5S METHOD IN LEAN MANUFACTURING

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1 5S METHOD IN LEAN MANUFACTURING Professor Virgil POPA Ph D Master degree student Alina BIDIREANU Master degree student Mihai TOADER Valahia University of Targoviste virgilp51@yahoo.com Abstract LEAN MANUFACTURING is the production system the produces more with less, being known also as supple production or no loss production, which means minimum COSTS production. Lean Manufacturing is thinking and an involvement way for the complete elimination of losses, oriented to the customers success, possible to obtain through the simplification and the permanent improvement of all the processes and the relations in a climate of mutual trust, respect and full implication of the employees. Added value: Any activity that increases the value or the utility of the product or service requested by the market, namely the activities for which a customer is willing to pay. Loss (Non -added value): Any activity which don t add value to the product or service, meaning what raises the COST of the product without adding VALUE for the customer. The 5S method include 5 phase: 1. SEIRI Sorting and Filtering Sorting is a method of freeing de space at the workplace and the elimination of all the unnecessary objects, like programs, test pieces, drawings, old or defective tools, accessories, unused materials, etc. The sorting process has an impact on the mentality at the workplace and removes the syndrome it works like this. 2. SEITON Stabilization (Systematization of objects location) Stabilization means setting the locations (boundaries). The second step of 5S refers to arranging in order the useful objects at the workplace, so these can be easily find/identified and in a logical order to facilitate their use. 3. SEISO Shining (Shining and cleanliness) Shining means initial cleanliness and the cleanliness of everything represents the workplace: floor, machines, cabinets, etc. It s imperative to detect the sources of dirt, the sources of leakage must be corrected and it must be provided enough material to perform cleaning at any workplace. This is the only way to improve the products quality and the people s safety. 4. SEIKETSU Standardization Standardization means maintaining the status obtained by setting rules, habits and standard procedures. Standardized work is obtained by finding the best working method from different people, on the same machine or workbench; using the standard equipment as recipients, various color files, etc.; displaying standard procedures on panels (visual management); using check lists. 5. SHITSUKE Support for change

2 Support for change always requires that specific procedures be followed (and standardized). Keywords: Lean Manufacturing, 5S, Added value, Loss, Seiri, Seiton, Seiso, Seiketsu, Shitsuke JEL Classification: L600 Introduction LEAN MANUFACTURING is the production system the produces more with less, being known also as supple production or no loss production, which means minimum COSTS production. Lean Manufacturing is a production philosophy which determines the reducing of time since the customer order to the product delivery, continuously minimizing the losses. There are many definitions, such: - Lean manufacturing is a production philosophy that reduces the time elapsed from the customer order to the product delivery, through reducing the losses (the activities that don t add value to the product) [J. Womack & D.T. Jones, 1990] - Lean Manufacturing is a thinking and an involvement way for the complete elimination of losses, oriented to the customers success, possible to obtain through the simplification and the permanent improvement of all the processes and the relations in a climate of mutual trust, respect and full implication of the employees [J. Womack & D.T. Jones, 1996] Here are few characteristics of the Lean manufacturing: working in continuous flow (cells or flexible assembly lines), poly-qualified workers with a proactive attitude at the workplace, large diversity of products made in any requested quantity, quality incorporated in the processes of execution, reduced costs through substantial improvements in the production process (without complicated systems or large investment), clients and suppliers integrated in the production process. So, the processes of realization of the products or services requested by the customer must be analyzed on the basis of two fundamental concepts: 1) Added value: Any activity that increases the value or the utility of the product or service requested by the market, namely the activities for which a customer is willing to pay. 2) Loss (Non-added value): Any activity which don t add value to the product or service, meaning what raises the COST of the product without adding VALUE for the customer. These activities must be eliminated, simplified, reduced or integrated. The Value Stream includes all the component activities of a process, needed for the realization of the product, from the concept to the launching and from the order to the delivery. The value stream includes both the activities that processes the information related to the realization of the product, and the actual processing activities of the materials for the physical realization of that product. [C. Marchwinski & C. Shook, 2007] 1. Lean Manufacturing The implementation of the Lean manufacturing process is made for a single product or for a product line of similar products at the same time. It is not recommended to do the Lean change for all product lines and at the same time. The lessons learned from the

