PTTQM (BU-3)Module 4MODULE 4MUDA, MURA, MURI1. What is lean? Lean is a philosophy that seeks to eliminate waste in all aspects of a firms production activities: human relations, vendor relations, technology, and the management of materials and inventory. Lean is principally associated with manufacturing industries but can be also equally applicable to both service and administration processes.2. What is the primary goal of any lean system?The elimination of waste is the primary goal of any lean system. In effect, lean declares war on waste any waste. We should eliminate all forms of wastes in any process or product until only what is valuable remains. The key is to spot waste and then stop waste.

3. Explain the concept of lean manufacturing. Lean Manufacturing is a systematic methodology that identifies and eliminates all types of waste or non-value-added activities; not only in production or manufacturing operations, but in the service industry as well. Whether you are manufacturing a product or providing a service, there are components that are considered waste. Lean concepts are purely about creating more value for customers by eliminating activities that are considered waste. Any activity or process that consumes resources, adds cost or time without creating value becomes the target for elimination. Lean focuses on the big picture or improvements in the entire business process as opposed to incremental improvements. It is the business process system that can significantly improve a companys profitability.Lean concepts improve operating performance by focusing on the continuous flow of products, materials or services through the value stream. To achieve this, the various forms of waste must be identified and eliminated. Waste can include any activity, step or process that does not add value for the customer. Lean Manufacturing, sometimes also referred to as the Toyota Production System, is about the systematic elimination of waste.

LEAN Manufacturing Concepts 5S Kaizen Value Stream Mapping Quick Changeover/SMED JIT/Kanban Poka Yoke & Mistake Profing Total Productive Maintenance

5SThe basis for good housekeeping in Japanese companies is a concept popularly known as 5S. This stands for five good housekeeping concepts in Japanese.5 SJapaneseEnglish

1 SSeiriSort out unnecessary items in the workplace and discard them.

2 SSeitonArrange necessary items in good order.

3 SSeisoClean your workplace thoroughly so that there is no dust on floors, machines and equipment.

4 SSeiketsuMaintain high standards of housekeeping at workplace at all times.

5 SShitsukeTrain people to follow good housekeeping disciplines.

Kaizen "Kai" means change, and "Zen" means good (for the better). Basically kaizen is for small improvements, but carried out on a continual basis and involve all people in the organization. Kaizen is opposite to big spectacular innovations. Kaizen requires no or little investment. The principle behind is that "a very large number of small improvements are more effective in an organizational environment than a few improvements of large value.

Value stream mapping It is often part of a kaizen event. In its true form the value stream map documents all parts of the manufacturing process from the time the order is taken until it is delivered to the customer

Quick Changeover or SMED (Single Minute Exchange of Dies) SMED efforts attempt to reduce the number of steps and the time it takes to perform each during a change in the manufacturing process.

JIT/KanbanThe concept originated in Japan and adopted by many companies in India. As a concept, JIT means materials arrive on time and no inventories are held at any time either in raw materials, WIP or finished goods. Materials are pulled in to the system. JIT system ensures great efficiency in production. Monden (1981) defines JIT as a production system to produce the kind of units, at the time needed and in the quantities needed.One of the most important tools in a pull system is kanban. Based on a proven Japanese model, kanban is a visual approach to production control, using simple tools like returnable containers, cards, or even empty spaces to pull products from producing workstations or suppliers toward consuming workstations or businesses. In this context, a kanban is a sign or visual aid indicating that a work center has finished a process, requires work, or needs more materials. Kanban enable work centers to track supplier or customer needs and respond quickly and appropriately.

