Module 4

Module 4MUDA, MURA, MURILEAN MANUFACTURINGLean 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.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 MANUFACTURING CONCEPTS 5S Kaizen Value Stream Mapping Quick Changeover/SMED JIT/Kanban Poka Yoke & Mistake Proofing Total Productive Maintenance

5 S HOUSKEEPING5 SJapaneseEnglish1 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 MAPPINGIt 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 customerSpecial type of flow chart that uses symbols known as "the language of Lean" to depict and improve the flow of inventory and information.

QUICK CHANGEOVER OR SMEDSMED efforts attempt to reduce the number of steps and the time it takes to perform each during a change in the manufacturing process.It provides a rapid and efficient way of converting a manufacturing process from running the current product to running the next product. This rapid changeover is key to reducing production lot sizes and thereby improving flow (Mura).

JITThe 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.

KANBANOne 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.

POKAYOKEPoka 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.

TOTAL PRODUCTIVE MAINTENANCETPM 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.JITJIT can be defined as an integrated set of activities designed to achieve high-volume production using minimal inventories (raw materials, work in process, and finished goods). JIT also involves the elimination of waste in production effort.

To ensure a good JIT system the following are essential:Reliable suppliersGood processes with least rejectionsBreak downs of equipment to be very lessContinuous flow of materials with no bottle necksLow set uptimes

BENEFITS OF JITCost SavingsRevenue increasesInvestment savingsWorkforce improvementsUncovering problems

WASTE MANAGEMENTWaste or muda is anything that does not have value or does not add value. Waste is something the customer will not pay for. Muda wasteful or unproductive activityMura - unevennessMuri overburden, unreasonableness

SEVEN TYPES OF WASTES1.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 defects

7 Types of WastesT TransportationE Excess productionA Added processesM MotionW WaitingI InventoryN Non-conformanceOverall Equipment Effectiveness (OEE)Overall Equipment Effectiveness (OEE) measures total performance by relating the availability of a process to its productivity and output quality.OEE was first used by Seiichi Nakajima, the founder of total productive maintenance (TPM), in describing a fundamental measure for tracking production performance. He challenged the complacent view of effectiveness by focusing not simply on keeping equipment running smoothly, but on creating a sense of joint responsibility between operators and maintenance workers to extend and optimize overall equipment performance.

OEE addresses all losses caused by the equipment, including

Not being available when needed because of breakdowns or set-up and adjustment lossesNot running at the optimum rate because of reduced speed or idling and minor stoppage losses Not producing first-pass A1 quality output because of defects and rework or start-up losses.

Overall Equipment EffectivenessTotal timee.g. 480 min. (1 shift)

Available timeRunning timeProductive timeEffective timeOEE is the way to measure how effectively machine / equipment hours are used (Value Adding)PlannedDowntimeDowntimePerformanceLossesQuality LossesOEE is lost due to:

- breakdowns, repairs- changeover- adjustment- start up- machine speed- short stoppages- lower yield- scrap- reject- rework- breaks, planned maintenance, trainingCalculation of LOSSESTotal time e.g. 480 min. (1 shift)Running time 340 min.Productive time270 min.Effective time250 min.PlannedDowntimeDowntimePerformanceLossesQuality Losses- breakdowns, repairs- changeover- adjustment- start up- long cycle time- minor stoppages- reduced yield- scrap- rework- rejects- breaks, planned maintenance, trainingTotal losses = 170 min / shiftAvailable time420 min.Calculation of OEEOEE takes into account all three OEE Factors, and is calculated as:

OEE = Availability x Performance Rate x Quality Rate(OEE = A x P x Q)Calculation of OEE Productive Performance=Running time - Performance loss Running time=340 min 70 min340 minQuality =Productive time - Quality loss time Productive time=270 min - 20 min270 minRunning Efficiency/Availability =Available time - DowntimeAvailability=420 min - 80 min420 min factor 81%factor 79.4% factor 92.6%XX= 59.6%OEE (in %) =Overall Equipment EffectivenessHow to increase OEE ?Data collection is the very important basis to increase OEECollect data for all downtimeand losses on the machineData analysis andvisible measureMake improvementsvisible and implementJFMAMJJASONDOEE TrendTarget 2003Analysis5101520253035RepairChangeoverTool changeScrapMinor Stopp.33261673RepairsChange over, Adjustm.Tool changeMinor stoppagesScrap, reworkAutonomous Mainten.Preventive MaintenanceChangeover reductionStandardize toolingImproved machinereliabilityStandardisationKaizen