GM INDIA POWERTRAIN PROJECT TRAINEE TOPIC SUMMARY Name of Trainee: SYAMLAL. A. R Qualification: Mechanical Engineering Institute: National Institute of Technology, Calicut Project Guide: Vinayak Angane Title of the project: SMED (Single Minute Exchange of Die), continuous improvement activity for crank changeover process. Brief Description of the project: Use SMED techniques to reduce changeover time through system for crank machining to throughput simulation approved levels. Activities to be performed by trainee: * Update crank changeover board to reflect the current. Create and manage tracking sheet of changeover issues and countermeasures. * Measure changeover times by operation. * Get changeover within ‘OEM’ specified timing by end of project. Learning/Expectation of the trainee at the end of term: * Understand process of manufacturing crankshaft. * Understand how to implement continuous improvement process on shop floor. * SMED research and implementation. ACKNOWLEDGEMENT I would like to express my gratitude to all the people in the General Motors Power Train department for helping me with my project.
I would like to thank the Human resources managers who gave me an opportunity to undertake such a project in a world renowned company as General Motors. I would also like to thank all the operators who passed on all the knowledge that they could in two months to help me understand all the processes. They also helped me in various situations where it seemed that my project would come to a standstill, giving me exactly what I needed to go on. Next I would like to thank the each and every single person in the crank line who helped me and guided me in every step.
They provided me with the resources and made suggestions that helped me improve and build a base for my ideas. I would also like to thank my fellow project trainee who had much more experience than me. He helped me to take off on my own path to completing the project with his valuable suggestion and ideas. Above all I would like to thank him for being a very good friend at the hour of need. I cannot fail to mention the undying support of Mr Kisan Kapse, Mr Prashant Kurde and Mr Bharat Sawant who helped me in every stage of the project. They were of great help in difficult times.
I am deeply in debt to them whose stimulating suggestions and encouragement helped me in times. Last but not the least I would like to thank my project guide Mr Vinayak Angane who looked closely throughout the project, correcting and offering suggestions for improvement. He took time off his busy schedule to explore me with alternate approaches to my problem and with ideas that could never have occurred to me on my own. INTRODUCTION The General Motors powertrain in Pune machines cam carrier, cylinder Head, cylinder block and crankshaft. GMI powertrain in Pune is a level IV flex plant.
This power train plant is the one and only Level IV Flex plant in India. A level IV flex plant means that the plant can machine different types of the same component in the same machine. This is done by changing the die holding the component and also changing the program mentioning where to machine. My project revolves around the SMED of crankshaft. Some different parts constitute of the Cylinder block, Cylinder head & the Crankshaft. The crankshaft is the part of an engine which translates reciprocatinglinearpiston motion into rotation.
Basically the crankshaft powers the engine. Crankshafts can be monolithic (made in a single piece) or assembled from several pieces. Monolithic crankshafts are most common, but some smaller and larger engines use assembled crankshafts. The different types of crank made in GM Powertrain Talegeon plant are 1. 0 xSDE, 1. 2 BDOHC, 1. 3 xSDE and 1. 4 BDOHC. SMED (Single Minute Exchange of Die) is a method for rapidly and efficiently converting a process from running the current product to running the next product. SMED is also often referred to a Quick Changeover.
The SMED method can, and often is, used in starting up a process and rapidly getting it to running condition with minimum waste of time. SETUP CHANGE / CHANGEOVER Setup change/ Changeover is preparation, execution of activities in work station which includes hardware changes, sometimes software changes e. g. : locator centres, chuck jaws, steady program calling etc. to produce good to good parts. Change over time is defined as the time difference of the last product produced and the next new product produced with the right quality and at the right speed. The production capacity of a plant is determined by the changeover time.
Unless the changeover time is reduced to the bottleneck the production can’t meet the target Production sites with long setup times are characterised by * Low flexibility of the component * Large batch sizes * High levels of stock If we decrease the setup change time then we could use the extra capacity either to increase productivity or to decrease the batch sizes. There are many benefits likereduction in lead time and therefore increased, improved and faster delivery, higher productivity and therefore satisfying customer needs faster, Reduction in working capital, less disturbances etc.
SINGLE MINUITE EXCHANGE OF DIE (SMED) The process of changing die is called Single Minute Die Exchange (SMED). Single-Minute Exchange of Die (SMED) is one of the many lean production methods for reducing waste in a 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 the key to reducing production lot sizes and thereby improving flow. The phrase “single minute” does not mean that all changeovers and start-ups should take only one minute, but that they should take less than 10 minutes.
