Production Management I

Transcription

1 Production Management I - Lecture 9 - Version 13 Contact: Dipl.-Ing. P. Burggräf [email protected] WZL 414 Tel.: L09 Page 0

2 Content Lecture 9 1. Directory L9 page II 2. Summary L9 page III 3. Glossary L9 page IV 4. Lecture Highlights L9 page 1 The way to Lean Production L9 page 2 Lean Thinking: Orientation of value from customers view L9 page 4 A typical factory L9 page 5 Lean Production begins at the customer L9 page 6 Role model Toyota Production System L9 page 8 Production smoothing as a base for stable processes L9 page 9 Process synchronization as a base of capacity L9 page 10 Kanban for autonomous material control acc. to the pull principle L9 page 11 Empowerment and teamwork L9 page 12 Lean Automation Autonomation L9 page 13 Poka Yoke for failsafe working L9 page 14 The 7 types of wasting in the Lean Production L9 page 15 Visual management as a control and leading instrument L9 page 16 Value Stream design: The current tool in Lean Production L9 page 18 Prozess optimisation with the value stream principle L9 page 19 6S Order & Cleanlineless L9 page 20 Optimized sidewalks & utilization of capacity in U-Layout L9 page 21 Optimization of setup work L9 page 22 KVP workshops in the production L9 page 23 continuous improvement (Kaizen) L9 page 24 Lean Production: a challenge for the culture in the enterprise L9 page 25 Production Systems in different enterprises L9 page 26 List of literature L9 page 27 L09 Page 1

3 Summary Based on cost pressure and restrictions, different management concepts have been discussed and implemented in producing enterprises. In particular the automobile industry takes in pioneer role discussion about integrated order systems for the different functions. In the area of production, producing enterprises use production systems to harmonize their activities in production and to integrate their activities in a comprehensive concept. Production systems describe the constitutional structure of the whole production organization and contain the representation off all concepts, methods and tools, which constitute the effectiveness and efficiency of the production flow. They consort and standardize the sequences of functional units in the production and form the platform for the continuous advancement and optimization at the same time. Production systems are normally adapted to the needs and characteristics of enterprises; essential similarities are the methods, procedures and devices. Considerably modern production systems orient themselves at principles of Lean Production. The term Lean Production was affected in the team by Jim Womack, Dan Jones and Dan Ross in the International Motor Vehicle program. It is known as the MIT Study. The underlying paradigms are process orientation, partaken-cooperative work system design and continuous improvement. In the first part of the lecture Production Systems Lean Production the Lean Production principle is fundamentally introduced. Afterwards the systems and methods of Lean Production will be presented. Last, possibilities for implementing Lean Production systems will be described. L09 Page 2

4 Glossary 5M Method to avoid failures, regarding: Humans, machines, material, method and measurement. 6S Corresponds to the method 6A, is based however on Japanese terms. 6 S stand for Seiri (clearance) Seiton (arrange) Seiso (cleanlineless) Seiketsu (tidiness) Shitsuke (discipline) and Shukan (adaption) Andon Tool for sending information in case of arising problems. Staff member, who discover an error, release a signal, in order to call for assistance (master, colleague) even. Examples are: Andon cord or -button: Thus staff members can stop a band or plant. Andon display panels, inform about the current state of the production. The display refers with light signals to errors at the machine / the system. It serves as central display and should be visible for all staff members. Heijunka [jap.] Production smoothing/ levelled production Jidoka [jap.] Also autonomation (Auto-NO-Mation). Man less machine operation Just-in-time (JIT) Principle for controlling the material and information flow along the entire process chain. The correct part is made available in the correct quality (zero error) to the correct time (exactly, if it is needed) in the correct quantity (a part) of the correct place (where it is needed). JIT supports the pull-principle. Stock should be avoided. In addition it requires a flexible manufacturing with small lot sizes and KANBAN system. KANBAN The meaning of Kanban is translated card. It is a method to control the material flow. If the stock level is below minimum level, the supply is ordered by card or voucher. Kanban is also used for implementing the pull principle. KAIZEN Change (KAI) to the good one (ZEN), thus continuous improvement. The use of the creative potential of the employees is important. Lean Production Optimized processes, which is almost free from waste PDCA-Circle Quality and improvement control loop according to the principle: plan, do, check, action Poka-Yoke [jap.] Poka: random, accidental mistake, Yoke: prevention of mistakes SMED [engl.] Single Minute Exchange of Die: setting-up in less than 10 minutes. Value stream analysis/value stream design The value stream covers all activities and processes (value added and not value added), which are necessary to illustrate a product or service from the incoming orders to the distribution descriptive. Part of the value stream analysis is to retrace the process along the value stream. The method serves for the identification of weak points/waste and for process improvement. The emphasize of the purpose is on the reduction of the turn-around time and the inventories. L09 Page 3

