrease walking time & searching Improvement Opportunity: • Bring equipment together
Improvement Opportunity • Prepare tools ahead of time • Pallet changers • Load/unload while machine is running • Tear down/set up while machine is running
Promote Clamps andOne-touch Fasteners • Use “one-touch” functional methods such as wedges, cams, clamps, or springs • Use interlocking methods that simply fit and join two parts together • Analyze the direction and magnitude of the force required in clamping methods
Adopt Parallel Operations • Two people performing operations simultaneously reduce waste of movement • Increases operating rate of the machine • Parallel operations can reduce setup times by more than 50%
Eliminate Adjustments Settings vs. Adjustments • Settings occur when the position of an item is changed • Adjustments occurs when the item is tested and repeatedly adjusted to a new position Adjustment can be eliminated if a gage is used to precisely determine the correct position of the limit switch • Use dial gauge or numerical control device for greater precision • Use calibration markings on the machine • Have fixed locations
Mechanization • Most costly technique for reducing changeover times • Use only after all other techniques have been implemented
Step 6: Continuous Improvement • Sustain the improvements • Leverage successes across other areas and machines • Update standards as appropriate • Document standard practices (setup sheets; WI’s; digital pictures) • Create work order lot size calculator to determine lot size quantities Rule #6: Develop a rewards and recognition program for the setup reduction effort. Display the results of how each team is doing. Have celebrations as milestones are reached.
Commit to Continuous Improvement • Similar to Kaizen, never quit reducing changeover times • Select different team members to find fresh ideas • Expand the scope of team members to include: • Equipment manufacturers • Software developers • Suppliers of information or materials Rule #7: It is time to start inviting your suppliers to attend the next training class. You cannot become world class without world class suppliers.
Summary • Majority of initial setup reduction activities yield 25% to 75% reduction in internal changeover time with no capital invested • Follow a step-by-step process • Utilize teams • Commit to continuous improvement