Reduction of 7 Waste.ppt

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THE 7 WASTES What are they?

Transcript of Reduction of 7 Waste.ppt

  • THE 7 WASTES

    What are they?

  • THE 7 WASTES

    * Over Production* Waiting* Transportation* Over Processing* Inventory* Scrap /Rework* MotionITS

    DOOMSWIM

    TOO

  • OVERPRODUCTION*Overproduction occurs when product is manufactured in excess of customer demand or in advance of customer demand.*Overproduction :-

    - Uses resources unnecessarily (people, material and machines) - Creates unnecessary inventory - Contributes to other forms of waste

    *Machine maintenance and improvement activity cannot take place whilst machines and associates are overproducing.

  • TRANSPORTATION*The transportation of material or parts adds no value but requires :- - extra resources (in terms of people material and equipment) - management - temporary storage locations.*The more a part is handled the more likely it is to be damaged.*Transportation of material leads to increased inventory & delays elsewhere in the manufacturing process.

  • WAITING*Waiting occurs when either material or operators wait for machines to complete cycles of work. *Modern machines generally do not require associates to watch them whilst in automatic operation.*Utilise waiting time by combining operations, carrying out sub- assembly operations, quality checks, feeding material to colleagues etc.*Call for help if you have to wait for material or machine breakdowns.*Any waiting time in an assignment means there is a need to improve the process and review the work balance.

  • INVENTORY*Inventory is any quantities of parts or material held within the system which are not being worked on.*Covers for unresponsive and unreliable processes*Increases lead time. *Longer to introduce engineering changes and improvements.* Takes up floorspace, requires management, ties up cash.*FIFO becomes difficult, material can become obsolete.*Product can become damaged or contaminated.

  • OVERPROCESSING*Where resource or effort is applied to a product or process that adds cost but no value for the customer.*All product characteristics should have customer derived specifications and acceptance criteria.*All process equipment should be specified to be capable of consistently satisfying customer requirements - not substantially exceeding them.*Any process with subjective acceptance criteria should have pictorial standards displayed lineside.

  • SCRAP / RE-WORK*Any manufactured product which does not meet customer requirements after the normal process, is waste.*Poor process discipline, inadequate training, poor design of facilities and equipment, poor levels of process stability & capability, careless handling of material, can all contribute to this form of waste.

    *Rework is often viewed as a lesser evil but, within the KPM system, the time spent reworking defective partsmeans the loss of further good parts from the process.*All management & associates must adopt the view that defects are not inevitable, they can and must be avoided.SCRAPREWORK

  • MOTION Any motion by operators or machines when carrying out cycles of work which does not add value is waste.

    Even the best processes require some motion by operators or machines which does not strictly add value - this is also waste, but is referred to as incidental motion.

    Incidental motion is that which is necessary within the current process design, such as taking parts from a pallet, loading & unloading, machine start, etc.

    Any other motion, such as walking, reaching, lifting & lowering is total waste. All motion must be minimised.

  • Chart Showing Waste in MotionTotal wasteNon value added motionIncidental motionNecessary motionunder present job conditionsValue added motionActivity that changesthe form or shape ofthe component in a desirable way

  • Standardise ProcessRe-design ProcessIdentify WasteRe-balanceELIMINATING WASTEWASTE IDENTIFICATION & ELIMINATIONA Five Stage Approach to Waste Elimination1.Map the process.2.Identify the areas of waste.3.Re-design the process, reducing or eliminating the waste.4.Standardise the process.5.Review the work balance for further improvement.Map the Process

  • PROCESS MAPPING TRANSPORT

    VALIDATION PROCESS STORE DELAYAll elements of the process are closely studied and allocated one of these ASME symbols. The process map helps to identify what is value added activity and what is not.From a customer viewpoint, Process is the only element which adds value, the rest are waste.Some of the activity within Process will also be waste.