5 Lecture highlights Basic principle and thought pattern in the Lean Production Methods and concepts in Lean Production at Toyota production system Production smoothing Process synchronisation (Adjustment of capacity) Pull-control with Kanban 7 kinds of waste Implementation to Lean Production: value stream design Seite 4 L09 Page 4

6 The way to Lean Production Historical personalities Japanese development Cause effect diagram Beginning of the Toyota production system Extensive introduction Lean Production Kaizen Standardization of Work (Taylor) Control of Quality (Radford 1917, 1922) Quality Control (Sheward) Demings 14 points Western development FMEA Total Quality Control Lean Production Seite 5 In the eighties, due to the upcoming globalization, Western European and American industrial enterprises have been hit at a point they never expect, namely in factory. Analysis showed the superiority of Japanese production concepts, which the locals never achieved. That is why in Japan new products were brought to the market in half of the time and with half of the costs. At the same time the investment in tools and personal equipment in manufacturing sank likewise. First explanation about the Japanese success have been very fragmentary in the beginning. The long work times, the small wages and the high automation found their precipitation in scientific and popular-scientific papers. Intensive discussions were made in the media. The publication by Womack, Ross and Jones at the Massachusetts Institute of Technology (MIT) with the title: the second large revolution in the large automobile industry obtained only the Japanese concept a comprehensive picture of the management for a selected industry. The basis was a comparative study about the western European, American and Japanese automobile industries. The basics of such a succeed were the MIT-study: a comprehensive inclusion of the suppliers, the construction of production-friendly cars, the better training for the workers. The differences were so serious for the European and American competitors that Womack, Jones and Roos spoke about the second industrial revolution. The Japanese enterprises affected the term Lean Production, because they reached with less more. Now the term is also used in different divisions as Lean Development, Lean Management etc. The mechanical-technological attempt by Taylor was the first industrial revolution. The production improvement was reached by the strict separation of the individual work steps, the strict separation from implementing and administering work and by the change from the handicraft to the mass production of few versions. Thereby the circulation of the working sphere and the consumer habits were released world-wide seriously. Rightfully this circulation is called the first industrial revolution. L09 Page 5

7 Contents The principle of Lean Production Systems und methods of Lean Production Conversion to the Lean Production principle Seite 6 L09 Page 6

8 Lean Thinking: Orientation of value from costumers view Processes For which processes does the costumer pay? What is added value, what is not? Staff member and culture How are weak points recognized and used? Which role does the individual coworker take? What does the customer call value? customer process C process B process A supplier Organisation Who can make the best decision? Who recognizes the main problem best? Are the capacity and qualification optimally uses Supplier management How can processes be synchronized in networks in Anl. an Womack/ Jones: Lean Thinking, 1996 Seite 7 The origin of Lean Thinking is basically the value. Value is created by the manufacturers. From the customers point of view, this is the only reason for the existence of manufacturers. Value can only be defined by the final consumer and relies on the value of the specific product (or service) and is basis for the price consumers are willing to pay for the product on the market. This is why manufacturers have to focus on what increases the value of its products and are forced to diminish processes which do not generate surplus value. The first step in lean thinking is to understand what value is and what activities and resources are absolutely necessary to create that value. Once this is understood, everything else is waste. L09 Page 7

