TABLE OF CONTENT
Description Page No.
Report Objectives & Task framework 3
Chapter 1: Introduction and Understanding of JIT
1.0 History of JIT Concept 4
1.1 Definitions 5
1.2 The Concept And Philosophy 7
1.3 The JIT principles 7
Chapter 2 : JIT in Manufacturing
2.0 Implementation in Automobile Manufacturing 11
2.1 Ford KA in JIT 13
Chapter 3 : JIT in Construction Industry
3.0 Application in Construction Industry : An Overview 17 3.1 Factors That Influence Housing Developers to use JIT concept
in Construction Industry 18
3.2 Issues And Challenges in Construction Industry 25
3.3 Problem Areas 30
3.4 Strategy in Construction JIT 33
Chapter 4 : JIT and IBS
4.0 JIT and IBS 37
4.1 Classification of IBS 38
4.2 Value Stream Mapping 42
4.3 Example Structural Steel Supply Chain in Building Construction 44
Chapter 5 : Case Studies
5.0 Case study 1 49
Case Study 2 53
Case Study 3 56
Chapter 6 : Case Study Malaysian Scenario (PUTRAJAYA) 60
Chapter 7 : Conclusion 68
Report Objectives :
1. To get a better Understanding of Just-In-Time (JIT) Philosophy and Concept 2. To identify the factors that influence the housing developer firms to innovate,
that is by adopting new ideas, new concept, new process or introducing new idea, or new procedure of doing things in to their organization.
3. To identify the factors that stop, discourage, or deterred the firms from innovation JIT concept in the Construction Industry
Task Framework :
Understanding of JIT concept
Implementation in Manufacturing Industry
Issues and Challenges in implementing JIT concept in Construction Industry
Recommendation and Solutions towards the implementation
CHAPTER 1
INTRODUCTION OF JUST-IN-TIME
1.0 History of the JIT concept
JIT is a technique developed by Taichi Ohno and his fellow workers at Toyota. Ohno's fundamental purpose was to change production's directives from estimates of demand to actual demand--a purpose originally rooted in the absence of a mass market and the need to produce small lots of many product varieties. It was based on lean manufacturing, that an outgrowth of the Toyota Production system was developed by Taichii Ohno in the 1950s. Ohno had observed mass production at Ford Motor Corporation’s manufacturing facilities in the U.S. and recognized that there was much waste everywhere.
Ohno identified seven wastes in mass production systems – overproducing, waiting time, transporting, processing itself, having unnecessary stock on hand, using unnecessary motion and producing defective goods. Very importantly, Ohno visualized a failure to meet customers’ needs as waste. The Toyota Production System was based on the “Just –In – Time (JIT) philosophy; its three tenets were minimizing waste in all forms, continuous improvement of processes and systems, and maintaining respect for all workers. It resulted in reduced inventories (and space) higher human productivity; better equipment productivity and utilization, shorter lead times, fewer errors, and higher morale. JIT is a pull system that responds to actual customer demand. In essence, products are “pulled from ” the JIT system. JIT only commits the resources needed to meet the customer’s needs. In the mid – 1970’s Toyota reduced the time needed to produce a car from fifteen days to one day, using JIT.
Supply Chain Management (SCM) emerged as part of the Just in Time delivery system; its primary focus was logistical to control the interface between suppliers and Toyota, facilitating the provision of supplies precisely on time, in required quantities. A supply chain encompasses all the activities that lead to having an end user provided with a product or service – the chain is comparable to a network that provides a conduit for flows in both directions, such as materials, information, funds, paper, and people. It typically effects major economies by reducing inventories. SCM has been developed further as a management concept and incorporates features of JIT.
1.1 Definitions : Reviews of JIT Philosophy
JIT has gained considerable interest because it allows a company to produce high quality products with reduced waste and with increased levels of productivity. Several authors have discussed the JIT philosophy, including Sugimori et al, Mullins, Monde, Hoeffer, Nelleman and Smith, Schonberger, McElroyHall, Harper, and Richard.
Schonberger describes the JIT system as to: "produce and deliver finished goods just in time to be sold, sub-assemblies just in time to be assembled into finished goods, and purchased materials just in time to be transformed into fabricated parts". Schonberger also categorises the benefits of JIT into the following five groups:
(1) Part cost — low scrap cost, low inventory cost.
(2) Quality — fast detection and corrections, and higher quality of parts purchased. (3) Design — fast response to engineering change.
(4) Administrative efficiency — fewer suppliers, minimal expediting and release papers, and simple communication and receiving.
Monden describes JIT as "a production system to produce the kind of units needed, at the time needed and in the quantities needed". Whilst Harper describes it as "the hottest and most controversial subject facing manufacturers and distributors". The interest in JIT amongst manufacturers, suppliers and distributors is understandable especially if their products have to face home and international competition from manufacturers who have implemented the JIT principles effectively.
Monden also discusses the various factors which constitute smoothed production at Toyota under the various types of Kanbans and their usages and rules. He describes the techniques Toyota applied to achieve a short supply lot production time, waiting time and conveyance time. He also identifies four concepts that comprise the Japanese approach to reducing set-ups.
Hall states that JIT "is not confined to a set of techniques for improving production defined in the narrowest way as material conversion. It is a way to visualize the physical operations of the company from raw material to customer delivery". There is no aspect of management which JIT does not touch.
It eliminates waste in all areas of manufacturing — including marketing, planning, sales and production — whilst maintaining and possibly improving customer services because it identifies and changes manufacturing conditions which cause waste to exist.
According to Hoeffer, the JIT system is a combination of purchasing, inventory control and production management functions. Materials are purchased in small quantities with frequent deliveries just in time when they are needed. Under the JIT system, the parts needed for one day's operations in a manufacturing or assembly line are supplied by in-plant sources of suppliers for immediate use.
The benefits of using the JIT philosophy became of particular interest forconcerns because of rising manufacturing costs arising from increasing labour and material costs in the late 1970s, its efficiency being achieved through:
(1) suppliers' co-operation and support;
(2) commitment of every person within the organisation, and
(3) small size purchasing, smoothing production, designing flexible processes, standardising jobs and employing Kanban.