  • 5 Hubs1mHoistProcess Mapping / Waste Identification - BeforeTorqueovercheck3mCarryD/shaft4mHoist37DriveshaftsStartNut StartAutoNut-runnerStakenutMark nutFitD/shaftto hub& Torqueovercheck4mHoist7 Parts21 Parts17mTrolleyFitD/shaftTo Engine4mHoist

    4m2s +(12s)2s4s 4m6s 1mSummary of ProcessTotal manual time96 secsTotal WIP 34 partsLead time 51 minsDistance travelled33 mValue Add Ratio 5/19 = 26%4m12s17m6s3m1Part537721

  • Dept : Payroll Activity : TimesheetsCOLUMN TOTAL 2 (A)VALUE ADDED RATIO = (A) = (B)No.DescriptionFlow ChartOwnerComments1.2.3.4.5.6.7.8.9.10.11.12.

    TOTAL No. SYMBOLS 12 (B)Collect sheetsPut into envelope, label, and asideTake envelope to post room and return to PayrollTime sheets posted to each managerManager opens mail and asides sheetsManager completes and returns sheets for dept.Walk to post room, collect post, return to PayrollSort and open post, place sheets in pending trayGet authorisation signature from senior managerSort into order and check dataTransfer onto PCFile sheets for future referenceProcess Mapping / Waste Identification Sheet

    DMeasure

  • 1Part2mHoistProcess Mapping / Waste Elimination - AfterTorqueovercheck1mfetch d/shaftready to fit37PartsStartNut offStartAutoNut-runnerStakenutMark nutFitD/shaft& TorqueovercheckFitD/shaftTo Engine4mHoist2s +(12s)2s3s2mSummary of processBefore After ImprovementTotal manual time96 secs 56 secs 41% reduction Total WIP 34 parts 2 parts 94% reductionDistance travelled33 m 7 m 79% reductionValue Add Ratio 26% 42% 61% increase 4m16s6s1m1Part137

  • STARTFINISHBEFORE - high level of wasteAFTER - reduced wasteABCDEFRe-design the Process - Stage 1 ABCDEFRe-design Process

  • Parallel Line ConstructionBEFOREAFTER ABCDEF ABCDEFWasted motion Minimal wasted motion Increased labour flexibilityWasted motionRe- design the Process - Stage 2Re-design Process

  • Work Instruction ChartStandardise the ProcessStandardise ProcessNO.WORK DESCRIPTIONKEY POINTSSKETCH12345678OPEN MACHINE DOORROTATE THE CHUCK UNTIL CLAMPS ARE RELEASEDREMOVE COMPONENTS AND PLACE TO THE SIDE OF THE MACHINEOBTAIN RAW MATERIAL AND PLACE IN CHUCKLOCATE CLAMPSCLOSE MACHINE DOORSPRESS START BUTTONSTRANSFER COMPONENTS TO THE NEXT STAGEENSURE MACHINE CYCLE HASBEEN COMPLETEDENSURE HANDS ARE CLEAR OFCLAMPSENSURE FLANGE FACES HAVE BEEN MACHINEDENSURE HANDS ARE CLEAR OFCLAMPSREVISIONAPPROVED BYDATEREVISED BYONEA.B19.10.95B.CKNACKSAFETYQUALITYUSE RIGHT HAND & TWIST TOSEAT IN CHUCK

  • Loading Operators to Required Cycle Time (Takt Time)Look for alternative operation sequences to load as many operators as possible to Takt Time, to prevent over-production - which is waste.This also accumulates waiting time (waste) and makes it more visible.BEFOREOp.1 30 secOp.2 10 secOp.8 10 secOp.7 5 sec55 s55 s01020304050607080SecondsOperator 1 2 Takt = 70 secsAFTEROp.1 30 secOp.2 10 secOp.8 10 secOp.7 5 sec12653470s40 s01020304050607080SecondsTakt = 70 secsOperator 1 2 Re - Balance the ProcessRe-balance

  • SummaryIs the core activity at the heart of Lean ManufacturingEvery element of Lean Manufacturing pursues waste elimination.Many western businesses have overall levels of waste of up to 50%.World class businesses have levels of waste of 20% or less.Lean Manufacturing makes waste continuously visible.All associates must continuously pursue waste elimination.Waste EliminationImportance of Waste Identification & Elimination

    * Key Points

    It is generally accepted that there are 7 main types of waste which can afflict most processes. (Why 7? 7 is a lucky number to the Japanese, which explains why there are 7 tools of quality, 7 management & planning tools, etc.) Ask the candidates what the 7 wastes are!