In short it should be a single digit number. The different features of SMED are: * It is a systematic approach that decreases disturbances and problems * The main factor that can lead to its success are team work & creativity * SMED methods are used for exchange of dies, but it can also be used for cleaning and for maintenance purposes. IMPORTANCE OF REDUCING CHANGEOVER TIME Reducing changeover time is like adding capacity, increasing profitability and can help most manufacturers gain a competitive edge.
Image a pit crew changing the tires on a race car. Team members pride themselves on reducing changeover by even tenths of a second because it means that their driver is on the road faster and in a better position to win. The same philosophy applies to manufacturing – the quicker you are producing the next scheduled product, the more competitive you are. Reducing changeover times is a fundamental requirement of any company to take lead over the other in production and maintaining top position.
By understanding the principles and practices of the SMED system organisations will be able to cut changeovers by over 50% with very little expenditure, and to single minutes with the modification of tooling and fastening systems. Single Minute Exchange of Dies can be applied to any changeover operation and aims to reduce the overall downtime for a complete changeover to less than nine minutes. An understanding of the operational benefits to be gained from the fast exchange of tooling. The interaction of a multi-disciplined workforce constructively looking to eliminate waste from the changeover process.
How unstable setups can adversely affect subsequent operations and how standard operating procedure can eliminate these concerns. A team approach in understanding the methodology used in applying SMED through theoretical explanation and practical involvement in actual changeovers. SMED IMPLEMENTATION To successfully implement SMED in a system is a difficult task. Therefore to successfully guarantee the implementation of the process, the following steps should be followed closely. STEP 1 – FOCUS * Start by choosing the right equipment to start with. . This is normally a bottle-neck with long set-up times STEP 2 – BUILD THE RIGHT TEAM Work cross-functional. Operators, Technicians, Engineers and Managers should worktogether STEP 3 – MEASURE AND SET GOALS * Visualize the present situation and agree on a common goal STEP 4 – 5S * To succeed you will need a clean and well organized work-place. A 5S implementation is recommended. This process will be explained in detail as we move ahead. STEP 5 – ANALYSIS * Keenly observe the operations and processes. Analyze the present situation video-technique. The different moments are classified as being external or internal and waste or not waste. All known disturbances are listed as well.
STEP 6 – SEPARATION BETWEEN INTERNAL AND EXTERNAL MOMENTS * The purpose is to secure that all external set-ups are performed when the machine is running. Use checklists, function controls and improved transports. For example collect necessary tools and consumables before the next operation starts up or sharp the tools before activity starts. STEP 7 – ELIMINATION OF WASTE * Measures are carried out to reduce all types of waste. This includes: * Elimination of all need for adjustments. * Exchange of bolts for quick-fasteners. * Standardized parts, tools, dimensions Need for quality control STEP 8 – FOLLOW UP AND IMPROVE * Each changeover should be so planned that it is better and faster than the previous one. Each changeover should be analysed and properly documented which includes suggestion that could make it faster THE 5S SYSTEM “5S” is a method to create a safer, cleaner, and better-organized workplace. The five S in the process stand for: * SET IN ORDER The principle here is to keep things in their proper places. One guide to proper placement is to keep frequently-used items handy, and store other things where they can be found.
In reference to a workplace, it means: At present the tools required for the changeover process are stored in red tool carts and the carts are kept in a specific location for easy access. The tool carts are rolled to the machine where changeover is taking place at the required time. SORT Every tool which is used for a changeover process must be tagged and identified properly. All the operators involved in the changeover must be aware of the location and purpose of the tool. SHINY CLEAN This is the exception – the only one-time activity in the 5S method. This stage has two goals: Determine and gain agreement on the desired level of cleanliness * Learn how to make new routines so this will become standardized STANDARDIZED CLEANUP In this phase consider the sources of dirt: air-borne dust; sawdust or other dry powder from cutting operations; splatter from wet processes; or simple trash because there is no proper container. A practical target is to have all workers take five minutes every day to tidy up after themselves – including the time to complete and sign the checklists. Supervisors should monitor compliance with the clean-up. The checklists make this both important and achievable.
