The main idea of JIT (Just in Time) production or lean one is its emphasis to eliminate waste from the manufacturing process. Lean production is all about doing more with less. This is in a shorter time, minimal inventory, space, labour, and other resources. Batch production, on the other hand, refers to the one on a mass scale. In batch manufacturing items are not produced based on their demand. Batch production requires companies to stock on manufactured products or even inventory. When Toyota introduced JIT, most manufacturers kept large inventories for use when they required them. Taiichi Ohno of Toyota found out that the just in time system lessens lead time on all orders and reduced production costs. The system rapidly spread as many companies adopted it. The JIT process was designed to make sure that a part would arrive exactly at the time when it would be used. This system eliminated the need to keep inventory. JIT production, when properly implemented in a company has the potential to strengthen the companies’ competitiveness by waste reduction, improvement in product quality and efficient production.
In mass production, manufacturing and sales cycles are two distinct and separate issues. However, in JIT production, they are closely intertwined. JIT requires that products are manufactured only based on their demand. Batch production is supply oriented while JIT production is demand oriented. The most crucial difference between the two theories for production is that JIT production considers customers. Batch production is based on forecasts of the possibility of demand. Batch production anticipates demand in the future.
Just in time production comes with the advantages of less space required for operations, reduction in wastes, and requires smaller investments. However, careful planning should be done to ensure that the risk of running out of stock is minimal.
Push and pull systems are important in understanding production lines. Push systems allow production to continue individually and independently. There is no communication among the processes bout their demand. Lack of communication in the push system can lead to overproduction. Communication is established throughout the whole process in a pull system. So, that all products are produced just in time (Cook 1996, p.375).
The use of kanbans is a way of establishing communication in the process. A Kanban is a piece of information. It is sent automatically and used in control of production. The Kanban relays information about the demand in the production process. Details may include the type and amount of inventory, and where they are to be delivered. Lead time is often compromised by two items; process failure and setup execution. To overcome process failure, total productive maintenance is employed. This system involves the identification of failure, the study of the failure and continuous improvement. Setup execution is however related to the system’s flexibility. There is an increasing demand by consumers for customized products. Many workstations are optimized to produce more than one product. Process setups must, therefore, be executed quickly. Set up time minimization is therefore necessary.
Improving efficiency in logistics has been at the core of determining business performance. The most important way has been to strategically align logistics in a way that maximizes profit. Until recently, the calculation of profitability did not include the social and environmental costs. Companies are now under increased pressure from governments and environmental organizations to reduce the environmental impact of their operations (Dues, Tan, and Lim 2012, p.4).
I once thought, Lego was just a kid’s toy, you were meant to play it as a child and that was it. Today, the Lego bricks show up in all sorts of peculiar places and the players are also unexpected too. Lego bricks have found their way to displays in museums, classrooms, and even at various places of work. The use of Lego now has extended beyond children playing with them and parents kicking the bricks as they walk in the house. The brightly coloured Lego bricks can be also seen as tools. We use tools for building, teaching, thinking and much more. If we look at Lego blocks as tools, then the possibilities are unlimited. The Lego system is built in a way that other creative materials are not. The Lego system adopts the notion that everything connects to everything else as in the Lego bricks tubes and studs. The idea of connectivity embodies a philosophy of empowering people to build creatively.
The Lego game was set up to with 4 operators, one for each stage in the production of seaplane including one inspector. The operators were responsible for assembling a particular part. The inspector checked all products for defects and recorded all the total number of products produced. Material handlers supplied each stage of the production line and the dismantlers replenished raw materials by dismantling finished products at the end of the production line. The sequence of operations was first to build the undercarriage then fuselage then wings and engines then the tail and ended with the inspection of the final product. Both JIT and batch production lines ran for 10 minutes. The Batch production line used a push system with batches of 5 products while the JIT used system used a push system with batches of 3 products. Operators in the JIT system only worked on demand.
At the end of the game, it was observed that the Batch process produced more products with the initial design. When the design changed, the batch mode produced less. The batch mode also recorded more defects while the JIT model recorded zero defects. The Lego bricks were generally disorganized. There were challenges in operators 1 and 2 finding the correct bricks to start off the seaplane with the undercarriage. I spent a lot of time sorting out bricks at this stage. Lead time is reduced in the JIT model only when the bricks were replenished in time by the dismantler. However, at the start of the process, JIT recorded a shorter lead time and less work in process.
An effective system of production requires a suitable and organized environment. It requires tools for sorting out and standardizing work environments. The use of Kanban’s by the JIT production line ensured that only the needed products were produced.
There is increasing awareness to harmonize economic and environmental interest for sustainability. Lean or JIT production is a strategy that has proved its effectiveness in the industry over a long time. More value with less environmental impact is the core feature in streamlining production processes. Companies have to rethink their strategies so that they can create more value to their products and also prevent environmental burdens to future generations. Lean thinking lays emphasis on doing more with less. However, lean methods seem not to put too much emphasis on the environmental impact of their use.
Eco-efficiency is a concept that is the key to sustainability. It seeks to provide more value with less environmental impact. Integrating the concepts of Lean and eco-efficiency have been integrated to after recognition that the growth of the human population and their activities threaten future generations and other species. Industries employing this concept capture implement the ideas of lean and sustainability in their operations. The goals achieved through, extending the durability of products, recycling, using renewable energy, reducing the number of toxic substances or decreasing toxicity levels.
The modern shipping industry provides a good example of an industry that has employed the concept of lean and now is in the process of implementing various interventions for sustainability. The distribution of goods around the world impairs local air quality, makes a significant contribution to global warming, causes accidents, oil spills, and many other hazards. Ships call in ports only when they need to. Port charges are high and delays are very costly. They also only receive bunker reserves where they are cheapest and the quantity taken is balanced by sacrificing cargo load. These are all concepts of lean. For sustainability, regulations provide that ships need to reduce their carbon footprints by installing appropriate scrubber systems. These scrubbers reduce greenhouse emissions from ships.
Economically, it is cheaper to break a ship on beaches in South Asia. Hundreds of ships are dismantled on these beaches every year. Ships are beached on these tidal mudflats. Low paid workers or even children dismantle them with very little technical expertise. Most of the workers lack basic protective equipment. A number of fatalities and injuries are recorded every year. There is also increased pollution on the shipbreaking beaches. This is a classic concept of a lean process not taking into account sustainability. It is a good economic decision to dismantle ships in this beaches but it is not sustainable. The social and environmental impacts are far too grave. The European Parliament recently adopted a regulation binding all ships that fly the flag of its member states. The Ship Recycling Regulation of 20th November 2013 requires that all ship recycling facilities comply with safety and environmental requirements. The new rules also cover the use of hazardous substances on ships. The aim is to reduce and restrict their usage. Such materials may include asbestos and ozone-depleting chemicals.