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LEAN PRODUCTION – CONCEPTAND BENEFITSDelia MANEA1Abstract: This paper presents in a general manner the concept of LeanProduction and the benefits of its adoption. Lean production is a term met moreand more nowadays, a strategy being in a continuous development, based on aset of principles and tools to achieve its objective: to eliminate waste in order toimprove an enterprise’s performance.Keywords: lean production, principles, tools, benefits.JEL Classification: M11.1. IntroductionIn the late 70’s, the U.S. companies had a strong interest in the NCmachine tools and in the advanced automation as well as in planning thematerials necessary for the production process. (Mabert, V.A., 2007).Womack, J.P. et al. (1990) in The Machine that Changed the World, usesthe term Lean Production in contrast to the mass production system of theWest. The Japanese companies focused on applying the Lean Productionprinciples, using relatively simple technologies and lower costs automationat the expense of the computer technology.The concept of Lean Production is based on the Toyota productionsystem (Spear, S. & Bowen K.H., 1999; Womack, J.P., Jones, D.T. & RoosD., 1990). The Toyota production system focused on reducing waste,considering all aspects of the production process, using a variety oftechniques and tools for eliminating waste, such as: just-in-time, cellularmanufacturing, Value Stream Mapping, 5S, kanban (pull) systems, Kaizen,synchronous manufacturing, Poka-Yoke, (Bicheno, J., 2000; Rother, M. &1Spiru Haret University, Brasov, Romania, [email protected] 17, Issue 1, Year 2013Review of General Management

Shook, J. 1998), which resulted in a decrease of stocks and of the executiontime, an increase of the delivery performance, a rational use of space, abetter resource utilization and an improved productivity and quality(Pavnaskar, S.J., Gershenson. J.K. & Jambekar, A.B., 2003).2. The Lean Production ConceptLean Production can be defined as a philosophy or as a strategy whichdepends on a set of practices used tominimize wasteinorder toimprove anenterprise’s performance (Womack, J.P., Jones, D.T. & Roos, D., 1990).Lean Production comes from theToyotaproduction system, a conceptadoptedby manymajorcompanies across theworldin an attempt toremaincompetitivein an increasinglyglobalisedmarket. (Pérez M. P. & SánchezA.M., 2000; HosseiniNasab, H., et al. 2012, 73-81)Since the first use of the concept, there have been some attempts todefine the term Lean conceptually (Lewis, M.A., 2000; Hines, P., Holweg, M.& Rich, N., 2004; Shah, R. & Ward, P.T., 2007); unfortunately, thedefinitions are vague, and the lack of a clear definition leads tocommunication difficulties (Boaden, R., 1997) and difficulties inimplementing the Lean Production concept in enterprises as well as inestablishing its precise objectives (Andersson, R., Eriksson, H. &Torstensson, H., 2006). Parker (2003) considers that, due to the so manydifferent conceptual approaches of the Lean term, it becomes difficult toidentify the real benefits of its use. The lack of a precise definition makes itdifficult to establish if the changes occurred within a company are or not inaccord with the principles of the Lean Production, which leads to a laboriousevaluation of the efficiency of the concept. It is therefore necessary toestimate the success of the Lean Production before implementing it, in orderto avoid wasting time and money (Pettersen, J., 2009, 127-142).In an attempt to define Lean Production conceptually, we can say thatit uses the just-in-time practices and aims at the rational use of resources,the strategies to improve the production process and the elimination ofwaste, and the use of managerial scientific techniques. It is, however,difficult to formulate a complete definition encompassing all the elements ofLean Production, which is in a constant development. Thus, today’sdefinition reflects the current image, which at some point in the future willno longer be valid.Review of General ManagementVolume 17, Issue 1, Year 2013165