1.2 Concept and Philosophy
The JIT concept was developed by Taiichi Ohno (Hartley, J. R. 1981) of Toyota to improve Toyota’s competitiveness in the global market and soon it was adopted by many Japanese industries. By early 1980s, many Western managers found themselves losing ground in the manufacturing “race” against the Japanese. Imai (Imai,M. 1991) liked many other Japanese, attributed the Japanese industrial success to the concept of JIT. According to Pooler (Pooler, V. H. and D. J. Pooler. 1997), a common misconception of many managers in the eighties (and even today) is that JIT, in a narrow sense, was another planning tool that simply requires all the supplies to be shipped exactly as needed on time. In fact JIT has a much broader perspective than that understanding. It is a broad-based philosophy of management, which embraces everybody in the organization and covers every process towards a culture of never ending or continuous improvement by removing wastes and non-value-adding processes.
1.3 The JIT Principle
The JIT philosophy, also commonly known as the Toyota production system, originates from Japan. Toyota was the first company to implement this system which streamlined production with minimum holding inventory. Land costs in Japan are high due to its scarcity. Inventory takes up space and down capital. In the JIT philosophy, raw materials are not stocked up. Instead, they are delivered in the
right quantities, in the right condition, to the right place, and at the right time for production. JIT has proven to work well in the manufacturing sector (Lim and Low, 1992; and Chan 1997).
The fundamentals of JIT are very much intertwined and related to another. To simplify this management philosophy, its concept can be explained using the following six key principles:
1. Kanban or pull system
One of the principle of JIT concepts is the kanban or “pull” system. This principle can be effected only if the other principle of JIT are executed in totality. The essence of this principle is simply that the flow of materials is “pulled” by the demand side. Without authorized kanbans (or “pull” demands) from a workstation is not allowed to sent any materials forward. 2. Top Management commitment and employee involvement
Top management is the driving force and executive power for JIT implementation. Management’s efforts and time commitments are necessary to ensure that disciplined and correct operations are carried out accordance with the JIT concept. A motivation and workforce will provide the desirable for production. Management and employee must constantly seek continuous improvements to existing work. Process so that the production system can be further streamline and its lead time shortened. JIT is about improvement and should be regarded as a means to an end and not an end itself. Continuous improvement is only possible if employee involvement stays commuted to the philosophy.
3. Elimination of waste
Under the JIT concept, waste is defined as anything that does not as add value to the final product. Excess inventory is regarded as waste since no value is added by stoking up inventory. In addition, inventories takes up space, tie down capital, incurs storage cost, as well as security and insurance costs; not to mention the risk of damage during storage as well as the risk of obsolescence.
The JIT concept therefore calls for zero inventory or buffer stocks. Waiting time, inspection time and time spent at rectifying defects deemed wasteful. Thus, getting things done the first “time right” is another doctrine of the JIT concept.
4. Total Quality Control (TQC)
Production operations can be proceed in the JIT and the fashion only if the part delivered are the of good enough quality for the use. Rejection of materials due to poor quality will grievously disrupts the whole production workflow and schedule. Any savings and productivity gains from JIT will be wiped away. Hence, the JIT concept must also encompass the total Quality Control concept for smooth, just-in-time execution of the work processes. 5. Uninterrupted work flow
JIT production warrants an interrupted work process. Since each workstation pulls materials from the previous one, without keeping any backup inventory, any disruption at any point in the production line would impact the entire chain of activities, it is therefore, essential to ensure that the manufacturing process is uninterrupted. Simplifying the work processes and striving to reduce the process set-up time are useful ways to better ensure continuous operations.
6. Supplier relation: single-sourcing
With materials flowing into the factory on a JIT basis, coordination with suppliers is utmost importance in order to ensure that the right materials come at the right time. Too many suppliers will cause management to have less time with each supplier for liaising, expediting orders, and feedback and coordination efforts. JIT therefore emphasizes on the need to reduce the pool of supplier and, eventually, work towards a single supply source. This requires the forging of long term business relationship founded on mutual trust and benefits. The single supplier, with assured business over the long term, will then be able to invest in machinery and automation to improve productivity and reduce costs.
This is, in turn, works well for the production company as the supplier is able to supply better quality materials and at the lower cost. It would be easier to manage smaller group of suppliers. Manager will be able to spend more quality time with the reduce number of suppliers. Managers will be able to spend more quality time with the reduce number of suppliers and ensure that the JIT production is well supported by all the crucial JIT deliveries.
CHAPTER 2
JIT IN MANUFACTURING INDUSTRY
2.0 Just-In-Time (JIT) and Its Implementation in Automobile Manufacturing Industry
JIT is one of the examples of early-landed future manufacturing idealism that requires continuous collaborated refinements throughout its supply chain elements. It has been used since 1950s by Japanese automotive industries and yet, according to Karlsson (1994), none of the most developed countries would have even considered this methodology until early 1980s. Researchers tried really hard to explain JIT concept in a short descriptive sentence and none of them were able to come up with a single answer that represents everyone’s definitions. Those who were trying to bring them together were ended up with another new more complex definition. JIT goes beyond ordinary management theory or a company’s manufacturing procedures; it comprises production planning, HRM, material management, distribution, customer services not only involving individual organisation furthermore requires collaborated cross-companies dedication to continuously refine the business process of one and another.
Svensson (2001) in his journal argued that the basic of JIT is “no non-essential activity should be committed prior, during and after any production phases and wherever beneficial outsourcing is regarded as good as in-house production”. JIT is understood as event driven production concept which has been carefully planned and structured to ensure all its components are ready whenever needed. It is also known as inventory-less production method which allows minimum stock level only needed for the current manufacturing phase.
Automotive manufacturing industry has become an ideal instance on how JIT methodology may improve the efficiency of the whole production processes (Karlsson, 1994). By involving thousands manufacturing steps, there are always chances for refinement.
This is to minimize lead times which in turn will boost the production capacity of the industry as well as its flexibility to response to the market needs. Since this industry requires large stock to meet the production needs, a better inventory management system such as JIT will be helpful in reducing costs (Claycomb, 1999). Ramarapu (1995) stated that, most authors agreed that successful JIT implementation requires five key elements to be considered.