9 A typical factory Batch size formation does not correspondent to the customer demand Central planning of all processes Rare delivery of large quantities supplier PPS Weekly planning Daily oder customer Bad performance tuning Daily delivery schedule Supermarket manufacturing Manufac. HRL Supermarket assembly Montage assembly forwarding forwarding Double step of warehouse 3 days 14 days 21 days High stocks 50 days 14 days 2 days 1,5 days 1 hour Push-controlling Multiple handling Turn-around time = 125 days Seite 8 With help of a value stream, individual processes, stock levels and process durations can be illustrated graphically. Entrapments of the value stream are emphasized with so called Kaizenflashes; entrapments can be e. g. very long, unnecessary idle times, which in Lean Thinking corresponds to muda (work). The figure shows a possible value stream of a producing enterprise: Optimization of such a value stream is often organized as workshops integrating all responsible areas for generating improvement activities. The simple Rich Picture symbols help to illustrate the important value stream elements in a simple manner. L09 Page 8

10 Lean Production begins at the customer Orientation at the customer demand Optimization of the own value stream Aspire perfection P customer A C D Value definition from view of customer Definition of the tact of demand Definition of the target value stream Planning of buffers and decoupling interfaces Continuous flow Synchronisation of the cycle time Pull-Controlling and FIFO Production planning in customer-mix Elimination of 7 kinds of waste Standardisation and continuous improvement Fast retooling Autonomous maintenance Protection against errors Production without staff Supplier integration ref. to D. Tapping: Value Stream Management, 2002 Seite 9 L09 Page 9

11 Contents The principle of Lean Production Systems and methods of Lean Production Conversion to the lean Production Principle Seite 10 L09 Page 10

12 Role model Toyota Production System 4 Empowerment & teamwork 3 2 Process synchronisation 1 Source: Toyota Kanban control Production smoothing Highest quality, lowest cost, shortest time Just-in-Time Continuous flow cycle time Pull-System Jidoka Stop and report deviation Separating manual & automatic work Heijunka Standardising Kaizen 8 Stability Visual Management 5 Lean Automation: Autonomation 6 7 Poka Yoke: error safety 7 types of wasting Seite 11 In the fifties the Japanese car manufacturer Toyota turned out into a large crisis: it was to small for the mass car production, because of the powerful competition it could not set a foothold on international markets and on the tiny Japanese domestic market high numbers of items were not to be set off; besides, political defaults made necessary investments more difficult. On top of that money was lacking: workers had just obtained job tenures and thus, because of the high labour costs, means for purchasing important tools were lacking. The corporation would have gladly built cars according to tayloristic principles, but it could not afford a press line, so that parts were manufactured on one press. Thus virtue arose from hardship and a philosophy from dealing with insufficiencies. Instead of classically isolating the production steps and processing them in sequence, Toyota built all decisive steps on the way to the product around this core. Trough close interlocking of process steps and team work, turn-around times were shortened and error ratios were reduced, thus considerably lowering costs. Quality is no longer a station it is part of every process. The integrated production method loosened the interdependencies of time, quality and costs and broke trough the old vicious circle of tayloristic mass production. Up to that time more products were built by means of faster work flow, meaning shorter process steps, which inevitably led to higher complexity of work an so to higher costs. The Toyota Production System broke this chain and revolutionized production all over the world. Today the Toyota Production System and its methods are world-wide considered a benchmark for producing enterprises. L09 Page 11

13 1) Production smoothing as a base for stable processes Acquisition Production Market demand Pull Quantity Buffer Quantity Time Time Synchronized supply chain Stable capacity requirement Uncoupling of short term demand fluctuations Pre-requisite for production smoothing: small lot size Product A Product A Cycle time after Drew: Journey to Lean, 2004 Stock Product B t Product B Product A t Product B t Product B Product A t Seite 12 In an ideal world, companies would build their products to order in exactly the sequence that it received the orders. The reality is that variable work content or differences in the total amount of time it takes to build different products makes this impossible and demands a compromise, which is achieved through production leveling. In production leveling, the true demand is artificially smoothed; thus stable and changeless working conditions are ensured. These are mandatory premises for standardization and high capacity utilization. The concept of production smoothing is to diminish as much as possible the quantity variance in a production line. Although the demand for products can change widely e.g. because of seasonal aspects thus affecting monthly production volumes, production smoothing allows daily production volumes to remain constant. L09 Page 12