3. Lean Production: Principles and ToolsLean Production includes, on the one hand, a strategy which dependson a set of tools and, on the other hand, the Lean thinking, which focusesboth internally by reducing costs, and externally to increase customersatisfaction.The objective of this multi-dimensional approach is the reduction ofcosts by eliminating the non-value activities, using tools such as just-intime, cellular manufacturing, Value Stream Mapping, 5S, kanban (pull)systems, kaizen (Bicheno, J., 2000; Rother, M. & Shook, J. 1998;Kocakulah, M.C., Austill, D.A. & Schenk D.E., 2011), total productivemaintenance, production smoothing or production levelling, setup reductionfor waste elimination (Abdulmalek, F.A. & Rajgopal, J., 2007: ScherrerRathje, M., Boyle, T.A. &Deßorin, P., 2009). The implementation of theefficient production practices based on the flow optimization is expected tolead to better operating results, using, for example, an inventory leanness(Hofer, C., Eroglu, C. & Hofer, A. R., 2012), which–in turn–should enhancethe enterprise’s performances(Cuatrecasas-Arbos, L., Fortuny-Santos, J. &Vintro-Sanchez, C. 2011).The literature emphasizes the fact that the Lean Production is mainlybased on the just-in-time production. The just-in-time method consists of anelaborate planning of the production process and the amount of rawmaterials required are used exactly where they are needed, resulting thus areduction in the stocks of raw materials and parts. In each stage of theproduction process only the amount needed must be obtained and it shouldbe done only when it is required by the next working stage, according to thetechnological flux.Value Stream Mapping is a Lean Production tool, used to design andanalyze the production process. It is designed to create an easy way formanagers to visualize the value flow. The value is defined as that thingwhich brings a product in the form desired by the customers who are willingto pay for it (Kocakulah, M.C., Brown, J.F. & Thomson, J.W., 2008). Thegoal of the Value Stream Mapping is to help managers identify waste in alltheir processes in order to eliminate them: the waste time of the productionprocess resulting from a faulty organization of the working equipment(motion), waiting, the time spent on handling the products from one stage toanother of the production process, from the production workshops towarehouses (transportation), a production larger than it is required for the166Volume 17, Issue 1, Year 2013Review of General Management

next stage of the production process (over production), the undesirablecharacteristics that affect the product functionality or its appearance, therefuse (defects), over processing, inventory.Another basic tool for the managers who want to adopt LeanProduction is the 5 S. The 5 S has its origins in the Toyota system and refersto the words that describe the steps to be completed for each stage or phase: seiri – separate – is the first step that consists in eliminating allthat is not needed to complete the tasks. seiton – sort – identifying the stages of production and theelements necessary for the performance of the tasks required inthose stages, which are organized in an optimal manner in orderto avoid wasting time on handling. seiso – sweep – everything must be kept clean and the productionscraps and refuse should be removed. seiketsu – standardize – standardization of processes throughefficient organization of the working equipment whileprogramming them in order to have maximum efficiency. shitsuke – sustain – the final step consists in consists inmaintaining cleanliness and order every day.The 5S program has a number of benefits, such as: maintainingdiscipline, reducing production and handling time which leads to lower costs.Cellular manufacturing is a Lean method which is based on thegroup technology principles. The workstations and the equipment areorganized in order to allow easy transition from one stage of production toanother, resulting a minimal handling of materials, greater speed ofworking, eliminating unnecessary costs and having reduced stocksThe Jidoka principle is a process of quality control and refers to theautomation of the functions of the production supervision, which means thatthe personnel is warned in case of an abnormal situation in order to stop theproduction line, thus preventing wastage, refuse and an additional output,focusing the attention on understanding why the problems occurred and howthey can be avoided in the future.Poka-yoke refers to any mechanism that helps staff to avoid errors. Itspurpose is to eliminate product defects by preventing, correcting, or drawingattention to human errors.The Lean concept is criticised in the literature from the perspective ofthe personnel, because this side is less known, focusing primarily ontechniques for improving the performance of the system.Review of General ManagementVolume 17, Issue 1, Year 2013167