• Waste reduction: This element’s aim is to eliminate all non-value-added tasks (Bowen, 1998). The main problem with traditional production method is resulting from the focus on producing large number of items. With level of competitiveness and flexibility requirements, this is no longer an appropriate method to be performed.
• Value-adding production oriented: This element brings the terminology of “pull-system” which allow customer order to trigger the production process. Pull system requires immediate respond in order to satisfy customer requirement therefore avoiding “the goal of producing large batches” (Bowen, 1998). By grouping products based on their production process similarity, manufacturer may also add-value to the products by lessening production complexity, shortening travel and idle time.
• Customer participation in quality improvement: In every business, customer will have the final say therefore the success of the business can be determined based on customer satisfaction. This element heavily emphasis the needs of customer involvement in product development and delivery (Bowen, 1998). Customer may also be included in development team to direct them to the right manufacturing plan.
• Employee empowerment: Empowering employees mean dividing problem solving and decision making responsibilities from management level to its individual team directly related with the task. With careful planning and adequate team work, this element will increase quality, productivity and flexibility of the manufacturing process (Bowen, 1998).
• Vendor/supplier integration: Undoubtedly, specialized suppliers will normally produce a better product since they can concentrate in a particular thing. By outsourcing to those suppliers, a company will be able to put all its time and resources in its core function which in turn will improve the quality of the final products (Ramarapu, 1995).
2.1 Ford KA In Just In Time
Production of Ford latest small car, the Ford KA has been a dramatic improvement compared to Ford previous product, Fiesta (Kochan, 1997). This is a real example of successful JIT implementation with all its outsourcing strategies. The production target of 1,100 KA cars per day has been reached only within 8 weeks since the launch date, compared to 15 weeks required for Fiesta. Ford found that the initial bottleneck was caused by material handling, assembly time and inbound logistic. Some of the components in Fiesta are supplied by various suppliers and these components had to be made, loaded in the container and scheduled for delivery before finally delivered by trucks. This common process is found to be inefficient as every part has to be continuously handled by human and this causes big risks of damages, misplaced and imperfection in quality, especially for cosmetically sensitive and fragile parts such as instrument consoles, electrical wiring and airbags.
With the new developed JIT system supported with sophisticated aerial tunnels connecting Ford with its suppliers, production lead times can be minimised, product quality can be improved, responsiveness towards customer demands can me boosted and the most important thing is inventory, space requirements, handling and transportation cost can be dramatically reduced (Kochan, 1997). Ford is now connected with more than 50 suppliers in Valencia with specifically designed aerial tunnels. These tunnels are also very useful to transport bulky and heavy items such as seats and fuel tank. The brain of this amazing system is DAD (direct automated delivery) which will integrate the whole processes virtually as one extended manufacturing warehouse.
DAD will enable a smooth manufacturing process by applying Ford scheduling system so that all the supplied components being delivered right on time they are needed. In addition, DAD and its tunnels enable the integration of manufacturing equipment so that the component being delivered can be immediately installed with the main body or other components in Ford factory. Summary of Ford Valencia manufacturing system prior JIT implementation:
• Minimum of 15 weeks to reach full production capacity
• Required at least 3,000 parts to be assembled for each car
• Very small outsourcing involve for car components
• All parts from suppliers are delivered on trucks
• Stock must be kept at certain level to assure the continuity of production
• Parts are often damaged during packaging, handling or delivery
• Spent over $6 million for inefficient delivery system (250+ trucks per day)
• 80 per cent automation in overall
• Manual seats and battery placement and this may cause injury for employee In a dynamic market trends, pre-JIT system clearly is not responsive enough as an answer. There are minor inefficiencies throughout the system which accumulate into serious problem that may cause Ford being less competitive in the market.
2.1.1 Improvement Process Analysis
The main objectives of JIT are obtaining low-cost high quality products and on-time production as well as eliminating waste and stagnant stock (Svensson, 2001). Even though most of JIT implementation has similar aim and purposes, the strategies involved may differ from industry to industry or company to company. Ford has smartly chosen the right methods and strategies by reducing the barriers in relation with its suppliers.
Through JIT, Ford is achieving the highest efficiency in car manufacturing industry. Its plant in Valencia has become the standard and being adopted in its other plants in many other countries. Apart from its tangible benefits such as
saving on transport costs, stock/inventory costs, quicker manufacturing process and minimized risk/wastage, JIT will also bring immediate intangible benefits such as improved customer satisfaction through immediate responses and shorter timeframe to respond towards market trends.
Improvements being achieved through JIT implementation:
• Only 8 weeks required to reach full production capacity
• Only 1,200 parts need to be assembled, the rest have been done by its suppliers
• All the outsource-viable production parts are outsourced
• Automatic delivery system and aerial tunnels are developed to minimise transport
• There is barely any stock required as most parts are made to order
• The whole manufacturing process including the suppliers are working as one system
• The need of conventional truck delivery is minimum
• 98 percent automation
• Seats and battery placement are being done by automated high-precision machines.
There is not enough detail to measure the benefit of JIT implementation against the pre-JIT system, however from rough analysis Ford will gain the benefit immediately and get the investment back in virtually no time.
2.1.2 JIT Cost/Benefit Analysis for Ford Valencia
COSTS BENEFITS
Extending outsourcing (losing control)
$500 million pilot plan and analysis
Speed-up production process 8weeks Smaller number or manufacturing
parts
Concentrating on core business functions
25% shorter time production time needed
Accuracy of production on plan Building aerial tunnels
Setup Direct Automated Delivery DAD
$16 million delivery system
Less handling = less damages / costs Less conventional transport
dependent Time saving
Manufacturing seamless integration Further interest from more suppliers Saving $6+ million per year on transport
CHAPTER 3
JIT IN CONSTRUCTION INDUSTRY
3.0 Application of JIT in Construction Industry : An Introduction
Much had been discussed on raising the productivity level of the construction industry which consistently lagged behind other sectors of the economy. The use of buildable designs was singled out as a means to improve productivity. In so far as construction management is concerned, the Just-In-Time (JIT) philosophy can be applied for logistics management on worksites to help raise productivity levels (Akintoye, 1995).