14 2) Process synchronization as a base for high capacity utilization Initial state Final state Cycle time [min] Tact time Waiting time Cycle time [min] Tact time Pacemaker A B C D E Employee Pacemaker AB CD E Employee Trough load balancing of the processes capacity requirements are synchronised and workload is optimized Every process has only one bottleneck (pacemaker), this controls the entire process: upstream as pull and downstream as FIFO-push Source: Tapping: Value Stream Management, 2002 Seite 13 Takt is the German term for the beat or rhythm of a piece of music. Takt time is defined as the total available time for production divided by the total customer demand for that period. Takt time is designed to optimise material flow in pursuit of Just-in-time delivery to the customer. This is done by setting the pace of production at the rate of demand, thus eliminating the risk of overproduction (which in the world Lean Production deems the worst type of waste since it hides and also causes other types of waste). Process synchronisation is used to balance work content in a continuous flow line, which often has the effect of reducing the amount of labour needed to build a product. The normal approach is to balance all but one of the workstations to Takt, leaving the remaining workstations (Operation AB and E in the figure) with a lower work content. In the short term, the spare capacity of operation AB and E provides flexibility for dealing with any problems that occur during the production cycle. Due to the fact, that customer demand varies significantly from period to period companies have to revaluate Takt time in each period to ensure that customer demand is always met. As rebalancing lines and retraining people often result in a massive efforts, adoptions should be made no more than twice a year to ensure that changes are manageable. L09 Page 13

15 3) Kanban for autonomous material control according to the pull principle Regular customer Production Kanban Finished parts stock Delivery Kanban Finished parts stock Supplier process Product Customer process Kanban board: defined work in progress stock Assembly line Part or material ordering for the lines Warehouse for finished parts Prefabrication lines Material allocation at the lines Assembly Prefabrication Assembly Kanban Part production Kanban Signal Kanban for buffer stocks Parts warehouse Acquisition parts Kanban Source: Takeda 1996 Suppliers Seite 14 Kanban (or production Kanban) is a method of controlling a process or part of a process of a JiT production. Centre point of this control principle are the cards (kanbans), assigned to the product variants, that trigger the production order. A kanban represents a certain batch (according to the packing unit). At the end of the process there is a filing for the various kanban cards. The number of cards of a product variant in this filing gives clue to the priority of the production of this variant. The card is removed from the storage at the beginning of the production of a product variant an wanders with the lot trough the process in a buffer storage to the end of the process. The customer of this process takes his ware from the buffer and puts the kanban back in the filing. Because of the fix number of cards a Kanban control method makes sense only for balanced production quantities. Another version of the production Kanban is the transport Kanban. This controls the material transport between warehouses and/or production sites. Kanban is favourable for a JiT production because it complies with the demands of pull control, demand driven production, small lot sizes and visualisation and is simple, clearly laid out and self controlling. L09 Page 14

16 4) Empowerment and teamwork Classic system Efficiency trough formalization and standardization Tayloristic division of labour Central planning & organizing Execution and control parting Example: Ford 1920 Autonomous working groups Example: Volvo Uddevalla 1980 Efficiency trough incentives and involvement Integration of surrounding field activities Job rotation Capacitive levelling within the group Standards as Temporary Best Practice Seite 15 A form of the decentralization particularly relevant for the operational organization in production are team work concepts. In production tasks are only accomplishable by means of intense interaction of more co-workers of different qualifications. The thus resulting coordination effort is minimized by forming self organized teams that can perform a specific task completely. Compared with a classic organization, in which everyone receives exact description of work, in teamwork a task is assigned to several persons, who reach the task fulfilment independently. Teamwork is usually associated with incentive pay to balance the growing responsibility. A typical trait of the various types of teamwork is the degree of autonomy. The first step is the responsibility for one owns work and continues over training responsibility and responsibility for indirect activities (machine maintenance) to personnel, meaning co-worker, responsibility. Teamwork concepts took hold of almost the entire production field of the automotive industry. Also more and more companies of the machine and facility building industry are switching over to such work concepts. L09 Page 15