Jidoka and Poka-yoke suggest that employees can not be trusted inorder to have good quality products, creating a need to eliminate thepossibility of human error in the system.Kanban is a stock control system, and it is usually performed by theFIFO method. Kanban is an effective tool which contributed to thefunctioning of the production process as a whole. Sugimori (1977) statedthat the Kanban system has many advantages over computer technologies,such as: reduced cost of information processing, it is easy to obtain andtransmit information in a dynamic environment, the demand for materials isjudiciously sized. Sugimori criticized the lack of respect for the humanbeing of the enterprises whose production was controlled by computersystems. The Japanese consider the Kanban system more transparent,allowing staff to understand the production process without the need to usecomplex software.Womack and Jones (1996) identified five principles of the LeanProduction, in order to implement the concept in different industrialbranches: the value is determined by the point of view of the customer(Customer Value), Value Stream, Flow, Pull and improvement. Womackand Jones (1996) consider Value Stream as being specific products withspecific qualities offered at special prices through a dialogue with specificcustomers (www.bath.ac.uk).The Value Stream term is often used within the Lean Productionconcept and it is defined as a set of specific actions required to produce agiven product, based on the three management tasks: the task to solve all theproblems starting from the concept through a detailed design to the launchof production; from order taking, through detailed planning, to delivery andphysical transformation of the raw materials into a finished product ready tobe handed to the customers. (Womack, J. & Jones, D.T., 1996) The goal isto identify the inefficient activities of the process and to eliminate the waste.Flow – Cellular manufacturing is adopted by the enterprises that useLean Production, where each module has all the necessary resources tomanufacture a product, or, if several modules are organized in order toproduce a certain product, in order to obtain a production process by whichthe product smoothly goes through all its stages until it reaches the finaluser, the client.Pull – Hopp and Spearman (2004) defined the Pull system as one thatexplicitly limits the quantity of products entering the production process.The traditional production methods tend to Push products in themanufacturing process, without limiting their quantity in the hope that itwill be a customer to buy the already made products. In a Pull system not168Volume 17, Issue 1, Year 2013Review of General Management

even one single production stage will be finalized until there is a demand formoving to a later stage.Once businesses adopt the Lean principles, the improvement ofprocesses is certain. Another principle of the Lean Production concept is thecontinuous improvement, so that reducing efforts, costs, space used, andproduction time can be continuously achieved.4. Benefits of implementing Lean ProductionThe Lean Production concept has been developed for many years andit is often considered the most important strategy that can be adopted by themanufacturing companies that wish to obtain global performance (Rinehart,J.W., Huxley, C.V. & Robertson, D., 1997). It presents a number of benefits(Figure 1), such as (Melton, T., (2005):- A reduced delivery time;- Reduced inventory;- A better management;- Less rework.Figure no. 1. Benefits of Lean ProductionSource: Melton, T. (2005). The benefits of lean manufacturing. What lean thinking hastooffer the process industries. Chemical Engineering Research and Design,83(A6), 663.5. ConclusionsThe changes in the business environment in recent years have madethe term Lean to be used more and more. Lean Production is a concept thatReview of General ManagementVolume 17, Issue 1, Year 2013169