    Write their answers on a flip chart or Nobo board.

    These were originally mentioned in the overview presentation and in the videos.

    These wastes offer the major opportunity for improvement in the workplace.

    Identifying these wastes is a key step in continuous improvement.

    4.1.2* Key Points

    It is generally accepted that there are 7 main types of waste which can afflict most processes. (Why 7? 7 is a lucky number to the Japanese, which explains why there are 7 tools of quality, 7 management & planning tools, etc.) Ask the candidates what the 7 wastes are!

    Write their answers on a flip chart or Nobo board.

    These were originally mentioned in the overview presentation and in the videos.

    These wastes offer the major opportunity for improvement in the workplace.

    Identifying these wastes is a key step in continuous improvement.

    4.1.2*Key Points(If you order 2 meals in a restaurant, you would think it a waste if 3 meals turned up or if all 3 courses arrived together!) Stress that overproduction is the worst form of waste, as it directly contributes to other forms of waste. Over production occurs when components or material are produced at a greater rate than customer demand or when they are produced in advance of customer demand. There are usually 3 main causes of over production; 1) Inappropriate business measures which encourage production without demand.2) Where the customer requires more flexibility or a faster response than the process can provide. (leading to production in advance of demand)3) Where process reliability is poor. (leading to production faster than demand to cover for down time) Normally the maximum rate of output from any process exceeds customer demand and will therefore allow the process to overproduce unless there are strict production control rules and other physical constraints which prevent this. e.g. single piece in-process stock holders, defined levels of shop stock, limited number of kanbans & operators loaded to takt time.