17 5) Lean Automation - Autonomation Components Maximize equipment efficiency Examples Elimination of idle travelling Eliminate of Handling and Transport Motion optimization (e.g. faster feed) Build cheaper equipment Machine size should match product size Workplace merging Match machines to the flow Consideration for quantity proportion Cycle time production Simplify retooling Splitting of internal and external retooling Fast clamping fixtures Outright production of GO parts Error autonomy Machine stop at malfunction Securing all machining steps Source: Takeda 1995 Seite 16 Autonomation is a process designed to allow a workforce to detect production problems quickly and resolve them decisively. Its objectives are to improve equipment reliability, enhance product quality and increase productivity. It consists of three elements: Detect and stop: The most effective method of detecting a fault or abnormality is to give the responsibility to the people who operate the process. Alert: Once a problem has been detected, the process or the operator needs to alert the team leader. This can be done verbally, by means of an Andon board (a display that indicates production status), or via an audible alert. Root-cause problem solving: Even if it isn t possible to rectify the root cause immediately, it s important to take action to contain the problem before the process is restarted. It may be e.g. that an additional check needs to be made on every component until the source of an intermittent fault upstream in the process has been identified and addressed. L09 Page 16

18 6) Poka Yoke for failsafe working Poka Yoke Failure safety Trigger mechanisms Regulation mechanisms Contact method Fix value method Step sequence method Intervention method Alarm method Group identification Deviation from geometrical parameters Deviation from the number of work steps Controlling the standard movement sequence Stop at irregularities Signals that point to human error Self control able groups Part Part holder Process A Process B Link e.g. geometrically distinct e.g. Controlling the part holder number of screwing operations e.g. Process linking prevents human errors e.g. Andon-rope to halt production line e.g. Pick-to-Light e.g. quality circle, for rack unloading control Mutual examination of the group Seite 17 Poka Yoke (jap. avoiding unintentional mistakes) stands for the usage of fail safe equipment in the production process. Poka Yokes are supposed to protect the machine operator from human errors in an easy way. Special attention is paid to the workers participation and to their errors in the production process. The aim is to avoid product defects caused by human errors such as inattention, stress or misinterpreting, due to cumbering working environment or poor working conditions. An example is part scanning, which ensures the correct placing of the part in the machine by analysing its shape. In Poka Yoke systems the basis elements of initializing and triggering mechanisms are differentiated from the regulation mechanism. Another important element is team work (quality circle). On one side it improves Poka Yoke systems, on the other side teamwork is being improved by Poka Yoke. To prevent error repeating, error source inspections are made in combination with Poka Yoke. By using this two principles errors can be suppressed efficiently and effectively. L09 Page 17

19 7) The 7 types of wasting (Muda) in Lean Production Equipping Screwing together Welding Pressing Varnishing Stacking parts Removing packing material Removing chippings Encompassing part acquiring paths Activities that add value Value adding work katakana muda Waste that can be eliminated straight away Wasteful works that must be done Worker movements Work Non value adding work hirigana muda Kanji muda Waste caused by the facility or machine Bringing back to start position Cleaning supply areas Holding keys and switches Manual operation of machines Idle ways at hydraulic or pneumatic powered tools To long feed paths Oversized machines Ref. to Takeda 1999 Seite 18 The figure shows the three levels of waste in Lean Management. The first level is katakana muda. It can be identified easily and has to be eliminated straight away. The second level is hiragana muda. It contains the largest part of non value adding work. The third level of waste is kanji muda. It represents the type of waste made for example by overcapacity that is used at full power regardless cycle time. Other examples include long feed paths to the part and a worker spectating to such operations. There are 7 Muda in total: Muda trough overproduction Muda trough waiting times Muda trough transport Muda at the machining Muda trough stock keeping Muda trough unnecessary movements Muda trough the production of bad parts L09 Page 18