knows a constant development, so the today’s attempt to formulate adefinition of this concept will reflect a real contemporary image, which atsome future point will no longer be valid.It is obvious that the adoption of the Lean Production principles willimprove the entire process of production, the purpose of this strategy beingthat of reducing costs by eliminating waste and by increasing customersatisfaction, increasing thus the performance of the business.BibliographyAbdulmalek, F.A. & Rajgopal, J., (2007).Analyzing the benefits of leanmanufacturing and value stream mapping via simulation: a process sectorcase study.International Journal of Production Economic.107(1), 223-236.Andersson, R., Eriksson, H. & Torstensson, H., (2006), Similarities and differencesbetween TQM, six sigma and lean, The TQM Magazine. 18(3), 282-296.Bicheno, J., (2000). The Lean Toolbox, 2nd Edition. Buckingham: PICSIE Books.Boaden, R., (1997). What is total quality management, and does it matter?.TotalQuality Management & Business Excellence. 8(4), 153-171.Cuatrecasas-Arbos, L., Fortuny-Santos, J. & Vintro-Sanchez, C., (2011). Theoperations- time chart: a graphical tool to evaluate the performance ofproduction systems e from batch-and-queue to lean manufacturing.Computers & Industrial Engineering. 61(3), 663-675.Hines, P., Holweg, M. & Rich, N., (2004).Learning to evolve: a review ofcontemporary lean thinking.International Journal of Operations &Production Management. 24(10), 994-1011.Hofer, C., Eroglu, C. & Hofer, A.R., (2012).The effect of lean production onfinancial performance: The mediating role of inventory leanness.International Journal of Production Economics. 138(2), 242-253.Hopp, W.J. & Spearman, M.L., (2004). To pull or not to pull: what is thequestion? Manufacturing and Service Operations Management. 6(2), nalyzeleanmanufacturing.Journal of Cleaner Production. 29-30, 73-81.Kocakulah, M.C., Brown, J.F. & Thomson, J.W., (2008).Lean Manufacturingprinciples and their application.Journal of Cost Management. 22(3), 16-27.Kocakulah, M.C., Austill, D.A. & Schenk D.E., (2011). Lean Production practicesfor efficiency. Journal of Cost Management. 25(2), 20-28.Lewis, M.A., (2000), Lean production and sustainable competitive advantage. International Journal of Operations & Production Management. 20(8), 959-978.170Volume 17, Issue 1, Year 2013Review of General Management

Mabert, V.A., (2007). The early road to material requirements planning.Journal ofOperations Management. 25(2), 346–356.Melton, T., (2005).The benefits of lean manufacturing. What lean thinking hastooffer the process industries.Chemical Engineering Research and Design.83(A6), 662-673.Parker, S.K., (2003), Longitudinal effects of lean production on employeeoutcomes and the mediating role of work characteristics. The Journal ofApplied Psychology. 88(4), 620-634.Pavnaskar, S.J., Gershenson. J.K. & Jambekar, A.B., (2003). ClassiÞcationscheme for lean manufacturing tools.International Journal of ProductionResearch. 41(13), 3075–3090.Pérez M. P. & Sánchez A.M., (2000). Lean production and supplier relations: asurvey of practices in the Aragonese automotive industry. Technovation.20(12), 665-676.Pettersen, J., (2009). Defining lean production: some conceptual and practicalissues.The TQM Journal.21(2), 127-142.Rinehart, J.W., Huxley, C.V. & Robertson, D., (1997).Just another carfactory?Lean production and its discontents. Ithaca: ILR Press.Rother, M. & Shook, J., (1998).Learning to See: Value Stream Mapping to CreateValue and Eliminate Muda. Massachusetts: Lean Enterprise Institute.Scherrer-Rathje, M., Boyle, T.A. & Deßorin, P., (2009). Lean, take two!Reßections from the second attempt at lean implementation.BusinessHorizons. 52, 79-88.Shah, R. & Ward, P.T., (2007), Defining and developing measures of leanproduction. Journal of Operations Management. 25(4), 785-805.Spear, S. & Bowen K.H., (1999).Decoding the DNA of the Toyota productionsystem.Harvard Business Review. 77(5), 97–106.Sugimori, Y., Kusunoki, K., Cho, F. & Uchikawa, S., (1977). Toyota productionsystem and Kanban system: materialisation of just-in-time and respect-forhuman system. International Journal of Production Research. 15(6), 553–564.Womack, J. & Jones, D.T., (1996).Lean Thinking: Banish Waste and CreateWealth for Your Corporation. New York: Simon and Schuster.Womack, J.P., Jones, D.T. & Roos, D., (1990).The Machine that Changed theWorld. New York: HarperCollins.Ward,Y. & Graves A., (2004). A new cost management & accounting approach forlean enterprises, Irish Academy of Management Meeting AnnualConference, Trinity College, Dublin, -05.pdf.Review of General ManagementVolume 17, Issue 1, Year 2013171