The JIT philosophy originates from the manufacturing sector. It helps to smoothen the production process through the efficient handling of materials, i.e. by providing the right materials, in the right quantities and quality, just in time for production. Given the very different conditions in the construction setting, it is inevitable that modifications have to be made to some of the JIT principles where application is concerned (Low and Chan, 1997). Nevertheless, both the manufacturing and construction industries require active movement of materials from the suppliers to the production area in both the factory and the worksite. With the JIT management system in place, materials may be delivered to site on the actual day of use or just the day before (Lim and Low, 1992).
Explorative studies have been completed in recent years to see how JIT can be applied into the construction industry to reap the benefits of the system. Most of these studies have concluded that it is possible to apply the techniques of JIT in the construction industry with some modifications. Given the very different conditions in the construction setting, it is inevitable that modifications have to be made to some of the JIT principles where application is concerned (Low and Chan, 1997).
Nevertheless, both the manufacturing and construction industries require active movement of materials from the suppliers to the production area in both the factory and the worksite. With the JIT management system in place, materials may be delivered to site on the actual day of use or just the day before (Lim and Low, 1992).
Therefore, in this chapter, the discussion will view on the application of JIT in construction whether this approach can be applied on the construction industry.
3.1 Factors That Influence Housing Developers to use JIT concept in Construction Industry
The successful implementation of JIT is dependent on the suppliers’ flexibility, users’ stability, total management and employee commitment as well as teamwork. Through the elimination of waste, JIT aims to improve product quality and productivity. Waste is considered as non-value adding to an activity. In any operation, it comprises motion and work. However, only work is a value-adding activity. Hence, motion is regarded as a form of waste. Wastes include over-production of components and products, delays in materials and information, material transportation, unnecessary processing, excess stocks, unnecessary human activities and defects in material and information. The seven principles of JIT used to overcome the above problems are now outlined.
(a)Elimination of waste
The fundamental philosophy of JIT is to eliminate waste and under the JIT concept, construction waste can be classified into the following categories:
1. Waste from over-production 2. Waste from delays
3. Waste from transportation
4. Waste from unnecessary processing 5. Waste from excess inventory
6. Waste from unnecessary motion 7. Waste from defects.
Construction is schedule driven. Given a well-structured schedule, if everyone stays on their part of the schedule, the work flows smoothly and maximum performance is achieved. However, as we all know, it is rare that projects perform precisely to their original schedule. Business conditions change, deliveries slip, a design requires correction, etc. If a schedule has sufficient slack in the impacted activities, changes may not impact end dates. When there is little or no slack, players are pressured to make it up in accelerated production.
3.1.1 Types of Construction Buffers
There are two types of inventories that can serve the function of buffering downstream construction processes from flow variation. The most familiar type is piles of stuff; materials, tools, equipment, manpower, etc. These piles of stuff may originate in decisions to insert certain time intervals between scheduled activities, e.g. between fabrication and installation of pipe spools. Consequently, while they take the form of stuff, they often also represent time added to project duration, so it call these as "schedule buffers".
Less familiar are inventories of workable assignments, produced by planning processes that make work ready for downstream production These buffer by enabling a reliable, predictable flow of output from each process. They need not imply the existence of piles of stuff, depending upon the predictability of flow between supplier and customer processes. It will call these inventories of workable assignments "plan buffers."
3.1.2 Functions of Schedule Buffers
In the construction of process plants (petroleum, chemical, food processing, pulp and paper, etc), projects are frequently fast track; i.e. construction begins before design is completed. Late delivery of drawings and materials has led construction contractors to demand earlier delivery, reducing the time available for engineering to complete design, resulting in more delivery problems and demands for even earlier deliveries.
This is clearly a vicious circle. Large schedule buffers between suppliers and construction may shield the contractor from the impact of late deliveries, but does nothing to address the root causes of variation. Further, the shielding is expensive, both in time and money. There is a better way. A suggested rule: Place schedule buffers just after processes with variable output. For example, that suggests placing schedule buffers between engineering and fabrication, rather than between fabrication and installation. The fabrication and delivery processes are highly predictable, unless drawings are incorrect or incomplete, or drawings are pulled out of fabrication to be revised.
A schedule buffer in front of fabrication would provide more time for engineering to complete its work and do it correctly. It would also provide the fabricator an opportunity to select and bundle work to meet his needs for production efficiency and the contractor's needs for quantities and sequence.
Another suggested rule: Size schedule buffers to the degree of uncertainty and variation to be managed. Research has shown that schedule buffers are sized without regard to the toughness of projects; i.e. their level of uncertainty. This amounts to wasting time and money accumulating piles of stuff not all of which is needed
3.1.3 Functions of Plan Buffers
Schedule buffers do not replace plan buffers. Plan buffers are necessary even when schedule buffers are in place because having a pile of pipe does not provide a piping crew with workable assignments. Pipe spools must match with valves, controls, hangers, etc. Structures for supporting the pipe must be in place. Preferably, the spools that can be installed are those that should come next in an optimum constructability sequence. Assembling physical components, reserving shared resources, determining optimum sequencing, and sizing assignments to absorb the productive capacity of the crew is best done prior to making assignments and committing to what work will be done in the plan period, usually one week.
Plan buffers, sometimes called backlogs of workable assignments, are the outputs of make ready processes. They determine what CAN be done as distinct from what SHOULD be done. Obviously, commitment to what WILL be done next week can only come from CAN, regardless of the pressure for production and the need to make up schedule slippages. The common practice of pressuring for production regardless of CAN is rooted in a theory of construction project management that disregards capability and management of flows in favor of schedule push and management of contracts. By monitoring the match of DID with WILL using the measurement of PPC, the percentage of planned activities completed, and acting on the root causes of non-completions, we can learn how to produce better plans and how to do what we plan to do. The implications for work flow, project durations and productivity are enormous. Think of the complete construction process, from engineering through installation and start-up, as a complex of work processes, with work flowing from one to the next. When a downstream process attempts to plan its work and determine the resources it will
need, it may have shielded itself from unreliable inflow using piles of stuff or schedule spacing. However, it only needs those piles of stuff if supplier processes cannot reliably do what they say they are going to do. If supplier processes consistently achieve PPCs near 100%, customer processes can plan their work and match resources to it. Reduction of schedule buffers and better matching of resources to work flow both contribute to reduction of project time and cost.