20 8) Visual management as a control and leading instrument Factory informations Achievement of objectives Advice and warning signs Product and storage location tag Standardized worksheets Status displays and Andon-Board Error prevention displays Area marking Process oriented layout Ref to. Monden 1994 and Ohno 1993 Seite 19 Visual management is the communication basis of the Lean Production system and thus a key component. Three important aspects of visual management can be distinguished: Communication of information: direct or indirect sharing of your work data with co-workers to stimulate their intellectual contribution Communication of work standards and procedures: explicit knowledge documentation of work relevant data Visual configuration of workplaces and processes: creating an overview which allows the recognition of any deviation from the OUGHT TO state. This implies the setting of OUGHT TO states Within the Toyota Production System the 6S-rules are the basic fundament for visual management (see L9 page 20). L09 Page 19

21 Contents The principle of Lean Production Systems und methods of Lean Production Conversion to the Lean Production principle Seite 20 L09 Page 20

22 Value stream design: The current tool in Lean Production Structure of methodology ABC GmbH Tuesday + Friday Select product family Group of products at the end of the value stream Basis: Similar processing steps and machines equipment Customer or supplier (external) Design of the actual state Rough outline of material and information flow Analysis and comprehensive of the current function of the factory Production planning MRP Information flow Design of the target state Draw the attainable, future value stream in twelve months Basis: Basic rules of Lean Production Systems Electrical information flow conversion Provide a plan of value stream (year shedule) Gradual conversion Continuous adjustment and examination of the desired value stream Fa. Cologne Truck supply I Pressing I assembly I 4 x / day Stock (quantity and current value notes) Ref to. Rother 2000/ Erlach shifts Circle time Retool time delay (%) Material PUSH (push forwarded) 2 shifts Circle time Retool time delay (%) Process case Data case Seite 21 Value stream means all activities (as well as added value and not added value), which are necessary to bring a product from the raw material to the hands of the customer. Value stream design represents the whole value stream to improve it afterwards. Thus it designates a method for the improvement or organisation of the process steps. Material as well as information flows and temporal coupling of the production steps are regarded together, in order to achieve a comprehensive optimisation. The procedure in the value stream design can be summarized in the following way: Directly in the production the value stream is noted with simple pictures and symbols. The symbols are arranged that everyone understands the value stream without individual training. The analysis of value stream always begins with the supplier and ends at the costumer of the current production process for one division. After the admission of the actual condition the elaboration of an improved specified condition follows. The methods offers some fundamental suggestions to improve the value stream. Suggestions are the avoidance of material stocks by introducing the continuous flow production or by introducing the decentralized control structures. L09 Page 21

23 Example: Process optimisation with the value stream principle Before After supplier Production controlling costumer supplier Production controlling pacemaker costumer forwarding forwarding A B D A B, C & D C 6d 90s 5,4d 180s 2d 30s 1,4d 3d 90s 1d 190s 1d All processes are planned centrally Push-controlling Processes are secured by stocks Turn-around time: 300 seconds + 14,8 days The pacemaker controls all processes Supermarket und Kanban-controllling Capacity leveling within working group Turn-around time: 280 seconds + 5 days Seite 22 L09 Page 22

24 6S Order & Cleanlineless: Problems, nobody see, do not disturb Step 1 of the conversation Seiri: Separation of required and not required units. Units which are not in use, have to remove immediately. Seito: The necessary units have to stand on comprehensively defined places. Everyone must have a good access. Seiso: Thorough cleaning What s wrong with this? Step 2 of the conversion Seiketsu: Keep the condition created before Step 3 of the conversion Shitsuke: Accomplish the work in the correct way Shukan: Internalise the learned and standardised Ref. to Takeda 1999 Seite 23 6S comes from the Japanese and stand for Seiri (clearance), Seiton (arrange), Seiso (cleanlineless), Seiketzu (tidiness), Shitsuke (discipline) and Shukan (adaption). It describes the tidiness and cleanlineless at the working place and in the whole enterprise. However 6S is more than keep the working place clean; it is an attitude of mind, which affects very positively the quality of the staff members and of the products. The 6S is a basis for the introduction of a synchronous production system, just like standardisation and visualisation (or visual management), which are linked closely with the topic 6S. Exemplary statements supporting the implementation of of 6S: As long as the ways are dirty, improvement is still needed With dirty clothes you produce bad products It is important to copy good things L09 Page 23