    4.1.4*Key Points(We would all like our place of work to be just around the corner from where we live, to cut down travel time & cost - which we can see as waste.) Many manufacturing processes and systems have evolved, over time, into layouts that would probably never have been planned that way! Successive process elements are not located next to one another, which means that components must be moved - transported - from one location to another, which adds cost to the product but no value for the customer and is therefore WASTE! If products have to be transported from one workplace to another, this invariably leads to other forms of waste - such as increased inventory. e.g. a quantity of material waiting for transport, a quantity being transported and a third quantity which has just been transported - treble the normal inventory!? Process mapping highlights the level of wasteful transportation in a process and will also show the high level of inventory. Process mapping will not show the amount of management required to plan & control the transportation itself nor the increased difficulty in managing the actual manufacturing system that results from excessive product transportation. Locating successive stations of a process close together greatly reduces the waste caused by transportation - and is usually not too difficult to accomplish.4.1.5*Key Points (Most people dont like waiting in their own time for goods and services - they can immediately see it as waste! Why accept it at work ?)Operators or material waiting for machines to complete cycles of work reduces their level of utilisation and therefore adds unnecessary cost but no value to the product - waiting is WASTE.The best companies in the world try to obtain maximum utilisation of; - labour, - material, - & machines, usually in this order, since over the life of a product the labour costs are likely to be the highest.Many western companies focus on maximum machine utilisation and ignore labour and material utilisation. Many western companies are happy to have operators waiting for machines - if this means machines can be kept running all of the time. The best companies in the world will never have operators waiting for machines, but are more comfortable to have machines waiting for operators - if this means fully occupying operators time with value adding activity. One of the tools of Lean Manufacturing - loading operators to takt time - has a specific objective of making operator waiting time more visible, to focus management attention on the need to improve and rebalance that process.4.1.6*Key Points (At home, we keep the minimum quantity of food and drink in our fridge's and cupboards to keep us going until the next opportunity to visit the supermarket. We do not try to keep a months supply of milk or eggs or cornflakes. Why? Because it takes up a lot of space, costs money to maintain (if in a fridge) and ties up our hard earned cash! We can easily see that unnecessarily large stocks of food & drink are wasteful. Why do it at work?) The main reasons for unnecessarily large stocks of material or components in manufacturing processes are;- Process unreliability, leading to the need to hold stock to cover for periods of down time.- Poor process responsiveness, leading to the need to hold large stocks of every variant to satisfy customer demand from stock to cover for excessively long and expensive equipment changeovers.Excessive inventory will increase the manufacturing lead time - the time taken for products to pass from raw material to finished goods.Increased lead time means slower introduction of engineering changes and process improvements - because all the old product must be purged from the system before the results of the changes can be seen & validated.Excessive inventory also means more product at quality risk. Often quality defects are discovered at the next process - increased inventory means more product between processes, so more product at risk.4.1.7*Key Points (Does a cup of tea with milk and sugar continue to improve if you stir it for 10 minutes? No! Some stirring is required, but after about 10 seconds any further stirring would be putting in effort which would not add any value to the consumer - it would be waste. The same principle applies to manufacturing processes.) We need to be careful not to allow the waste of overprocessing to be seen as being in conflict with many companies objective of exceeding customer expectations. If additional processing would add value to the product for the customer - then it is not overprocessing, even though it may exceed the specification. The criterion for overprocessing is adding cost but no customer value. Ask the audience to give some examples of overprocessing. Write them on a flip chart or nobo board and discuss them. This is quite a subtle concept to grasp - but important. Many processes expend resources and incur high scrap costs pursuing product standards that exceed the specification and would add no customer value. There is a technique called Quality Function Deployment which can be used to evaluate products and processes against customer requirements to help minimise over specification and over processing. 4.1.8*Key Points

    Scrap & rework invariably result from human errors within the manufacturing or support processes. 3%, 2% or even 1% defect rate might not sound too bad - but if applied to air traffic control operations would mean over 100 near misses (or worse) per day, just over Britain - which would be totally unacceptable. The same standards should be applied to manufacturing. Defects should not be considered to be inevitable - they are not! The best processes in the world are now operating at defect rates of less than 25 defects per million components produced. Any level of scrap or rework above this figure is unnecessarily wasteful and is unlikely to be competitive. The first step towards reducing scrap or rework is to make it VISIBLE to all associates and management - to help focus attention and resources. Process standardisation and process discipline is another important factor. The attentive use of statistical process monitoring should lead to improved process stability and capability, which should mean zero defects. In-process defect control (poka yoke) is another effective tool in preventing defects being passed onto the next process. The most important factor is the culture and attitude of the whole company - Zero Defects passed forward must be an objective which is vigorously pursued by all.4.1.9*Key Points

    Any motion by operators or machines costs money and consumes resources - therefore, any motion which does not add value to the product is waste. The whole purpose for employing operators and machines is for them to move and usually this includes moving the product from pallet to bin, from bin to machine and from machine back to bin or pallet. Some of this movement of product, operators or machines may be essential for the process to function - but if it does not add value to the product, it is waste. All motion of operators and machines should be minimised - minimised motion helps towards minimised waste in the process. Even those movements which are absolutely essential must be arranged to obtain maximum process value. The Principles of Effective Motion include; - Minimum movements-Rhythmical movements - Simultaneous movements- Habitual movements - Symetrical movements- Continuous movements - Natural movements Any motion by operators or machines which is not adding value and is not absolutely necessary - is total waste and must be eliminated. This usually includes walking, reaching, lifting, lowering, turning, etc. Within a flexible manpower system, increased walking is sometimes traded off against reduced:- overproduction, inventory, lead time, transport & delay.4.1.10*Key Points

