One of the Japanese trials for higher productivity / Information

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1 What is Lean Construction? With One of the Japanese trials for higher productivity / Information Sharing System AKIRA INOKUMA Executive Director Japan Federation of Construction Management Engineers Associations(JCM ) Japan 1. What is Lean Construction? 1.1 Brief history of lean construction and background of this paper Lean construction is originally based on a car manufacturing method which has been born in Toyota car company and called Toyota Production System, TPS. Around 1980, the technical documents of TPS were introduced to US manufacturing industry. And TPS is said to be transformed to a newly systematized manufacturing method which is lean method in 1980s by Massachusetts Institute of Technology (MIT) and others in U.S. It was introduced to construction industry from manufacturing industry in 1990s, and named lean construction but concerning lean construction very few papers have been produced in Japan until now. In trying to introduce lean construction in Japan, one of the challenges is that lean construction does not have the worldwide consensus of its definition. The purpose of this paper is to make the definition clear. 1

2 1.2. Toyota Production System (TPS, ref Taiichi Oono, Toyota seisan housiki,1978) Two key pillars of Toyota Production System Just-in-time Productivity Jidoka (Self-control system) Quality Just-in-time means Jidoka or Self-control that each manufacturing system means stopping lines process provides as many automatically in such cases as products as the next some defect occurred. process requires (Pull Workers should do other works system). than their original work as long Kanban ( an order to as no line-stopping sign (Andon) produce or to transport) is is shown (multi process used for Just-in-time with operation). its rules like that kanban Each engineer should assure Chart1.1.3 Toyota Production System(Production line) prohibits producing goods quality when he handles without a kanban. products in the process. Production leveling in responding to the diverse demands Examples of TPS Best Practices Repeat why, 5 times Within the usual cycle individual play is required, but in such cases as individual delay or between the cycles mutual assisting and team play is required. Kanban has only necessary information of production or transportation. Do not make isolated islands, because in that case we cannot help each other. Standardize the work protocol. It includes takt (cycle time), work sequence and inventory in a cycle. 2

3 1.3. Lean Construction Two key concepts in lean construction Just-in-time Same as TPS Self-control system Same as TPS Work standardization Eliminates waste of delivery time. Cooperation and improvement Last Planner System Restart to manufacture products after problems are resolved. Chart1.1.4 Application of Lean Management to construction Improvement of Owner side Chart Alliance Toyota order system Production System (Production line) (Information sharing system) 3

4 1.4. Definition of lean construction Definitions at present The idea of lean construction is relatively new, so the strict definition is not fixed yet.but in order to promote the lean construction, definition is indispensable. I try to define lean construction. For this I refer two present definitions. Def.1 by L Koskela et.al,the foundations of lean construction, 2002 Lean is a way to design production systems to minimize waste of materials, time, and effort in order to generate the maximum possible amount of value. Def.2 by Constructing Excellence (association in U.K.) Lean Construction, 2004 Lean construction is a philosophy based on the concepts of lean manufacturing. It is about managing and improving the construction process to profitably deliver what the customer needs Conditions for the definition Definition consists of the conditions which distinguish a thing from others. So I have decomposed the above definitions into some conditions. I think we need at least two conditions that correspond to the two pillars of TPS. Condition1: What corresponds to Just-in-time is to minimize waste (Def1) / profitably(def2) / productivity (Def3) / efficiency This condition is necessary because it is one of the two essential pillars of TPS. To minimize waste is best fit for just-in-time, but in contrast to Jidoka (Self-control) the corresponding range can be set wider. Condition2: What corresponds to Jidoka is value (Def1) / customer needs (Def2) / quality(def3) / Self-control This is necessary because it is one of the two essential pillars of TPS.Jidoka deals with the defective products, so I think that it means in itself the quality. But in contrast to just-in-time the range can be set wider, too. Condition3: Lean / lean manufacturing (Def2) / lean practice(def3) This is necessary because there are other methods to pursue Just-in-time or Jidoka, that is, to minimize the waste or to improve the quality. It may seem definitional circulation but I think lean can be used in the definition of lean construction because construction industry imported that concept from manufacturing industry and we define the lean construction, not lean. Are they enough? 4