Pokayoke and mistake proofingPoka Yoke is a quality management concept developed by a Matsushita manufacturing engineer named Shigeo Shingo to prevent human errors from occurring in the production line. Poka yoke (pronounced poh-kah yoh-kay) comes from two Japanese words yokeru which means to avoid, and poka which means inadvertent errors. Thus, poka yoke more or less translates to avoiding inadvertent errors. The main objective of poke yoke is to achieve zero defects. In fact, it is just one of the many components of Shingos Zero Quality Control (ZQC) system, the goal of which is to eliminate defective products.A quality concept to manufacture ZERO defects & elimination of waste associated with defects is known as zero defect quality. The goal of ZDQ is zero! Make certain that the required conditions are in place and controlled to make acceptable product 100% of the time. ZDQ functions by combining four elementary components:1. Point of Origin Inspection2. 100 % Audit Checks3. Immediate Feedback4. Poka-YokeTotal Productive Maintenance (TPM) TPM is a support function promoting high machine time availability and effectiveness. As companies increase the use of LEAN techniques wasted steps are eliminated in the manufacturing process to provide more time processing material and making products customers want.

4. What is OEE?Overall Equipment Effectiveness (OEE) measures total performance by relating the availability of a process to its productivity and output quality.OEE addresses all losses caused by the equipment, including1. Not being available when needed because of breakdowns or set-up and adjustment losses2. Not running at the optimum rate because of reduced speed or idling and minor stoppage losses 3. Not producing first-pass A1 quality output because of defects and rework or start-up losses. 5. Calculate OEE for the following data:The table below contains hypothetical shift data, to be used for a complete OEE calculation, starting with the calculation of the OEE Factors of Availability, Performance, and Quality. Note that the same units of measurement (in this case minutes and pieces) are consistently used throughout the calculations.ItemData

Shift Length8 hours = 480 min.

Short Breaks2 @ 15 min. = 30 min.

Meal Break1 @ 30 min. = 30 min.

Down Time47 minutes

Ideal Run Rate60 pieces per minute

Total Pieces19,271 pieces

Reject Pieces423 pieces

SOLUTION: Planned Production Time= Shift Length - Breaks

= 480 - 60

= 420 minutes

Operating Time= Planned Production Time - Down Time

= 420 47

= 373 minutes

Good Pieces= Total Pieces - Reject Pieces

= 19,271 423

= 18,848 pieces

Availability= Operating Time / Planned Production Time

= 373 minutes / 420 minutes

= 0.8881 or 88.81%

Performance= (Total Pieces / Operating Time) / Ideal Run Rate

= (19,271 pieces / 373 minutes) / 60 pieces per minute

= 0.8611 or 86.11%

Quality= Good Pieces / Total Pieces

= 18,848 / 19,271 pieces

= 0.9780 or 97.80%

OEE= Availability x Performance x Quality

= 0.8881 x 0.8611 x 0.9780

= 0.7479 or 74.79%

6. Calculate OEE for the following:

A machine has been planned to work for 3 shifts of 8 hours each. Due to problems w.r.t power etc it was idle for 129 minutes. The job running on the M/C was supposed to take 3 mts/piece. The actual pieces produced were 403 out of which 17 pieces are not accepted.

Solution:OEE = Quality x Performance x Availability

Availability = operating time / planned production time = (3x8x60-129) / 3x8x60 = 0.91Quality = good pieces / total product = 403-17/403 = 0.96Performance = [cycle time x total product] / operating time = 3x403 / 1311 = 0.92Overall Equipment Efficiency [OEE] = 0.96 x 0.92 x 0.91 = 0.8037 = 80.37%7. Calculate OEE for the following data:(Jan 2007)a) Hrs/day: 16b) M/c idle / day: 2 hrsc) No. of pieces/hr. expected: 20d) Actual pieces produced: 240e) No. of pieces rejected: 20Solution:OEE = Quality x Performance x AvailabilityAvailability = operating time / planned production time = (16-2) / 16 = 0.875Quality = good pieces / total product = 240-20/240 = 0.9167Performance= (Total Pieces / Operating Time) / Ideal Run Rate