    The slide shows typical proportions of Value added motion, Incidental motion and Totally wasted motion. As much as 70% of overall motion is not value add, with around 35% being total waste. This highlights how important it is to reduce motion to the minimum. How can this be done? Ask the audience to suggest ways to minimise motion within their processes. Write their suggestions on a flip chart or board & compare them with the list below. Layout connecting processes to minimise walking. Place material as close to the point of use as practical. Use small, end user containers which can be designed into the workstation and replaced or refilled frequently. Hang or suspend tools as close to the point of use as possible. Ensure associates have a logical sequence of work. Design workstations to encompass minimum movement. Ensure all material has a lineside location within the normal range of movement of the operator.4.1.11*Key Points

    This presentation covers the application of the process illustrated, specifically to waste elimination in an operator/machine manufacturing process - but the basic principles would apply to waste elimination in any process.

    Map the Process - Process Mapping is a particular style of process study which uses the ASME symbols to identify the process lead-time and exactly which elements of the process contribute what proportion of that lead-time. This enables the identification of the major areas of non-value add activity, (waste) and some of the reasons.

    Within KPM, Process Mapping also examines the actual operator/machine activity in great detail - which enables the further identification of waste, even within the value-add portion of the overall process.

    The identification of waste comes directly from the detailed process mapping exercise.

    Process re-design is achieved through the application of the key principles of KPM or Lean Manufacturing, viz. Just-in-Time, Autonomation & Flexible Manpower System. This re-design creates a process with much lower levels of waste.

    Standardisation is essential if the new way of working is to stabilise and provide a firm foundation for future kaizen (continuous improvement).

    Workload Re-balancing (between process operators) enables the saving of wasted process effort to be converted into savings in the resources required by the process.4.1.12* Key Points

    The ASME symbols are used worldwide. ASME stands for the American Society of Mechanical Engineers. Process mapping is an essential tool, which helps us to fully understand the process. Once we have that understanding, the major areas of waste within the process become easier to identify. Within the process map, only the process symbol represents value added working - and with closer examination, some of this activity can also be identified as waste - which can be reduced or eliminated. This activity is NOT the same as a work study exercise, but is able to represent the status of the process as a snapshot in time. This means that the exercise can be accomplished in a relatively short period of time. The primary benefit of a process mapping exercise is that it demands very close examination of the actual process, as it operates NOW - rather than how it might have been intended to operate, or how the management think it operates. The purpose is to create a clear and accurate understanding of the process - at a detailed level - and in a manner which makes the waste obvious. A by-product of the exercise is that it provides a detailed, accurate statement of the current performance of the process, in lean production terms - before any improvements are made. 4.1.13*Key Points

    This slide shows a typical process map, using the ASME symbols to illustrate all the process steps. This map would be the result of a very close study of the actual process as operated in the factory - not by studying written process instructions or by interviewing the process engineer or production manager. In the process map illustrated - only the green symbols add value - the rest is waste, which has now been made visible and can be attacked. Ask the audience to name each of the symbols. Of the 19 symbols in the map - only 5 are value add. It could be said that the Value Add Ratio of this process is 5/19 = 26% The total manual time is made up of both process activity at workstations and the manual movement of components between workstations. The WIP is made up of the 2 delays, 21 + 7, and 1 piece at each workstation (6) = 34 The manufacturing lead time is simply calculated by multiplying the total No of pieces of WIP by the takt time. 34 x 1.5 mins = 51 mins (this could also be an audience question) To make it easier to interpret any completed process map, and thus make it valuable, it is advisable to restrict the area under study to a manageable size. In the example shown, this is only a section of the whole process - but real improvements and genuine savings can still be made. 4.1.14*Key Points

    This slide shows a typical process mapping flow chart which captures - each element of the process- the process sequence- the ASME symbol- the process owner- a measure of the scale of the element- comments This chart enables us to identify all the process elements, their ASME category (whether they are waste or value add) and a measure of the scale of each element, e.g.- time for process- distance for transport- time or number of parts for delay- time for validation- number of parts for storage Having recorded all the process detail & identified the types of wastes within the process and the scale of those wastes, the task of re-designing the process to minimise those wastes can begin. 4.1.15*Key points The principles of lean production have been applied to all the areas of the process which were identified by the process map as WASTE.