5 I suppose there are a few more candidate conditions, which are Condition4: construction site This might be another condition because Toyota method was born in the manufacturing site in the way that engineers find troubles and ask why 5 times to solve the problem and eliminate waste.but if we use construction method (Def. 3), it may be all right without this condition because construction method implies construction site Condition5: So to speak Cultural things This might be another condition because both just-in-time and self-control need cooperation and information sharing among staffs. But although Japanese would be more widely used to it, cooperation and information sharing are also regarded important in many companies in the world too so it can be excluded from the definition Proposed definition and further questions From those mentioned above, I would like to propose the below definition. Def3 Lean construction is the construction method to pursue no-waste productivity (condition 1) and assure the necessary quality (condition 2) through the lean practices (condition 3 ). Lean practices is possibly changed to lean method. But because two typical elements of TPS are already mentioned in condition 1,2 we have only to add best practices (see 1.2). To clarify lean practices more, we could add some examples of practices such as minimizing the waste, production leveling or multi process operation. This leads us to another question if we can identify all the lean practices and, if we can change and develop these practices, in what direction we should change to keep so-called lean. For example, 1. If we take critical pass method into lean construction because it surely contributes to no waste, we have to take almost all the fields of construction management into lean construction, which means that lean construction is construction management. I think we need some selective phrase to define lean construction in addition to no waste and value. Another field we should consider is IT. We cannot take all means of IT into lean, so we also need some selective phrase to define lean construction. 2. To solve 1 above, we could examine the connection between the field at issue and one relevant practice of the lean best practices. For this we should identify all the practices first. 5

6 3. TPS is born in a pure-private factory of mass production. So public sector is the field we should add in application of lean method to construction industry. And some part of TPS might be difficult to apply to public works. 2. One of the Japanese trials for higher productivity / Information Sharing System 2.1 Information Sharing System With information sharing system contractors and owners can share the relevant documents (e.g. records of meeting) on the internet during the construction period. This will allow the contractors to submit the documents and get the confirmation without going to the owners office, which will increase the efficiency. However, before the implement the agreement of the owners is required. Currently several IT companies are providing the information sharing system as its service for a fee. These providing companies are called ASP (Application Service Provider). In order to use information sharing system all you have to do is to get ID and password from ASP. After getting ID, you access the site of internet, login and submit the documents no matter when or where. At any time all users including the contractors and the owners can see the shared information and the approval status on the internet. The protocols are below The contractors log in and submit the document files on the internet. 2. The owners check the contents and make electronic approvals. They can of course ask questions or hand the document to other owner staffs for recognition 3. The system offers other useful features such as schedule management and online bulletin to facilitate communication between the contractors and the owners. 4. After the completion of work, the data can be processed to delivery format through batch conversion, and it enables the contractors to make electronic document delivery and have them finally inspected by the owner. 6

7 Contractor Internet Owner 1,2 Document 1. Submit the documents 3. Schedule Management 3. Online Bulletin 2. Check the documents and make the approval. 4. Do the electronic document 4. Perform the delivery. electronic inspection. <Figure> Concept of Information Sharing System One of the benefits for owners is that the system promotes the efficiency by putting the documents in order with the hand of the contractors and sharing information among the relevant owners. 2.2 Trial Run of the Information Sharing System and Evaluation The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) of Japan has been introducing this system on a trial basis for several years, and has got a good reputation from both the contractors and the owners (below figures). The MLIT has decided to use the information sharing system in its almost all public works after As for the prefectures the information sharing system is yet to be introduced from now on. 7

8 6,200 3,300 1,100 1, (End of Jan) 2012 Year <Figure> Number of Trial Runs of the Information Sharing System in MLIT Don't Feel the Necessity - 5% Very Unsatisfied 6% Very Satisfied 6% Need to be Improved 19% Very Good Still Hard 42% to Evaluate 34% Not Satisfied 29% A Little Satisfied 59% By Contractor (by the JCM ) By Owner (seminar by Jacic) <Figure> Evaluation of the Information Sharing System 8