3 first attempt will be the basis for the second attempt and they will simplify the third one, until the lean manufacturing techniques become well known. [J.Wincel, 2004] The changes made are often similar with the changes from the suppliers. In the development of the strategy of materials flow, the first discussed element in the lean medium was the placing of the supplying market. In the implementation of the production, there was introduced and applied concepts as the supply just-in-time and the availability of the materials through the kanban system. The purpose of this approach was to eliminate the push system of the materials supply and to create a pull system. Although the MRP system can be a pull -type system, it doesn t reflect so good the consumption needs during production, like the kanban system. [Y. Monden, 1998] The following picture reflects a resemblance between the implementation of the lean manufacturing at his beginnings and the SCM steps. A similar comparison can be made between the materials flow strategy and the continuous improvements. 1. The implementation of Lean Manufacturing Lean Manufacturing actions SCM implementation actions Tact time calculation JIT distribution versus Kanban system Development of standardized work for Dock to stock - elimination of future all operations inspections Implementation of the pull system Systematic supply and reviewing the between the processes that use kanban suppliers activity Focus on developing relationships with suppliers In a SCM organization, the quality or the development of the activity of one of the suppliers serve to assist the operational quality in the organization to permanently offering corrective actions when the additional assistance in not enough. [J. Wincel, 2004] 2. Seiri, Seiton, Seiso, Seiketsu, Shitsuke 5S tool used in Lean Manufacturing 2.1. SEIRI Sorting and Filtering If you doubt, throw! Sorting is a method of freeing de space at the workplace and the elimination of all the unnecessary objects, like programs, test pieces, drawings, old or defective tools, accessories, unused materials, etc. The sorting process has an impact on the mentality at the workplace and removes the syndrome it works like this. The sorting implies the clear differentiation of the elements that are necessary and must be kept from the elements that aren t necessary and have to be eliminated. [A. Scotchmer, 2000] Surprisingly, this concept is misunderstood. In the beginning can be difficult to distinguish between the necessary and the unnecessary elements, therefore in such cases the recommendation is: if you doubt, throw. People tend to link to the parts having the impression that they will use them on a future order, and if they see a dismantled machine they think that they will use it sometimes. Meantime, the stocks and the unused machines begin to get in the way of the daily manufacturing activities. This leads to large losses for the entire plant.

4 The need of sorting and filtering is determined by the losses recorded by the company that result in errors and defects. Between the losses that can be encounter we can enumerate: - useless stocks lead to additional costs of storage; - unnecessary materials require additional spaces in warehouses and on the workplace; - there are used more cabinets and shelving to store unnecessary items; - it is required more manpower to manage the growing stock; - it is increasingly difficult to separate the necessary from the unnecessary stocks because of their large volume; - the quality of products decreases because of defects that occurs following the stocks existing on the production line and the equipment failures; - useless stocks and defective equipment requires financial resources to be maintained. For the easier identification of losses in the sorting is used the strategy of applying red labels. The strategy of applying red labels The strategy of applying red labels is a method of implementation of the sorting by marking the useless objects with highly visible red labels. The criterion by which are assigned red labels differs from factory to factory. In factories stricter in this regard, the period for which these objects are needed relates to the production schedule of next week. Stages of implementation of the strategy: [H. Hirano, 1990] a) Launching of red labeling projects - Members: employees in production, supply, management and accounting departments. - Period: 1-2 months. - Key element for JIT consultant: the determination of the factory employees to identify the useless objects. b) Identification of the targets for the application of red labels - Stocks: raw materials, parts, stocks on the production flow and products. - Equipment: equipment, miscellaneous equipment, tools, transport vehicles, desks, etc. - Location: floor and shelves. c) Setting the criteria for applying the red labels - It is established the criteria for what is needed and what not. - Example: We will not label the objects that are necessary for the next month production program, otherwise will be labeled on all other objects. d) Achievement of red labels - To be easily observed, the red labels should be as large as a standard paper sheet. - For stocks, the labeling teams should write down the name, the quantity, the retain period and the reason of retain. e) Assignment of red labels - Related departments staff comes to workshop listen to the description of current status and are objective in awarding red labels for useless objects. - The search is made with a critical eye. - The workshop workers won t be let to decide where to put the red tags. They are too subjective. - You must act without mercy when assigning the red labels. - If you doubt, assign a red label! - The red labeling must be done intensively for a short period. f) Assessing targets for the implementation of red labels