(b) The Kanban or Pull System
Methods of production can generally be organized in two ways, namely the pull and the push system. In the pull system, organizations produce on demand whereas in the push system, organizations forecast the demand or maintain stock level. The advantage of the push system is that since the amount of production is known in advance, the scheduling of activities needed is predictable. However, a forecast may be required and therefore there is a possibility of over-production. The advantage of the pull system is that it is less dependent on estimates when compared to the push system. However, in the Kanban system, responding to unexpected demands is not possible.
(c) Uninterrupted workflow
Uninterrupted workflow means that the schedule for the final assembly must be smooth flowing. Hence, rationalization and simplification of the production process is necessary. Every process should be reduced to its simplest form before considering mechanization or automation and the aim is to replace a complex and expensive process with one that is simple and cheap.
(d) Total Quality Control (TQC)
In order to achieve zero inventories, errors and defective components must be eliminated in each task. Under TQC, all workers are responsible for ensuring that their work is defect-free before proceeding to the next stage of operation.
(e) Employee involvement
As noted earlier, the success of JIT implementation is dependent to a great extent on the teamwork and commitment of every employee. Each employee should be given adequate training and responsibilities in various areas like timeliness of production and quality assurance. Employees should be able to set up and maintain various type of machinery. Involvement can be extended to suggestion schemes and participation in quality improvement teams.
(f) Supplier relations
Building a good supplier-user relation is no longer a choice but a necessity. The quality of the supplies purchased is a critical factor to the quality of an organisation’s finished products. Hence, an organization must treat suppliers as long-term business partners so that the quality of materials delivered will always be maintained at a high standard. This would greatly reduce paperwork, inventory levels and storage space.
(g) Continuous improvement
An organization should not remain content with its status quo. To maintain its competitiveness, it should continuously strive to improve operations and the ways in which activities are carried out. Audits and benchmarking are some of the tools which an organization can adopt to ensure that its operations are improved continuously.
The successful implementation of JIT would require a consideration of the seven principles mentioned above. Once this is achieved, the advantages of implementing JIT would include:
• Reduction in inventory level (work-in-progress and raw material) • Reduction in storage space
• Reduction in factory overheads • Reduction in production costs • Reduction in rectification works • Improvement in quality
3.2 Challenges in Implementing JIT in Construction
In reality the application of JIT on construction differs from manufacturing industry due to its characteristic. The different characteristics exist for the both industries are in context of different types of production, and because of the greater complexity and uncertainty of construction. There are several reasons why the construction industry becomes uncertain and complex. The construction industry involves a lot of people with different of body knowledge, skills and experiences. Furthermore, the parties involved in the construction industry have their own objectives and target to be achieved in certain period of time. The situation becomes harder because a single actor’s action, ideas and egos at every stages of construction development may bring different effects to the whole project. Beside of multiple participants in construction development, the number of parts, relative lack of standardization and constraining factors easily make the construction of an automobile factory more difficult than the production of an automobile in that factory. When this complexity is joined with economic pressures to minimize time and cost that uncertainty arises in construction is not surprising.
In Manufacturing , Ohno, in order to allow a downstream process continued working when a feeder process failed, he has removed the safety stock by minimizing the inventories between the processes. When the problems occur during the production process, Ohno required the operators to stop the work if they are unable to fix that problems.
Logically, it is necessary to fix the problems rather than simply passing bad product down the line. The problems which arise also became highly visible because it may result in line stoppages. Forced confrontation with problems together with analysis to root causes produced a progressively more streamlined and smoother running production process, with fewer end-of the-line defects and higher throughput.
How might this concept work in construction? As mentioned earlier in this chapter, the construction development is a complex task. Therefore, it must be well
organized by the management in order to achieve the maximum performance in the project. However, the well structured schedule provided by the management is not only the one key factor of project successful. The other party should stay on their part of the schedule in order to have a smooth work flow and minimize the problems during the whole process of construction project. In reality, it is rare that the projects perform precisely to their original schedule. This situation happened due to changes on internal and external factors related to construction development, such as business conditions change, deliveries slip; a design requires correction, etc.
The changes made by the parties may not impact the end dates if the original schedule has sufficient slack in the impacted activities. The situation will be different compared to the construction project which is the schedule has a little or no slack. The players are pressured to make it up in accelerated production. In fact, this situation may caused delay to construction project which is could bring waste of times, money, energy, man power and etc. In order to implement the application of JIT, the priority objective of this application is to eliminate or minimized the variation and wastage. By the fact show above, is it possible to implement the JIT on construction?
As we know, the construction industry is also known as 3d’s industry; danger, dirty and demand. This discussion will concern on the part of dirty because this item has relation with JIT philosophy.
For an example, in 1998, the Environmental Protection Agency of United States of America estimated that 136 million tons of building-related waste is generated in the U.S. annually, which is 25% to 40% of the national solid waste stream. A 2003 update shows an increase to 164,000 million tons annually, of which 9% is construction waste, 38% is renovation waste, and 53% is demolition debris. This situation shows us increasing of construction waste in certain period of time. This figure is only in U.S. and it is believed that the other countries have also faced this problems.
Can we imagine that how much more our land can afford for construction waste? The disposal of the construction waste need a large scale of land whereas all over the world faced a shortage of land in order to fulfill the demand of accommodation, agriculture, manufacturing, education and etc. C&D waste disposal triggers a sequence of adverse effects that are not always apparent to building professionals. These include the loss of useful property, wasted materials and embodied energy, greenhouse gas generation, and environmental stressors associated with producing new materials instead of using existing materials. The number of C&D landfills is declining, which means fewer disposal options, greater hauling distances, and increased fuel consumption and vehicle emissions. Capping, closing, and monitoring landfills, and cleaning up leaking or contaminated landfill sites drain public funds.
