Just-in-time delivery systems are a very important aspect of lean production, which is focused on reducing waste in production operations, and just-in-time reduces the waste of an excessive amount of inventory. Lean production will be defined as “an adaptation of production within which workers and work cells are made more flexible and efficient by adopting methods that reduce waste altogether forms.
Its origins are traced to the Toyota Production System at Toyota Motors in Japan starting within the 1950s. Although its initial applications were within the automotive industry, the target of minimizing waste is vital altogether industries. In effect, lean production means accomplishing more work with fewer resources by eliminating waste in manufacturing operations. Activities in manufacturing are often classified into three categories: (1) actual work activities that add value like processing steps that alter the merchandise in an exceedingly positive way, (2) auxiliary work activities that support the actual work like loading and unloading a production machine, and (3) wasteful activities that don’t add value and don’t support the value-adding activities. If these wasteful activities were omitted, the merchandise wouldn’t be adversely affected.
Seven types of waste in manufacturing were identified within the Toyota Production System: (1) production of defective parts, (2) production of more parts than needed, (3) excessive inventories, (4) unnecessary processing steps, (5) unnecessary movement of workers, (6) unnecessary handling and transport of materials, and (7) workers waiting. the varied systems and procedures developed at Toyota were designed to cut back or eliminate these seven sorts of waste.
The principal components of the Toyota Production System were just-in-time delivery, autonomation and worker involvement.
Autonomation refers to the look of production machines that operate autonomously ciao as they function the way they’re purported to. If and after they do not operate the way they ought to, they’re designed to prevent. Circumstances that would trigger a machine to prevent include producing defective parts and producing more than the quantity of parts needed. Other aspects of autonomation include error prevention and high reliability.
Stop the method The underlying principle is that when something goes wrong, the process should be stopped so corrective action may be taken. This is applicable to both automatic machines and operated by hand processes. Production machines within the Toyota Production System are designed with sensors and automatic stop devices that are activated when a defective unit is produced or when the desired number of units are made. Accordingly, when a machine stops, it draws attention, either to form adjustments to the method to avoid future defects, or to vary over
the process for the subsequent batch of parts. the choice to autonomation is that the machine would still make bad parts, or it’d make too many parts.
The notion of “stop the process” also can be applied to manual production, such as the final production line in an automobile plant. Workers on the road are empowered to prevent the road once they discover a controversy like a high quality defect. they are doing this by means of pull cords that are located along the road. Downtime on an assembly line draws attention and is expensive to the plant. Significant efforts are made to repair the problem that caused the road to be stopped. Defective components must be avoided by pursuing the goal of zero defects.
Error Prevention A second objective of autonomation is preventing mistakes. Mistakes in manufacturing include using the incorrect tool, starting a process with the
wrong material, omitting a processing step part, neglecting to feature a component in an assembly operation, incorrectly locating an element in an exceedingly fixture, and incorrectly locating the fixture on the machine. To avoid these and other forms of mistakes, devices are designed to detect abnormal conditions during a given operation. Examples include instruments to detect overweight parts, counting devices to work out whether the right number of spot welds has been made, and sensors to work out whether part has been properly located in a very fixture. When the device encounters a slip, it’s designed to retort by stopping the method or providing an audible or visible alert that a mistake has occurred.
Total Productive Maintenance Just-in-time delivery requires production equipment that’s highly reliable. When a production machine breaks down, it disrupts the delivery of parts to the downstream workstation, forcing that machine to be idle. JIT doesn’t provide for inventory buffers to stay production going when breakdowns occur. Total Productive Maintenance (TPM) may be a program that aims to attenuate production losses because of machine failures, malfunctions, and poor utilization. One of the elements of the program is to carry workers who operate equipment liable for routine tasks like inspecting, cleaning, and lubricating their machines. In some cases, they also make minor repairs on their equipment.
Three categories of maintenance are performed on a plant’s equipment by trained specialists: (1) emergency maintenance, which involves the immediate repair of a machine that has broken down; (2) preventive maintenance, which consists of routine repairs designed to avoid or minimize breakdowns; and (3) predictive maintenance, which attempts to anticipate machine malfunctions by monitoring the equipment for signs of problems and abnormal behavior. Emergency maintenance is undesirable because it means the machine is out of action and production has ceased. Preventive maintenance is often scheduled during hours when the machine isn’t running, as an example, during the third shift in a very plant that runs two shifts. Predictive maintenance is performed while the machine is running. A TPM program integrates preventive maintenance and predictive maintenance so as to avoid emergency maintenance.