5 - Stocks Dividing the labels into two types: "dead stocks" and "retained stocks". Creation and execution of the program to remove dead stocks; it should include the quantity, the value, the period. Making a list of useless stocks for easier understanding and to be used in accounting department. - Equipment The basic principle: anything stands in the way during the improvement activities would be or moved, or removed. Pursuit of the company's instructions regarding the abandonment procedures of useless equipment. After applying the steps of this strategy you may move from sorting to the stabilization strategy, which uses the information panels SEITON Stabilization (Systematization of objects location) Arranging the necessary objects so that everyone can use them easily! Stabilization means setting the locations (boundaries). The second step of 5S refers to arranging in order the useful objects at the workplace, so these can be easily find/identified and in a logical order to facilitate their use. You must establish fixed locations, like recipients, modular shelves, cabinets with transparent doors, panels, markings on the floor for the access paths, containers or dumpsters for all the usual materials and tools, their storage being according the frequency of their utilization. As long as the location is easy to understand for everybody, abnormal situations will be seen immediately. Stabilization involves organizing the way how necessary items are kept, so that anyone can use them easily. Stabilization always accompanies sorting. Once all is organized and only the necessary objects remains, their locations are determined. Generally we could say that the stabilization is actually the standardization. Stabilization in this context, as the basis for standardization, is arranging things so that everyone can understand where there are held, can use them easily and then return them to the place from which were taken. There are three basic requirements for Stabilization: what, where and how much. The signs and labels must clearly display all three elements, so that we can determine what type of objects is held there, their exact location and the number of objects in that location. In the stabilization phase there are used many strategies, such as the painting strategy, which makes: - Separation lines mark travel routes within the factory and separate them from the work areas. - Demarcation lines for the sense of opening doors and corridors marking. - Demarcation lines for the spaces reserved to stocks on the flow. Stabilization has destinations like: - Warehouses: FIFO method for stock management the last stored item is the one given to consumption. Efficient use of domestic vehicles stocks on the production flow must be transported, in this respect is used the promptitude index of transport means which

6 compares the promptitude of transport means for different types of objects using various storage methods. Setting storage spaces closer the production line. - Tools and Devices: Information panels. Color codes. Knowing the locations of objects (in one sight) lead us to the co ncept of visual control. An important tool for the stabilization phase is the information panels strategy. The information panels strategy This is a method which clearly states where (location), what (object name) and how much (quantity), is a particular object, as stabilization is achieved. Stages of implementation of the strategy: [H. Hirano, 1990] a) Determining locations - Deciding the location of objects left behind sorting to be as close to the place of performance of operations. b) Preparation of the locations - Organizing the shelves and cabinets. c) Designation of the locations - Creating and sticking the information plates that clearly indicate where each object belongs. d) Pointing the name of the objects - Creating and sticking the information plates that clearly indicate the name/number of the shelf or cabinet which will hold the objects. - Indication of the quantities. - Indication of the number of items of stock on each information plate. e) Transforming the stabilization into a habit. - Transforming the stabilization into a habit so the workplace doesn t become messy again SEISO Shining (Shining and cleanliness) Everything must be clean and swept! Shining means initial cleanliness and the cleanliness of everything represents the workplace: floor, machines, cabinets, etc. It s imperative to detect the sources of dirt, the sources of leakage must be corrected and it must be provided enough material to perform cleaning at any workplace. This is the only way to improve the products quality and the people s safety. Shining means sweeping the floors and keeping things in order. Shining means inspection, and when we think of cleanliness and brightness we should imagine someone who has a broom in a hand and a cleaning solution in the other. Phases to achieve the cleanliness and shining: [H. Hirano, 1990] a) Daily cleaning Things become clean - Cleaning must become part of daily activities; cleaning and removing the dirt from the floor, access paths, shelves, cabinets. - Rubbing the surfaces so everything shines. b) Cleaning inspections Using the observations