So far it is clear to us that, the implementation of JIT on construction seems unclear because any application of any method not only just all about take the whole method from other industry and then simplify implement it into the construction industry. The construction industry is complex and uncertain. It needs a lot of improvement in many aspects such as, efficient management of waste materials, co-ordination between parties, well-planned management and etc. the discussion above about the waste materials is absolutely adverse from the priority of the objective of JIT application.
For the fast track construction of process plants such as petroleum, chemical, food processing, pulp and paper, etc, frequently the construction begins before design is completed. Therefore the contractors demand to have earlier delivery which is reducing the time available for engineering to complete the structure drawings. These situations exist due to late delivery of drawings and materials and it is possible caused more delivery problems and demands for even earlier deliveries. In order to avoid or shield the contractors from the impact of late delivery, the management may provide a large schedule buffer between the suppliers and construction. However, it does nothing to address the root cause of variation in construction projects. Even more, the shield is expensive for time and money.
Therefore, recommended rule has been suggested by Glenn and Gregory. They suggest of placement of schedule buffers just after processes with variable output. For example, the management placed the schedule buffers between engineering and fabrication, rather than between fabrication and installation. The fabrication and delivery processes are highly predictable, unless drawings are incorrect or incomplete, or drawings are pulled out of fabrication to be revised. The engineers have the sufficient time to complete its work and do it correctly if there is a schedule buffer in front of fabrication. It is not just good for the engineers but also to fabricators which is they have an opportunity to select and bundle work to meet his needs for production efficiency and the contractor's needs for quantities and sequence
Sizing the schedule buffers to the degree of uncertainty and variation to be managed is another recommendation from Glenn and Gregory. Research has shown that schedule buffers are sized without regard to the toughness of projects; i.e. their level of uncertainty.
The other challenge of implementation of JIT on construction is about the supply chain. As we know, the industrial supply chains in manufacturing industries often have a long-term horizon rahter than the practice of competitive bidding in the construction industry ensures that every new project means a new constellation of partners. The long-lasting supply chains of the manufacturing sphere means the members of the chains optimize their operations with each other to deliver the best possible product at least costs to the end customer.
For the members, the incentives structure direct them toward viewing the supply chain as one integrated chain competing with other supply chains and success is ensured by making one own supply chain the best one. For actors in the construction industry, every project is a one-off happening where the incentive structure motivates them to make the most profit out of each project. This discontinuity is detrimental to construction project productivity and can probably only be changed by altering the practices of how “construction chains” are
composed. A possibility for the construction industry could be to aim at more lasting relations between the actors in both the value chain of materials and in the value chain of actors.
Why the supply chain so important in JIT? In manufacturing industries, the operation is based on the long-term production and keep produce the same product as long as they have demand from their customers. Therefore, as long as they keep produce their product that’s mean they keep using the same suppliers for their production. This is important to have co-ordination with the same suppliers because the manufactures of production already know the quality of workmanship of their supplier and what are characteristics of their suppliers. Meanwhile, differs exist in supply chain of construction as mentioned earlier. The short term of supply chain in construction has caused the uncertainty.
New projects mean new consultants, contractors and suppliers. Changes of parties in every projects caused the relationship between those parties is just for short period. That’s mean for new projects, everybody needs to know each other again which is everybody did not know how their job are, what quality of work they can produce and other aspects which can give different effects to the construction projects.
The long-term relation with the supplier also plays a big factor in effecting the construction project. The good track record of supplier should be recommended for other construction project in order to achieve the objectives of the projects. However, it is rarely happened in construction industry because it involves other factors such as transportation, limited materials and etc. Therefore, in order to run a construction projects within the available budget, the management have to avoid any extra expenses especially in context of getting the right materials and amount from the suppliers. This situation related to another concept of JIT; producing the right part in the right place and the right time.
So, it is important to ensure that the supplier can produce the right part of materials as been asked in contract and also they can guarantee that they can supply the materials on the right time. However, even the suppliers can supply the
materials on the right times, the construction site must have efficient place to store the materials to avoid any damages which caused extra expanses. Even more, the delivery of the materials from suppliers is much depends on the transportation which may involve unexpected traffic. From this view, it shows that a lot of things need to put into consideration in implementing the application of JIT on construction industry.
3.3 Problem Areas in Construction Industry
From the presentation paper by Veiseth, Rostad and Andersen (2003) the actors that they have interviewed have identified several problem-areas. In this paper we will focus on three of them:
• The problems in the interface between the builder, the advisers and the executors. This problem is often referred to as “early phase- problems” that emphasize the whole project.
• Logistics problems for building materials and other products used during the construction process.
• Problems in the construction project planning and management.
Most of the actors we have interviewed argue that the problems in a typical construction project come into being in the interface between the builder, the advisers and the executors (see figure 1). The advisers are the architect and the consulting engineers, while the executors are the building contractors and supporters.
Builder
Advisers
Fig 2: Problem area; the interface between the builder, the advisers and the executors Builder Advisers Executors
In their opinion they interfaces are of a special interest because much of the premises for the ensuing productivity and logistics are created here. The problems could be due to several things like communications problems between different professions and cultures and that the architects are thinking too little about the building process in their drawings. But the thing we will point out is that the actors in the three categories, most of the times do vary from project to project. This is in contrast to e.g. manufacturing industries where the bindings between actors in e.g. a supply chain are more often a long-term relationship. Furthermore, in the very beginning of a typical project, in the idea-phase, it is often just the builder and the architect who are participating. This can maybe also explain the fact that many of our respondents claiming that there often are a lack of technical expertise in this phase.
When it comes to logistics planning it seems to be a potential for improvements in both the planning of how to organize the construction site and of the logistic of the building itself. For the logistic of the construction site, a well-known problem is that equipment and construction goods are delivered or placed at wrong geographical places and not on time. This could be the result of defective storage planning or that a storage plan does not exist at all together with lack of routines for the receiving of goods (e.g. logistics planning). The result of this is also that many building sites look much disorganized. The inability by the contractor to deliver materials at the right time and the right place is identified as one of the most common problems in the construction industry (Thomas, Horman, de Souza and Zavriski (2002:2).
