JUST-IN-TIME(J-I-T) J-I-T is an approach that seeks to eliminates all sources of waste in production activities by providing theright part at right place at the right time
Challenges of Manufacturing Organization• Quality of Products• Cost of Products• Speed of fulfilling Customers Orders
Back drop of J-I-T• During 1970s & 1980s JAPAN became an International Economic Power• In Automotive and Electronics Industry JAPAN became leader in World Market by setting product quality and cost• This success is attributed to Japanese development and application of J-I-T production system
Primary Elements of J-I-T• Required Inventory when needed• Quality to Zero defects• Reduced lead time by reducing set-up time• To incrementally revise the operations themselves• To accomplish the production at minimum cost
Classification of J-I-T J-I-T Romantic Pragmatic J-I-T J-I-T
Lean Production & J-I-T• Lean Production has its roots in Toyota Automobiles Co, Japan where wastes are avoided at all costs• The waste in time caused by having to repair faulty products• The waste of Investment in keeping with high Inventories• The waste of having Idle Workers
Elements of Lean Production• To Consider the Organization in terms of Supply Chain of Value streams from suppliers of raw materials to final Customers• To produce products & perfect quality• To have continuous quality improvement
Elements of Lean Production (Contd)• To organize the operation by Product or Cellular manufacturing rather than functional or process layout• To operate the facility in J-I-T mode• J-I-T is a key element in lean production
CONCEPTS OF J-I-T• Elimination of waste and Variability• Pull versus Push System• Manufacturing cycle time
Waste Reduction• Anything that does not add value is waste in the production• Products being stored, inspected or delayed, products awaiting in queue and defective products do not add value and are 100% waste• J-I-T speeds up manufacturing cycle reduces WIP and releases capital tied up in Inventory holding.
Variability Reduction• J-I-T material movement demands reduction in variability by both internal and external factors• Variability is any deviation of actual process from the optimum process• Inventory holding hides variability• Variability is caused by tolerating wastes or by poor management.
Reasons for occurrence of Variability• Employees, machines and suppliers produce units that do not conform to standards, are late and are not proper quantity.• Engineering drawings and specifications are inaccurate• Production personnel try to produce before the drawings and specifications are finalized• Customer demands are unknown• J-I-T philosophy of continuous improvement removes variability
Pull versus Push System• The concept behind J-I-T is Pull System• In J-I-T Concept materials produced or supplied only when requested and moved to where it is needed• Pull System uses signals to request production and delivery from upstream sections to the station that has production capacity available
Pull versus Push System(Contd)• Push System pushes materials into downstream workstation regardless of their timeliness or availability of resources to perform the work
Objectives of J-I-T Manufacturing• Produce only the products that Customers want• Produce products only as quickly as customers want to use them• Produce products with perfect quality• Produce in minimum possible lead time
Objectives of J-I-T Manufacturing(Contd)• Produce products with features that customers want and no others• Produce with no waste of labour,materials or equipment, designate a purpose for every movement to leave Zero idle inventory• Produce with methods that reinforce the occupational development of workers.
Activities of J-I-T Manufacturing• Inventory Reduction• Quality Improvement• Lead time Reduction• Vendor Control/Performance Improvement• Continuous Improvement• Total Preventive Maintenance• Strategic Gain
Characteristics of J-I-T System• Pull method of material flow• Constantly high Quality• Small lot sizes• Uniform workstation loads• Standardized components and work Methods• Close Supplier ties• Flexible Workforce
Characteristics of J-I-T System(Contd)• Line flow strategy• Automated Production• Total preventive maintenance
Pull method of Material Flow• Uses signals to request production and delivery from stations upstream to the station that has production capacity available• By pulling materials through the system in very small lots just as it is needed, the cushion of inventory that hides problems is removed• This reduces investment locked in inventory and manufacturing Cycle time.
Consistent High Quality• J-I-T System seeks to eliminate scrap and rework• J-I-T System Controls Quality at Source• Workers act as their own Inspector
Small Lot Sizes• Reduces lead time• Reduces WIP• Help achieve uniform workload
J-I-T Purchasing• Supplier development and supplier relation undergo fundamental changes• Suppliers Customers maintain co- operative relation• Supplier network is referred to as co- producer• Purchasing department develop lomg term relationship with few suppliers only instead of too many suppliers
J-I-T Purchasing(Contd)• Apart from price quality, delivery schedules, mutual trust and co-operation forms the basis of supplier selection• Suppliers are encouraged to extend J-I-T methods to their suppliers• To make lead time shorter suppliers are developed near the Customer or clustered toghether at some distance
J-I-T Purchasing(Contd)• Shipments are delivered directly to customer’s production line usually through suppliers own vehicle• Parts are delivered in small, standard size containers without much paper work• Delivered materials are of perfect quality
Pre-requisites for J-I-T Manufacturing• Stabilized production schedules• Make the factories focused• Increase production characteristics of manufacturing work centers• Improve product quality• Cross train workers for multi skilling• Reduce equipment breakdown through preventive maintenance• Develop long time supplier relationship
Elements of J-I-T Manufacturing Systems• Eliminating wastes• Enforced problem solving• Continuous Improvement• Involvement of people• Total Quality Management• Parallel processing
Major Tools & Techniques of J-I-T Manufacturing• Kanban System or Pull Scheduling• Set up Reduction(SMED)• Lean Production• Poka-yoke(Fool proofing)• Quality at the source• Standardization & Simplification• Supplier Parternership• Reduced transaction processing• Kaizen( Continuous improvement)
Kanban System or Pull Scheduling• Kanban is a Japanese word meaning CARD• Kanban communicates within the workshop• To build only what Customers demand is Pull Scheduling
Set-up time reduction• Evolve towards lot size of one unit• Run every part every day• Make the first piece right every time• Keep up set up times to 10 minutes• Process flow analysis of set-up times• Housekeeping• Practiced Teamwork
Problems in Implementing J-I-T• J-I-T is primarily applicable to repetitive production situation• J-I-T demands discipline• J-I-T is based on co-operation and trust of people,worker,managers,supplier,custome r and so on.• Toyota Company took 20 years to develop J-I-T
Problems in Implementing J-I- T(Contd)• J-I-T implementation is expensive when training costs, preventive maintenance costs and consulting costs are considered• Many companies equate J-I-T with cutting inventory which is dangerous• J-I-T Environment often places additional stress on shop workers