25 Example: Optimized sidewalks & utilization of capacity in U-layout Example 1: 3 Capacity steps of an manual assembly 1 coworker Example 2: Operation of several machines in the manufacturing coworker coworker Seite 24 In manufacturing area, by arranging machines in product-oriented layout (instead of a functionoriented arrangement), the flow-principle can be supported (example 2). The U-Layout gives the following advantages: Multi-machine operation in coherence with short routes. High communication and, thus, simplification of the mistake-search and adjustment Consolidated area usage Scalability (e.g. in case of fluctuant volume) L09 Page 24

26 Example of optimization of setup time (SMED-principle by Toyota): Separation from internal and external activities A B C Activity consisting of individual components Tcritical Identification of activities, which can be realised preliminary Tcritical Reorganisation of the activities Coverage Setup procedure Machine maintenance Adjustment procedure... Proceeding Group of few people revises the expiration of an activity according to the steps A-D. Survey of the result. Adaptation or extension of existing standards D Tcritical Optimization of the remaining activities Tcritical caption: Tcritical Required period for the principle activity Activity, which is realised during the critical time Activity, which is preliminary implemented Seite 25 The term SMED is an abbreviation for Single Minute Exchange of Die. This represents a method to minimized system stops which are caused by setting up procedures. The method and term SMED derives from the Toyota Production System. There the downtime presents a success-critical factor as a result of tool changes in the context of the Just in Time manufacturing of small lot sizes. The method can always be used, where time-critical, standardised activities (e.g. at intensive investment plants) must be accomplished (e.g. retooling procedures, maintenance work or material assembly. L09 Page 25

27 Example: CI - workshops CI - Workshops in production are accomplished as group activity and as comprehensive functions. e.g. long sidewalks in a work station of a machine assembly The expiration is oriented at the PDCA cycle 1. Admission of the actual state in production 2. Systematically search for weak points: The 7 kinds of waste 3. Creative identification of improvement measures 4. Conversion still in the Workshop 5. Documentation and monitoring of the new standard, pursuit of long-term measures Measures, e.g.: Improvement of the material supply golden-zone Reorganisation of work contents Change of the work contents 1 touch -assembly CI = Continuous Improvement Seite 26 L09 Page 26

28 Continuous improvement (Kaizen): Example from the Ford Production System Productin planning and control Warehouse reduction & KANBAN Abbreviation of setup time Training matrix reduction of the downtime Standard work instructions CI Planned maintenance 6 S Automobiles maintenance 4 principles of visual Warehouse control traceability & Control of lot size Source: Ford Seite 27 A substantial aspect of the concentration of added value in the Lean Production is the continuous improvement process (jap: Kaizen). The main objective of Kaizen is the elimination of the 7 kinds of waste. Kaizen is not only a high management instrument; in fact Kaizen motivates workers to revise all processes critically. With help of Kaizen, companies engage their employees to have an acute eye on all unproductive, not value creating processes This is done by Kaizen workshops, circles or Kaizen suggestion systems. Target is the fast, unbureaucratic detection of easily transformable activities. L09 Page 27

29 Lean Production: a challenge for the culture in the enterprise Lean Thinking Flexibility is more important than efficiency (Scale) Added value results from the production staff member, indirect spheres are service provider Everyone should understand, how its work contributes to the company s targets The causes of problems must be addressed, not only the symptoms A problem is a chance for improvement Lean - Behaviour Decisions are made as a result of long-term, systematic considerations The management is closely connected to the reality of everyday life in the production, the Gemba The production coworkers are really involved in improvement activities Manager work to solve system problems There is an open dialogue between the colleagues of all levels. source: John Drew: Journey to Lean, 2004 Seite 28 L09 Page 28