Another impotent area is purchase routines. Today, most of the purchases are done by telephone, even though most of the interviewed actor’s wish to do most of this through the Internet. This could be due to that many are not familiar with a computer.
More Internet-based purchase routines are believed to be more cost-efficient than telephone-based purchase, for instance to help decrease the normally huge numbers of rush orders, which is looked upon as a problem. Those of the interviewed subjects who have carried out the change from telephone to more automated purchasing routines support this.
Planning has always been a theme when it comes to improvements of the productivity in all businesses, and the construction industry is no exception. Several actors in the industry emphasize that projects are behind schedule due to that plans are not finished in time. In addition, plans that also take care of the interfaces between the actors in the project are often missing. The interviewed actors in the Norwegian construction industry do specially mention insufficient planning regarding detail plans. Several do also want more milestones and better overview of dependencies in their projects. It is nevertheless important to realize that there is no point to “over-plan” the projects. An identified trend in the construction industry is that the actors only plan what is within their own field of expertise and disregards planning of elements/factors outside their own domain.
Insufficient planning could also be due to that the project management in construction projects could have been better. Furthermore, the respondents especially single out the technical project management. Many claim that the plans consist of too few subsidiary goals and that the project management should control the projects more strictly. This relates especially to the project and the project management’s ability to meet the deadlines in form of the milestones.
A typical problem, pointed out by many of the interviewed subjects, is that a lot of actors are utilizing the slack in the plans completely, i.e. never starts work until they really have to start to reach the deadline. This leads to that the project decreases its possibilities to catch up for unforeseen problems.
Another aspect pointed out is the meeting-procedures: How often should the different meetings be held, who should participate and how should the meetings be structured. This could be the reason why some claims that many decisions are taken too late and that they often to fuzzy.
3.4 Solution and Recommendation : Strategy for Construction JIT
The desire of JIT is elimination of physical buffers (materials or time) between production processes, and the achievement of one piece flow within processes. Ohno successfully eliminates such in-process inventories because production scheduling provided sufficiently stable coordination of flows compared to unstable of construction scheduling. Therefore, we cannot simplify eliminate the physical buffers because the first thing before come to this step is attacking the causes and uncertainty in construction. Even though manufacturing and construction share the same ultimate objective of reducing variation and waste, their strategies for achieving that objective must be different.
The strategy recommended by Glenn and Gregory in implementation of JIT in construction are:
1) Better Location and Sizing of Schedule Buffers
• Will require developing better assessments of project uncertainty and determining the quantitative relationship between buffers and the uncertainty they are intended to buffer. It will also require experimentation with relocating schedule buffers, to test the principle of locating buffers just behind processes that are the source of flow variation.
2) Place Plan Buffers and Make Ready Processes Ahead of Each Production Process
the Last Planner (LP) initiative, has been described in some detail in previous papers . Although it has been experimentally tested in both the United States and South America (Venezuela), it may be helpful to consider it as a research hypothesis.
Hypothesis: Production can be shielded from upstream uncertainty through planning.
Benefits of the Research: The Last Planner method of detailed production planning shields production from upstream uncertainty thus improving productivity, revealing sources of uncertainty and variation, releasing resources for further improving performance "behind the shield," and providing a highly predictable near-term work flow to downstream processes.
Methodology:
• Solicit engineering and construction projects from industry.
• Evaluate the crew/squad level planning systems of each
• Help participants conform their systems to the Last Planner Model.
• Develop measurements of comparative productivity
• Before and after LP
• Between LP and non-LP
• Collect measurement data; i.e. percent planned assignments completed, planned productivity, and actual productivity.
• Analyze measurement data and test hypothesis Characteristics of the Last Planner Method:
• Written weekly work plans for each front line supervisor and work group.
• Assignments drawn from a backlog of workable assignments created by screening for constraints and by acquiring necessary resources.
• Assignments expressed at the level of detail necessary for screening -Weekly work plans sized to target productivity.
• Front line supervisors participate in the selection and sizing of assignments, provide reasons why planned work was not done, -Craft superintendents/Discipline supervisors see that others act on reasons beyond the reach of the craft or discipline.
3) Progressively Replace Schedule Buffers with Plan Buffers The long term goal of replacing schedule buffers with plan buffers. Hypothesis: Work flow variation can be reduced.
Benefits of the Research:
1) Project duration can be reduced by reducing the buffers between EPC functions, and buffer sizes can be reduced if work flow variation can be reduced. 2) If work flow can be made more predictable, labor and other resources can be better matched to work flow, thus improving productivity.
Methodology:
Phase I: Identify and analyze examples of successful efforts (tools and techniques) to increase the predictability of work flow.
Phase II: Test tools and techniques in experiments sponsored by industry members.
Examples of Tools and Techniques:
• Developing more accurate assessments of project uncertainty.
• Adjusting schedules using work packages and milestone screening. station, until limits of predictability are met. Act on constraints to push back limits.
• Buying information to extend the accuracy and range of forecast deliveries.
• Producing more advance warning of changes in design, -Integrating supplier and customer schedules at the item (e.g. isometric)
3.5 Conclusion
In order to achieve advancement in construction JIT, it is permitted to develop new tools and techniques by demonstrate techniques and industry research to test the theories. As mentioned earlier, the construction and manufacturing are different types of production. However, the application of JIT is still applicable to construction in which physical buffers may ultimately be replaced by better managing uncertainty and eliminating the causes of flow variation. As the implementation of plan buffers propagates certainty throughout projects, productivity will improve from better matching labor to work flow, and project durations will shorten as physical buffers shrink with the flow variation they are designed to absorb.
For instance, In Denmark, Bertelsen (1995) reported a 10 per cent increase in productivity in the first phase of a social housing project that experimented with the use of the JIT philosophy in building logistics; the second phase of the project resulted in an average 7per cent increase in productivity. It was also noted that savings were not evenly distributed among the participants and that the project itself was not delivered at a lower price.
The rationale for this study is to see application of Just in Time (JIT) in construction industry. In this context, the JIT philosophy appears to hold tremendous potentials for improving the movement of construction site.
The space constraints for storage and the traffic congestion at the worksite can then be alleviated.