    By re-designing the layout, much of the unnecessary movement of components is removed. Delays are also minimised.

    Each part is continuously processed one piece at a time and is fitted directly to the engine on the dress line. This reduces inventory (WIP) to 2 parts, 1 waiting in the delay and one being processed by the operator.

    By re-designing the layout to remove the wastes in the process, impressive gains can be made in terms of reduced inventory, reduced conveyance of materials and reduced processing time. (review the results table)

    Also by improving the layout we can reduce the non-added value activity of the operator, enabling additional added value activity to be carried out within a balanced assignment.4.1.16*Key PointsThis stage of Waste Elimination, Re-design the Process, needs to incorporate ALL the tools & techniques of Lean Manufacturing. All of the remaining content of the manual contributes to process re-design & the elimination of waste.This slide shows a simple form of process re-design - changing the layout of the process.By bringing the workstations close together and employing single piece flow there will be significant reductions in several of the wastes of the original process.Ask the audience to identify which wastes have been reduced in this layout.The answer is;- Inventory, since there are no longer bins of parts at each machine- Transport, since machines are now closer together & material is now moved 1 piece at a time from machine to machine.- Delay, since there are no bins of parts between machines, material now moves through the process with much less delay.- Scrap/rework, since the quantity of defect parts which could be in the system before detection is now much smaller (e.g.1 piece)4.1.17*Key points

    The U shaped cell is relatively compact and permits some waste reduction but there is a better way to support the introduction of the complete system.The parallel line cell allows takt-time working & any number of operators, between 1 & 6, to be efficiently employed in the cell to meet varying demand (and varying takt time).In the U cell, work combinations of; A & F or B & E include a large amount of wasted operator motion travelling between workstations - which is not the case with the parallel line cell.When process improvement produces reductions in cycle times - the parallel line layout allows work to be easily re-distributed around the cell to support real labour savings. Which wastes are further reduced this way?Answer; - Overproduction, since operators loaded to takt time cannot overproduce.- Overprocessing, since operators loaded to takt time do not have the time to overprocess.- Motion, (which initially increases in the U cell, to support reductions in the other wastes.) through closer positioning of machines & reduced return leg length. 4.1.18*Key points The next 2 stages in the process of waste elimination, Standarisation & Re-balancing are really part of the Lean Manufacturing tools Flexible Manpower System and Standardised Operations. They are included in the content of this presentation as they would need to be applied in the event of ongoing process improvement or genuine kaizen. This sheet provides the detail of the work that must be carried out when an operator arrives at the work station. It is vital that any revised and improved work routine or sequence is captured and standardised in this way - to help ensure consistency of process operation and to provide stability in preparation for the next improvement activity. Key points can be applied to cover issues such as,Quality.Safety.Knack - methods for productivity improvement. The complete set of documents used to record and standardise a process includes;- Standardised work chart- Standardised work combination table- Standardised work instruction sheet4.1.19*Whenever waste has been removed from a process, it will be necessary to review the operator workload balance.

    The slide shows a typical flexible manpower process, with 2 different standard work sequences.

    The sequence on the left shares the 110secs of manual work content equally between the 2 operators. This appears logical - but, it allows over-production (actual cycle time 55s, required cycle time (or takt time) 70s) and splits the waiting time into 2x15sec elements.

    The sequence on the right loads 1 operator to takt time (70s) and leaves the balance of 40s to the 2nd operator. This appears illogical - but with 1 operator loaded to takt, over-production is now impossible and the waiting time has been accumulated into 1x30s element which makes it more visible and more obvious to management as a target for improvement.

    Loading operators to the required cycle time or takt time also helps prevent over-processing, since the operator will not have the time within the assignment to do more than the standard work content. Key Points4.1.20*4.1.21