7 - Once the cleanliness is implemented as daily practice, we can contribute at the maintenance of the conditions by using the practical sense to see defects or other abnormalities in the various equipment used. c) Maintaining the cleanliness Making improvements - As soon as an employee sees a defect, the operator who works on that machine must be the first who attempt to repair or improve the situation. - If the operator can t do the repair, it must be called a maintenance technician. - If the operator succeeds to fix the problem, this will be part of his activities for inspection of cleanliness. In the stage of Daily Cleaning the following steps are distinguished: - Determining the target points to achieve the cleanliness. - Determining the tasks to achieve the cleanliness. - Determining the methods to achieve the cleanliness. - Preparing the tools to achieve the cleanliness. - Implementing the cleaning. Inspections in achieving the cleanliness involve: - Determining the target points to achieve the cleanliness. - Assigning takes to achieve the cleanliness. - Determining the methods to achieve the cleanliness. - Implementing the inspection. - Implementing the maintenance of the cleanliness SEIKETSU Standardization The status resulted from the maintenance of the 3S. Standardization means maintaining the status obtained by setting rules, habits and standard procedures. Standardized work is obtained by finding the best working method from different people, on the same machine or workbench; using the standard equipment as recipients, various color files, etc.; displaying standard procedures on panels (visual management); using check lists. Standardization assumes that Sorting, Stabilization and Brightness are maintained. 1. Assigning the responsibilities for the 3S - It is essential to assign to the employees tasks based on the activities they do at the workplace. It s imperative to set clear instructions to not create confusion. 2. Integrating the tasks 3S in regular work tasks - If people achieve 3S tasks only when these deviate form their normal course, it is obvious that 3S system is not enough outlined. These tasks are learned gradually, until they became automatisms. - These can be obtained by visual 5S and 5S maintenance, as parts of current activities. 3. Checking the level of maintenance of 3S - This can be done by using checklists which evaluates the levels of implementing the 3S. For obtaining an impenetrable standardization system there are necessary measures to: a) Prevent the accumulation of useless objects. b) Prevent the necessity to put things back to specific locations.

8 2.5. SHITSUKE Support for change Creating a habit of maintaining the correct procedures. Support follows to ensure discipline and commitment of all to keep the obtained results. Without the support for change everything can return quickly to a similar situation. For the successful implementation of the 3S method, it is necessary not to start simultaneously with all the improvements. First it must be developed an environment where the culture of continuous improvement represents the standard. The initiatives must be stimulated and rewarded. Time must be allocated for involving in improvement, because this is possible only with the collaboration of all the employees involved in the pilot project implementation. Support for change always requires that specific procedures be followed (and standardized). The management must be committed, should encourage the training actions for the participation of the employees in 5S and communicate all the actions and results of the 5S audit. To do the audit is better to set up audit teams from different departments, which conduct regular checks (the foreman makes daily checks, head of section makes weekly or monthly checks and the top management makes quaterly checks). To realise the Support for change must be used: [H. Hirano, 1990] 1. Visual 5S - There are many things to observe in a factory and anyone maust be capable to do it. 2. Correcting the others - Use positive criticism to make people understand where they was wrong and to accept the advices. 3. Lessons to Build the Discipline - Company managers should use their experience to teach the subordinates to make things better. 4. Promotion in the whole company. 5. Use of Promotion Tools. Bibliography Womack J., Jones D.T. (1990) The machine that changed the world, Ross. Womack J., Jones D.T. (1996) Lean Thinking, New York: Simon&Schuster. Marchwinski, C., Shook, J. (2007) Lean Lexicon a graphical glossary for Lean Thinkers, Third Edition. Wincel, Jeffrey (2004) Lean Supply Chain Management A handbook for strategic procurement, Productivity Press. Monden, Yasuhiro (1998) Toyota Production Systems, Productivity Press. Scotchmer, Andrew (2000) 5S Kaizen in 90 minutes, Management Books. Hirano, Hiroyuki ( 1990) 5 Pillars of the Visual Workplace: The Sourcebook for 5S Implementation, Productivity Press.