= (240 pieces / 14) / 20 pieces per hr. = 0.8571

Overall Equipment Efficiency [OEE] = 0.875 x 0.9167 x 0.8571 = 0.6875 = 68.75%

8. Find the OEE for the following: A machine works 16 hours/day and it was idle for 2 hours in a day. In the actual hours worked they are able to produce 360 pieces for a job which requires 2 minutes/piece. Even in the 360 pieces there were 20 pieces rejected.Solution:OEE = Quality x Performance x AvailabilityAvailability = operating time / planned production time = (16-2) / 16 = 0.875Quality = good pieces / total product = 360-20/360 = 0.944Performance = [cycle time x total product] / operating time = 2/60x360 / 14 = 0.8571Overall Equipment Efficiency [OEE] = 0.875 x 0.944 x 0.8571 = 0.7080 = 70.8%

9. What is Gemba kaizen?"Kai" means change, and "Zen" means good (for the better). Basically kaizen is for small improvements, but carried out on a continual basis and involve all people in the organization. Kaizen is opposite to big spectacular innovations. Kaizen requires no or little investment. The principle behind is that "a very large number of small improvements are more effective in an organizational environment than a few improvements of large value. 10. What are the features and benefits of kaizen?Features of Kaizen Widely applicable Can be used in both manufacturing and non-manufacturing environments Highly effective & results oriented. Kaizen events will generate quick results, Measurable results, establish the baseline, and measure the change!!! A Learning Experience Every member of a Kaizen Team will walk away from the event learning something new! Team based & cross functional Team members can be from various functions of the business. Top management participation is encouraged. Benefits of Kaizen Kaizen Reduces Waste- like inventory waste, time waste, workers motion Kaizen Improves space utilization, product quality Results in higher employee morale and job satisfaction, and lower turn-over. Toyota is well-known as one of the leaders in using Kaizen. In 1999 at one U.S. plant, 7,000 Toyota employees submitted over 75,000 suggestions, of which 99% were implemented.

11. What is TPM? How does it differ from other maintenance systems? What are the salient features of TPM? Total Productive Maintenance (TPM) is a maintenance program which involves a newly defined concept for maintaining plants and equipment. The goal of the TPM program is to markedly increase production while, at the same time, increasing employee morale and job satisfaction. TPM brings maintenance into focus as a necessary and vitally important part of the business. It is no longer regarded as a non-profit activity. Down time for maintenance is scheduled as a part of the manufacturing day and, in some cases, as an integral part of the manufacturing process. The goal is to hold emergency and unscheduled maintenance to a minimum. The major difference between TPM and other concepts is that the operators are also made to involve in the maintenance process. The concept of "I (Production operators) Operate, You (Maintenance department) fix" is not followed.

Salient features of TPM TPM is not a specific maintenance policy; it is a culture, a philosophy and a new attitude towards maintenance. TPM is the involvement of operators in carrying out autonomous maintenance by participating in cleaning, lubrication, minor repair, adjustments etc. TPM gives both the productivity index at the aggregated organization level as well as at the detailed operational unit level. It also gives the individual productivity indices for the individual parts. It indicates the profitability of individual operational unit as well as the overall organization, thereby giving indication as to which units operation to continue and all its future investment decisions. At the same time, it clearly indicates which units is a liability and when to get out of these units. TPM determines the profitability of individual products and the correct product mix to optimize the profit as well as optimum utilization of resources. It provides important and vital information for strategic planning TPM shows which particular input resources are utilized inefficiently in a particular area or for a particular product so that its efficient and effective use can be ensured. TPM integrates the entire work of planning, execution, evaluation and improvement phases in the productivity cycle of an organization. TPM has developed individual and collective mathematical models for the productivity indices calculation. This makes the model validation and sensitivity analysis relatively easier and precise.

