Wednesday, March 28, 2018

Just In Time - JIT


The JIT: Just-in-time (JIT) manufacturing techniques were perfected in Japan in over last few decades. From previously scattered and disconnected ideas and principles ,JIT has developed into a recognizable body of knowledge. Philosophy appears to be at the core of Japanese production management and productivity improvement. JIT is more than just a production and inventory planning and control system analogous to the well-known material requirements planning (MRP) systems. JIT pervades all aspects of the production and inventory flow process, covering not only the work-in-process (WIP) inventories (parts), but also, in the forward direction, the flow of finished goods from manufacturing to distribution centers, and, in the backward direction, the flow from suppliers, and, in Japan, from suppliers of suppliers.

In the broad sense, JIT is an approach to achieving excellence in a manufacturing company. It is a disciplined approach and strategy to achieve significant continuing improvements in performance (the overall productivity and quality, not just product quality, but in terms of the needs of the customer, and the work life of the employees), through respect for people, and elimination of all sources of waste (i.e. of all non-value adding operations and resources). JIT requires and stimulates improvement in quality and productivity of all activities, from design engineering to delivery and includes all stages 'of conversion from raw materials onward. It develops the latent capabilities of all people in the company. It improves the speed and flexibility of response to change by collapsing total throughput time, involving the total network of customers and suppliers. JIT success is measured in trends : inventory and customer service levels as going up, and defects of all kinds, costs and cycle times as being down. In the broad sense, JIT applies to all forms of manufacturing, job shop as well as mass (both process and repetitive).

In the narrow sense, JIT refers to the production and delivery of only the necessary quality parts in the right quantity, at the necessary place, just-in-time (ideally) at all stages of the material flow, from purchase through fabrication, assembly to delivery to customers. JIT seeks to achieve a "production on call" at all stages. The implication is that each operation is closely synchronized with the subsequent ones to make that possible.• It has been said in humor that while the Japanese industry produces small quantities' "just in time", Western industry produces massive quantities "just in case". The objective of JIT is to reduce inventories so that the underlying problems can be solved. Achieving just in time production and delivery is dependent on the balance between the manufacturing flexibility of the supplying work centre and the schedule stability of the using work centre and is accomplished through application of specific elements which require total employee involvement and team work. Theoretical JIT or zero inventory will never occur. However, the resolution of the underlying problems in the process of approaching JIT as an ideal will realize significant benefits.

JIT is, first, a manufacturing philosophy. JIT should not be merely viewed as a set of techniques or procedures but
rather as a mind set. Techniques alone (such as set up reduction, small group improvement activities, statistical
process control, pull system of 'production, etc.) represent a shallow understanding of JIT. JIT is not something one does as much as the way a company approaches all the things it is already doing.