Just In Time ….

Just in Time Philosophy Salient features  The notion of waste in any operating system  JIT as a philosophy of elimination of waste As a deliberate and a systematic attempt On a continuous basis

Just In Time Manufacturing Water Flow Analogy Unrealistic Variable DefectivePoor schedulesLackProcessingMaterial Quality of Times training MachineInadequate Bottleneck BreakdownInformation Behavioural/Managerial constraints

JIT Philosophy Core Logic Source: Schonberger, R..J. (1982), “Japanese Manufacturing Techniques: Nine hidden lessons in simplicity”, Free Press, pp 26.

JIT Philosophy Overall Impact

JIT Manufacturing Basic Elements  It originally referred to the production of goods to meet customer demand exactly, in time, quality and quantity, whether the `customer' is the final purchaser of the product or another process further along the production line.  It has now come to mean producing with minimum waste. "Waste" is taken in its most general sense and includes time and resources as well as materials.

 Just-in-time' is a management philosophy and not a technique. Elements of JIT include:  Continuous improvement.  Attacking fundamental problems - anything that does not add value to the product.  Striving for simplicity - simpler systems may be easier to understand, easier to manage and less likely to go wrong.  Quality control at source - each worker is responsible for the quality of their own output.

Poka-yoke - `foolproof' tools, methods, jigs etc. prevent mistakes Preventative maintenance, Total productive maintenance - ensuring machinery and equipment functions perfectly when it is required, and continually improving it. Good housekeeping - workplace cleanliness and organisation. Set-up time reduction - increases flexibility and allows smaller batches. Ideal batch size is 1item. Multi-process handling - a multi-skilled workforce has greater productivity, flexibility and job satisfaction.

Kanbans - simple tools to `pull' products and components through the process. Jidoka (Autonomation) - providing machines with the autonomous capability to use judgement, so workers can do more useful things than standing watching them work. Andon (trouble lights) - to signal problems to initiate corrective action.

Eliminating waste. There are seven types of waste: waste from overproduction. waste of waiting time. transportation waste. processing waste. inventory waste. waste of motion. waste from product defects.

14 Lean Manufacturing Eliminating waste. There are seven types of waste:

PUSH Scheduling

PULL Scheduling

PUSH – PULL Impact on the system

Just in Time Manufacturing  JIT systems have an unambiguous definition of what constitutes waste in the system.  The philosophy of Just in Time system is one of continuous waste elimination.  Contrary to the traditional thinking, the inventory in a JIT system is deliberately removed to expose hidden problems.  These problems are solved resulting in fewer inventory and waste in the system and greater productivity.  Implementation of JIT requires that the manufacturing architecture is converted into a chain of internal customers.  Lot size reduction and use of standard containers are other elements of a JIT system.

Just in Time Manufacturing  Production Planning and control in JIT systems is achieved through the use of Kanban  Kanban enables waste elimination from the system by preventing overproduction and exposing problems in processes.  JIT systems utilise a Pull type scheduling  Pull type scheduling are very effective in providing visible control of the processes and bringing the problems to the surface rapidly.

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