CHAPTER 4
JIT : AN OVERVIEW OF IBS
4.0 JIT and IBSThe term ‘Just-In-Time’ (JIT), used for instance to describe the delivery of materials to a construction site, suggests that materials will be brought to their location for final installation and be installed immediately upon arrival without incurring any delay due to storage in a laydown or staging area. JIT is a concept developed by the Japanese who created the Toyota Production System, later translated into English as the lean production system. The ultimate objective of JIT production is to supply the right materials at the right time and in the right amount at every step in the process.
Thus, IBS is one example of JIT in construction. Rahman and Omar (2006) defined IBS as a construction system that is built using pre-fabricated components. The manufacturing of the components is systematically done using machine, formworks and other forms of mechanical equipment.
IBS is defined as products, systems and techniques used in making construction less labour-oriented, faster as well as quality controlled. It generally involves prefabricated products, factory manufactured elements that transported to the construction sites and erected. (Shaari, Bulletin Ingénieur, 2003)
According to Abraham Warszawski (1999), IBS is defined as a set of element or component which is inter-related towards helping the implementation of construction works activities. He also expounded that an industrialisation process is an investment in equipment, facilities, and technology with the objective of maximising production output, minimising labour resource, and improving quality while a building system is defined as a set of interconnected element that joint together to enable the designated performance of a building.
4.1 Classification of IBS
According to Badir- Razali, generally, there are four types of building systems currently available in Malaysia’s building system classification (Badir et al. 1998), namely conventional, cast in-situ, prefabricated and composite building systems. Each building system is represented by its respective construction method which is further characterised by its construction technology, functional and geometrical configuration.
Nonetheless, according to CIDB (2003), the structural aspects of IBS of the systems, divided into five major types as follows:
1. Precast Concrete Framing, Panel and Box Systems
Precast columns, beams, slabs, 3-D components (balconies, staircases, toilets, lift chambers), permanent concrete formwork, etc;
Precast concrete wall 2. Steel Formwork Systems
Tunnel forms, beams and columns molding forms, permanent steel formworks (metal decks, etc;
3. Steel Framing Systems
Steel beams and columns, portal frames, roof trusses, etc;
Steel roof trusses
4. Prefabricated Timber Framing Systems Timber frames, roof trusses, etc;
5. Block Work Systems
Interlocking concrete masonry units (CMU), lightweight concrete blocks, etc.
Lightweight concrete blocks are used for wall construction
The pre-cast concrete components are among the most common prefabricated elements that are available both locally and abroad. The pre-cast concrete elements are concrete products that are manufactured and cured in a plant environment and then transported to a job site for installation. The elements are columns, beams, slabs, walls, 3-D elements (balconies, staircase, toilets, and lift chambers), permanent concrete formwork and etc.
The steel formwork is prefabricated in the factory and then installed on site. However the steel reinforcement and services conduit are installed on site before the steel formwork are installed. The installation of this formwork is easy by using simple bracing system. Then concrete is poured into the formwork and after seven days, the formwork can be removed and there is some system whereby the formwork served as a part of the structure itself after concreting. The steel formwork systems are used in tunnel forms, beams, column moulding forms and permanent steel formworks.
The elements of steel framing system are rolled into the specific sizes and then the elements are fabricated that involves cutting, drilling, shot blasting, welding and painting. Fabricated elements are sent to the construction site to be then erected whereby welding and the tightening of bolts at joints are conducted. The elements include steel beams and columns, portal frames and roof trusses.
The prefabricated timber framing system is normally used in the conventional roof truss and timber frames. The timber is prefabricated by joining the members of the truss by using steel plate. It is important that all members are treated with the anti pest chemical. Then, the installation is done on site by connecting the prefabricated roof truss to the reinforcement of the roof beams.
The elements of block work system include interlocking concrete masonry units (CMU) and lightweight concrete blocks.
The elements are fabricated and cured in the factory. The elements are normally used as bricks in structures and interlocking concrete block pavement. 3.2 Value Stream Mapping
Koskela (1992) pointed out that architects, engineers, and construction practitioners have for the longest time focused on conversion activities and overlooked issues of flow. Flow is important because work or materials that do not flow sit idle in inventory, tying up money (including the procurement cost of ingredients plus labor and machine time to bring them to the stage of completion they are in) as well as space. They stand the risk of being damaged or becoming obsolete due to design changes or market competition. Inventory means product waits: its cycle time increases, that is, it takes longer for the product to traverse all production steps it needs to go through before reaching its customer. As a result, project durations are larger than they would have been had flow not been inhibited.
Most tools used today by practitioners who manage construction, such as those fordesign, planning, scheduling, and costing, do not acknowledge flow: they do not explicitly capture changes of resource characteristics over time. Process modeling tools for discrete event simulation are an important exception and warrant more attention by the lean construction community. Such models can incorporate input regarding individuallycharacterized components, uncertainties of numerous kinds, and sequencing rules (e.g., Tommelein 1997) and then produce output data regarding buffer sizes, cycle times, idle times, production rates, etc. The symbols commonly used to depict process models for construction, however, have yet to distinguish how processes are being managed, for instance, whether or not a JIT system has been implemented. Practitioners in manufacturing, working for Toyota and then later for other companies ‘going lean’ developed their own pictorial language to help focus attention on what matters in their transition.
We borrowed such symbols from Rother and Shook (1998) and used them to map structural steel supply chains. Boxes denote value-adding processes or tasks, such as ordering raw materials, fabricating steel, and transporting shipments to a site. A triangle denotes work in progress or inventory. It represents an accumulation of product (materials or information) possibly of unlimited amount and for an indeterminate duration. An inverted triangle is an order to batch. Kanban (introduced in Figure 1) denote orders to withdraw
or produce product, in order to deplete or replenish a supermarket. A supermarket, represented by , refers to controlled inventory in terms of how much material is kept on hand and how replenishment takes place. The FIFO symbol denotes the first-in-first out release of resources output by a task. The circular arrow denotes a physical pull of materials from a supermarket. It differs from the withdrawal kanban in that it pertains to the amount of product needed at the time of the withdrawal and not necessarily a predetermined