Just in time production (JIT): the other big pilar…
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 “Muda” ; variation “Mura” & Overburden “Muri” .
Waste ,is taken in its most general sense and includes time and resources as well as materials. Elements of JIT include:
• Continuous improvement.
◦ Attacking fundamental problems – anything that does not add value to the product.
◦ Devising systems to identify problems.
◦ Striving for simplicity – simpler systems may be easier to understand, easier to manage and less likely to go wrong.
◦ A product oriented layout – produces less time spent moving of materials and parts.
◦ 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.
• Eliminating waste. There are 7 types of waste:
◦ waste from overproduction.
◦ waste of waiting time.
◦ transportation waste.
◦ processing waste.
◦ inventory waste.
◦ waste of motion.
◦ waste from product defects.
• Eliminating variation. There are 3 types of variation:
◦ Variation from Process.
◦ Variation from Material.
◦ Variation from Information.
• Eliminating Overburden. There are 3 types of Overburden:
◦ Overburden of Machines.
◦ Overburden of people
◦ Overburden of system
• 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.
• Levelled / mixed production – to smooth the flow of products through the factory.
• 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.
Hence we can see that to have a Total JIT manufacturing system, a company-wide commitment, proper materials, quality, people and equipments must always be made available when needed. In addition; the policies and procedures developed for an internal JIT structure should also be extended into the company’s supplier and customer base to establish the identification of duplication of effort and performance feedback review to continuously reduced wastage and improve quality. By integrating the production process; the supplier, manufacturers and customers become an extension of the manufacturing production process instead of independently isolated processes where in fact in clear sense these three sets of manufacturing stages are inter-related and dependent on one another. Once functioning as individual stages and operating accordingly in isolated perspective; the suppliers, manufacturers and customers can no longer choose to operate in ignorance. The rules of productivity standards have changed to shape the economy and the markets today; every company must be receptive to changes and be dynamically responsive to demand. In general, it can be said that there is no such thing as a KEY in achieving a JIT success; only a LADDER; where a series of continuous steps of dedication in doing the job right every time is all it takes.