12. What are the aims of TPM? How is TPM implemented in manufacturing organisations? What are the benefits of TPM?Total Productive Maintenance (TPM) is a maintenance program which involves a newly defined concept for maintaining plants and equipment. The goal of the TPM program is to markedly increase production while, at the same time, increasing employee morale and job satisfaction. TPM brings maintenance into focus as a necessary and vitally important part of the business. It is no longer regarded as a non-profit activity. Down time for maintenance is scheduled as a part of the manufacturing day and, in some cases, as an integral part of the manufacturing process. The goal is to hold emergency and unscheduled maintenance to a minimum. TPM was introduced to achieve the following objectives. The important ones are listed below. Avoid wastage in a quickly changing economic environment. Producing goods without reducing product quality. Reduce cost. Produce a low batch quantity at the earliest possible time. Goods send to the customers must be non defective.Steps in TPM Implementation in manufacturing organizationStep 1 - PREPARATORY STAGE: Announcement by Management to all about TPM introduction in the organization:Proper understanding, commitment and active involvement of the top management in needed for this step. Senior management should have awareness programmes, after which announcement is made to all. Publish it in the house magazine and put it in the notice board. Send a letter to all concerned individuals if required. Initial education and propaganda for TPM:Training is to be done based on the need. Some need intensive training and some just an awareness. Take people who matters to places where TPM already successfully implemented. Setting up TPM and departmental committees:TPM includes improvement, autonomous maintenance, quality maintenance etc., as part of it. When committees are set up it should take care of all those needs. Establishing the TPM working system and target:Now each area is benchmarked and fix up a target for achievement. A master plan for institutionalizing:Next step is implementation leading to institutionalizing wherein TPM becomes an organizational culture. Achieving PM award is the proof of reaching a satisfactory level. STEP 2 - INTRODUCTION STAGEThis is a ceremony and we should invite all. Suppliers as they should know that we want quality supply from them. Related companies and affiliated companies who can be our customers, sisters concerns etc. Some may learn from us and some can help us and customers will get the communication from us that we care for quality output. STAGE 3 - IMPLEMENTATIONIn this stage eight activities are carried which are called eight pillars in the development of TPM activity. Of these four activities are for establishing the system for production efficiency, one for initial control system of new products and equipment, one for improving the efficiency of administration and are for control of safety, sanitation as working environment. STAGE 4 - INSTITUTIONALISING STAGEBy all their activities one would has reached maturity stage. Now is the time for applying for PM award. Also think of challenging level to which you can take this movement. Direct benefits of TPM1. Increase productivity and OPE (Overall Plant Efficiency) by 1.5 or 2 times.2. Rectify customer complaints.3. Reduce the manufacturing cost by 30%.4. Satisfy the customers needs by 100 % (Delivering the right quantity at the right time, in the required quality )5. Reduce accidents.6. Follow pollution control measures.Indirect benefits of TPM1. Higher confidence level among the employees.2. Keep the work place clean, neat and attractive.3. Favorable change in the attitude of the operators.4. Achieve goals by working as team.5. Horizontal deployment of a new concept in all areas of the organization.6. Share knowledge and experience.13. Write the steps of waste elimination.The steps to effective waste elimination are: Make waste visible. Be conscious of the waste. Be accountable for the waste. Measure the waste. Eliminate or reduce the wasteIn other words, before one can stop waste, he should able to see it, recognize it as waste, identify who is responsible, and finally appreciate its size and magnitude. Waste that is not seen cannot be eliminated. When one refuses to accept responsibility for the waste, then he will not eliminate it. Finally, when the waste is not measured, people may think it is small or trivial and therefore will not be motivated to stop it. As the saying goes What is not measured, is not improved.

14. Why do organizations want to use lean manufacturing techniques?The organizations use lean manufacturing techniques in order To significantly improve overall productivity To increase market share To improve speed-to-market with new products To reduce manufacturing and engineering labor costs To eliminate non-value-added operations and processes

15. What is Muri and Muda? Muda = waste (in its many forms). Muda waste is often accompanied or caused by...Mura = unevenness, overburden, strainMuri = demand that exceeds process and equipment capacities.16. What is waste management? Discuss the seven wastes. Waste or muda is anything that does not have value or does not add value. Waste is something the customer will not pay for.