SUSTAIN This phase is perhaps the most important concept that includes instilled discipline, self-discipline, common cultural values, and self-motivated practice to improve. This step requires continued management support and communication. It brings out the leadership qualities of the employees and also improves their human values too. All these activities should be followed up on a regular basis with full commitment and hard work from all operators as well as managers for SMED to be a success. ACTIVITIES PERFORMED * Understood process of manufacturing crankshaft
Understood the process of manufacturing crankshaft with the process flow of current status and different machines involved. * Understood activities performed by different machines OP 10:Machine: HELLER * Mill the lengths * Centring * Orbital and hollow milling OP 20:Machine: HELLER * Rough milling of mains/pins incl. * Counter weights and incl. * Rough diameter of mains and pins OP 25:Machine: HELLER * Broaching of mains and journals OP 30:Machine: HELLER * Outer Diameter milling of pins OP 40 (A & B):Machine: NTC * Drill and camphor oil holes OP 50:Machine: ELOTHERM * Washing Hardening (only for xSDE) * Tempering (only for xSDE) OP 60:Machine: HEGENSCHIEDL * Deep rolling * Strengthening OP 70:Machine: NTC * Recenter both ends OP 80:Machine: NILES-SIMMONS * Finish turning * Thrust face and hub outer diameter and post end shoulder * Post process measuring OP 100 (A & B):Machine: LANDIS * Grinding mains and pins OP 110 (A & B):Machine: NTC * Ream index holes * Milling keyway * Machine reluctor ring holes and flange holes OP 120:Machine: ROBOTIC * Brush * Check oil holes OP 140:Machine: LANDIS * Grinding Flange and post ends OP 160:Machine: SCHENK BALANCE Balancing OP 170:Machine: SUP FINA * Polish mains and pins * Thrust face and flange outer diameter (2 stations) OP 180:Machine: FINE TEC * Wash and dry OP 190:Machine: HOMMEL * Final inspection (2 stations) OP 200:Machine: MANUAL * Manual assembly of dowel pin SMED FOR CRANKSHAFT CHANGEOVER My project revolves around the changeover process in the crankshaft line. My project activities can be divided into the following: * Documentation of the changeover process for the entire crankshaft line. * Identified and separated internal and external activities for the changeover process. To define separate activities for different operators. My activity here consists of reducing changeover time. TO REDUCE CHANGEOVER TIME USING SMED TECHNIQUES The steps involved in reducing the changeover tie using this method are: 1. Observe the current methodology 2. Document it appropriately 3. Separate the INTERNAL and EXTERNAL activities. Internal activities are those that can only be performed when the process is stopped, while External activities can be done while the last batch is being produced, or once the next batch has started.
Make sure it is properly documented. 4. Do most of the activities to be done during the changeover to be done when the previous batch is being done or while the buffer is running. 5. Try to simplify each and every process. 6. The procedure as well as the measures taken to simplify the timings should be well documented and easily accessible. 7. Keep a standard improvement percentage for each new changeover. Teamwork, meaning several operators sharing changeover operations in order to minimize the stop time is also scarce.
As changeovers take time, cause productivity loss and carry costs, the temptation is to dilute them in changing less often by launching bigger batches. This policy ends up with higher inventories and lower agility for the production. Documented the current changeover process The machine is usually stopped and all changeover operations happen in sequence, while the machine is stopped. The machine will start again only after completion of adjustments and trials. Most often all these operations are done without any standard method nor procedures or checklists.
This means the changeover sequence, and hence its duration is related to individual know-how, skills and habits. During this stage: * Agreed on the start and end of the changeover * Observed the changeover * Recorded ALL observations * Organized it and created changeover table * Record times for each element The time required for each individual steps were measured and added to the table for OP 20, OP 25, OP 30 and OP 40. Recorded and organized all observations for OP 20, OP 25, OP 30, OP 40, OP 60, OP 70, OP 80, OP 100 and OP 160 and created a table as follows:
Separated INTERNAL and EXTERNAL activities Another important process is separating the internal and external activities performed during changeover. This is a serious procedure which must be done with a lot of care, which will help in the reduction of changeover time. During this stage: * Identified whether each step in the changeover is ‘internal’ or ‘external’ * INTERNAL activities are those which can be performed only when the machine is stopped (e. g. : removing or clamping jaws) * EXTERNAL activities are those which can occur while the machine is running (e. g. returning tools to storage after use and bringing new tools to the machine) * Separated each step involved in changeover to internal and external Separated activities for OP 20, OP 25, OP 30, OP 40, OP 60, OP 70, OP 80, OP 100 and OP 160 and added in the same table. Different external activities consist of: * Having everything prepared before stopping the machine (checklists) * Any preheating, pre-cleaning, presetting that could be completed * Standardizing changeover parts with attachments/improvements to help speed up centering and securing * Cleaning and keeping new changeover parts to be changed