30 Production Systems of different enterprises Arbeitsstrukturen Work structures and und Gruppenarbeit teamworkt Standardi- dization sierung Quality Qualität as im Mittelpunkt focus Just in Time Kontinuierliche Continuous Verbesserung improvement Leading Clear tasks and roles Participation and development of colleagues Structure in working grpoups Job safty and Environmental awareness Standardized methods and processes Visual management/ 5A Fast identification of problems and error correction Stable processes/products and Preventive quality management Costumer orientation (internal & external) Production smoothing Pull production Fließfertigung Taktfertigung Remove of waste 92 Vertiefende detailed MPS MPS-Methoden methods und und tools -Werkzeuge Visualisation and Standardization Labour organisation and personal management Hire principle (bonus wages) CP KVP colleagues Assembly and manufacturing places Zero-defects concpts Total Productive Maintenance- TPM Material supply Just-In-Time Order and cleanlineless (5-S) Seite 29 Methods, instructions, methodologies, work standards but also company-cultural aspects are structured in a frame: the Production System. The Toyota Production System (TPS) is meant to be exemplary to the automobile industry. Today, nearly every company has got its own production systems, adapted to the individual organization, culture and company structure. The Mercedes-Benz Production System (see figure upper right) consists of 3 levels. 5 basic elements form the roof, which is carried by 15 production principles. The fundament for implementing these principles is supported by altogether 92 methods, tools and rules. L09 Page 29

31 List of litarture Askin an Goldebrg: Design and Analysis of Lean Production Systems. J. Wiley, New York 2002 Drew, J.: Journey to Lean, Making operational change stick, Großbritannien, 2004 Erlach, K.: Mit Wertstromdesign zur schnellen Fabrik, Stuttgart 2003 Görgens, J.: Just-in-Time Fertigung: Konzept und modellgestützte Analyse. Schäffer-Poeschel Verlag, Stuttgart 1994 Imai, M.: Kaizen: Der Schlüssel zum Erfolg der Japaner im Wettbewerb. 7. Auflage, Wirtschaftsverlag Langen Müller/Herbig, München 1992 Jansen, H.H.: Lean Production in der mittelständischen Industrie. Springer Verlag, Berlin 1993 Mehdorn, H., Töpfer, A.: Besser-Schneller-Schlanker: TQM-Konzepte in der Unternehmenspraxis. Hermann Luchterhand Verlag, Neuwied, Kriftel, Berlin 1994 Mondon, Y.: Toyota Production System An Integrated Approach in Just-in-Time, London 1993 N.N.: Lean Management. Der Weg zur schlanken Fabrik. gfmt, St. Gallen 1993 N.N.: Lean Production. Tragweite und Grenzen eines Modells. Fachtagung, RKW, Eschborn 1992 Ohno, T.: Das Toyota-Produktionssystem. Übersetzung von W. Hof. Campus Verlag, Frankfurt 1993 Pfeiffer, W.: Lean-Management: Grundlagen der Führung und Organisation lernender Unternehmen. Erich Schmidt Verlag,Berlin 1994 Reingold, E.M.: Toyota. People, Ideas and the Challenge of the New. Japanese Business, Peguin Books, London 1999 Rother, M.: Learning to See, Brookline, Massachusetts: Lean Enterprise Institute, 2003 Sekine, K.: Produzieren ohne Verschwendung. Der japanische Weg zur schlanken Produktion. Japan Service, Verlag Moderne Industrie. LandsbergLech 1994 Stürzl, W.: Lean Production in der Praxis: Spitzenleistung durch Gruppenarbeit. Junfermann Verlag, Paderborn 1993 Takeda, H.: Das synchrone Produktionssystem. Just-in-Time für das ganze Unternehmen, verlage moderne industrie Landsberg, 1999 Tapping, D.: Value Stream Mamagement for the Lean Office, New York 2002 Wildemann, H.: Lean Management: Strategien zur Erreichung wettbewerbsfähiger Unternehmen. FAZ Verlagsbereich Wirtschaftsbücher, Frankfurt a. Main 1993 Womack und Jones; The machine that changed the world, Rawson Associates, New York 1990 Womack und Jones; Lean Thinking, New York 1996 L09 Page 30