The seven types of waste are:1. Waste from overproduction2. Waste from waiting times3. Waste from transportation and handling4. Waste related to useless and excess inventories5. Waste in production process6. Useless motions7. Waste from scrap and defectsWaste from overproductionIt may sound surprising, but many companies are producing more than necessary because they lose parts, products, material! Without order, care and discipline in storage, inventories will fill all available space. Temporary storing a batch in a non defined / dedicated area is risky, as someone could move the batch without care or notice. In such a case, it is likely to lose its track, all ending in a waste of raw material, energy and man power.It may lead to a double waste if the lost batch requires to produce a new one be delivered! Eliminating the wasted space and valuable surface by excess inventories and overproduction is another potential improvement.Waste from waiting timesWaiting is a consequence of poor synchronization between process stages or bad preparation. Waiting for parts, material, tools, instructions, etc, can be caused by a lack of rules about storage places, when people have to search everywhere.Are the items you are waiting for really necessary? If they're not, if they do not add value to the job or the product, it it wise to try to eliminate them or at least reduce the wait time and storage distances.Waste from transportation and handlingThe necessity to move and transport can be caused by the previously mentioned wastes. All transportations may not be eliminated, but they have to be kept to the very minimum.Looking for a pallet truck to move crates or pallets is a common occupation in the workshops. People most often claim for more trucks, but a proper set of rules, parking areas and discipline to bring them back after use is enough to solve availability problems.Waste related to useless and excess inventories "Useless"! The name itself gives the solution. In the 5S way, anything that is useless is to be eliminated. In case of inventories, the gain is the value of the goods stored and the regained spaces, which must be dedicated preferably to value creating activities.Paper documents and their numerous copies, catalogues and calendars of previous years, files and data, dry and worn out pens and pencils... all excess inventories!Waste in production processProcedures and work guides which are not constantly updated are likely to let useless operations be performed in the process. Sorting and ordering applies also in the sequences of the process and the related documents. This type of waste is also common in administration processes and office work. Old rules still remain even if the causes of their creation disappeared a while ago. As long as nobody will update the set of rules, everyone will carry on, sticking to the olds with application and discipline (!!).Useless motionsErgonomics of the work place is certainly the most popular and "visible" application of the 5S. The layout and display of the area will follow the 5S logic, favoring availability of necessary items, distance of reach, and ease for tending...Among useless motions, do not forget the walks to search for missing items, data, instructions, complementary information...Waste from scrap and defectsNumber of defects and quality problems can be directly linked to the work place state: Assembly mistakes (parts mismatch) due to jammed work table with parts from different models / series Forgotten parts in assembly, the parts could not be seen in the mess on the table Scratches on parts by scrap form the work table (burrs, dirt, parts...) Spoiled parts, useless because dirty, scratched... Assembly mistake by not following the right sequenceWe can remember the seven wastes using the acronym TEAMWINT TransportationE Excess productionA Added processesM MotionW WaitingI InventoryN Non-conformance

17. What is the use of MURA and MURI?MURA, unevenness, can be found in fluctuation in customer demand, process times per product or variation of cycle times for different operators. In production environments with low-volume, high product variation, flexibility is more important than in high-volume, low-product variation environments. When Mura is not reduced, one increases the possibility for Muri and therefore Muda. Mura can be reduced by creating openness in the supply chain, change product design and create standard work for all operators. MURI, overburden, can result from Mura, and from removing too much Muda(waste) from the process. When operators or machines are utilized for more than 100% to finish their task, they are overburdened. This meansbreakdownswhen it comes to machines and absenteeism when it comes to employees. To optimize the use of machines and make sure they function properly, preventative- and autonomousmaintenance can be implemented. To prevent overworked employees, safety should be the focus of all process designs and all standard work initiatives.

Prof. Raghavendra, KSM, BangalorePage | 6