Defined activities for both team members During the next phase of the project, I defined activities for both the team members involved in the changeover, i. e. the steps that must be performed by first operator and second operator were classified. The thought of parallel operations leads mainly to the following features: * Two or more people doing different jobs at the same time (e. g. : while first operator removing tool, second one bringing tool trolley in position in case of OP 20) Two people working together on one operation (e. g. : Both the operators changing over OP 40 A and OP 40 B simultaneously Others * Recorded the different tools and the auxillary equipments required to complete the changeeover * The different tools used in every step of changeover were noted down. * Bolt size of different allen screws were recorded * Auxillary equipments needed such as torque wrench, ratchet etc. were added in the same tabe * Organized changeover parts in the part trolley
As part of the implementation of 5S system, inorder to reduce the part searching time, each and every part involved in the changeover process were photographed. These photos were stick inside the machine tool trolley and hence the part searching time was reduced. * Improving location labeling to make items easier to find * Organized changeover parts in part trolley with photos having part number and part name on them * Hence reducing the time required for accessing the correct part * Deskilling and avoiding confusion SAMPLE PICTURE * The photographs were stick inside the tool trolley For different models, differents racks were provided so as to avoid confusion * In one rack, the space wasseparated inorder to fit to all the parts to be changed over All the above processes helped in reducing the part searching time and also worked as an alternate checklist. Also created a chelist of different parts to be changed for different operations. * Measured changeover time by station * Plotted graph with comparison of actual time taken by station for changeover to simulation * Plotted graph for total time taken for changeover for OP 20 to OP 180 Plotted graph for time taken to changeover from model 1. 0 to 1. 2 for OP 20 to OP 180 * Plotted graph for time taken to changeover from model 1. 0 to 1. 2 for OP 20 to OP 180 Suggestions * Providing power tool for all loosening and tightening processes instead of Allen key * Power tool will reduce about: 15 min for OP 20 3 min for OP 25 9 min for OP 30 * OP 40 * Changeover both OP 40 A and OP 40 B simultaneously * Reduce machine lockout time by making bed flush valve in action which was not noticed earlier * Hence solved problem of chips getting stuck in burr OP 60 * Get power tool * Change the tool tray (boxes) in which rollers are placed * Arrange rollers in boxes in same order that they are to be used * Stick colour codes on box also * Make arrangement loosen minimum number of bolts and adjust measuring probe * Provide power tool for OP 80 will reduce approximately 4 min * OP 160 * Provide a plastic kit (box) with separations which can be taken and placed inside the machine through the side door which makes the operator not to lean in and out of machine each and every time * Bearing seal on the extreme is not used for 1. xSDE which is not required to be mounted * OP 10, OP 50, OP 70, OP 100, OP 110, OP 120 and OP 180 are already changed over in time or about time CONCLUSION At the end of the project, I was able to understand process of manufacturing crankshaft, different machines used in crank line and their uses, what is changeover and its use in the plant, advantages and disadvantages of changeover and importance of reducing changeover time. As a preliminary step to the project, I studied the basic idea of SMED (Single Minute Exchange of Die) and 5S techniques.
Found out how SMED techniques can be used to reduce changeover time. During the project, I documented the whole process step by step for changeover for OP 20, OP 25, OP 30, OP 40, OP 60, OP 70, OP 80, OP 100 and OP 160. Organized these steps and created a changeover procedure table. Defined activities for both the team members involved in the changeover in the same table. Separated internal and external activities occurring during changeover and marked it in the changeover procedure table. Time taken for each step in the same table was also recorded (for OP 20, OP 25, OP 30 and OP 40).
Reduced machine lockout time for OP 40 by making bed flush valve in action which was not noticed earlier and hence solved the problem of chips getting stuck in the burr and making the cleaning process long and difficult. The changeover parts in the part trolley were organized with the help of photos having part number and part name. Measured changeover time by station and plotted graphs: * Comparison of actual time taken by station for changeover with simulation time (For OP 20 to OP 180 for last 7 changeovers) * Total time taken for changeover by stations For OP 20 to OP 180 for last 7 changeovers) * Time taken for changing over from 1. 0 xSDE to 1. 2 BDOHC (For OP 20 to OP 180 for last 4 changeovers) * Time taken for changing over from 1. 2 BDOHC to 1. 0 xSDE (For OP 20 to OP 180 for last 5 changeovers) Updated crank changeover board to reflect current by updating different graphs required and action plan. The process to implement continuous improvement on shop floor was understood and perfected. Different steps to decrease the time taken for changeover process and to bring it under OEM specified timing was suggested.