JUST IN TIME(JIT)

A highly coordinated processing system in which goods move through the system , and services are performed , just as they needed

LEAN OPERATIONA highly coordinated system that uses minimal resources and produces high-quality goods or services.

TOYOTA APPROACH

Lean operations began as manufacturing in the mid-1900s. It was developed by the japanese automobile manufacturer, TOYOTA.

MUDAWaste and inefficiency.

KANBANA manual system that signals the need for parts or materials

PULL SYSTEMReplacing material or parts based on demand

HEIJUNKAVariation in production volume lead to waste. It means workload levelling.

KAIZENContinuous improvement of the system.

JIDOKAQuality at the source . Each worker is expected to perform ongoing quality assurance.

POKA-YOKESafeguards built into a process to reduce the possibility of committing an error.

TEAM CONCEPTUse small teams of workers for process improvement.

OBJECTIVES OF JIT

1.Eliminate disruptions

2.Make the system flexible

3.Reduce setup times and lead times

4.Minimize inventory

5.Eliminate waste

WASTE

Waste is anything that does not add value from the customer point of view

TYPES OF WASTE

Overproduction Queues Transportation Inventory Motion Overprocessing Defective products

BUILDING BLOCKS

PRODUCT DESIGN

Four elements of product design are important for JIT-

1.Standard parts.

2.Modular design.

3.Highly capable production systems with quality built in.

4.Concurrent engineering.

STANDARD PARTS:The use of STANDARD PARTS means that workers have fewer parts to dealt with, and training times, and costs are reduced.

MODULAR DESIGN:Modules are clusters of parts treated as a single unit. This greatly reduces the number of parts to deal with.

HIGHLY CAPABLE PRODUCTION SYSTEMS WITH QUALITY BUILT IN:Quality must be embedded in goods and processes.

ENGINEERING:Concurrent engineering practices can reduce these disruptions.

PRODUCT DESIGN

PROCESS DESIGN

Seven elements of product design are important for JIT-

1. Small lot sizes

2. Setup time reduction

3. Manufacturing cells

4. Quality improvement

5. Production flexibility

6. A balanced system

7. Little inventory storage

8. Fall-safe methods

PROCESS DESIGN

SMALL LOT SIZES:In the JIT philosophy, the ideal lot size is one unit.Small lots moving through the system reduce the in-process inventory.It reduces the carrying cost , space requirements.Small lots permit greater flexibility in scheduling.

SETUP TIME REDUCTION:Small lots and changing product mixes require quick setup.Long setup times require holding more inventory than with short setup times.

*Shiegeo Shingo made a significant contribution to lean operation.SMED(Single-minute exchange of die)This system is for reducing changeover time.

MANUFACTURING CELLS:Multiple manufacturing cellsHighly specialized and efficient production centreIt reduced changeover times, high utilization of equipment.

QUALITY IMPROVEMENT:Finding and eliminating the causes of problems to improve the quality.Uses of Autonomation can reduce the defects and improve the quality.

PRODUCTION FLEXIBILITY:Reduce the bottlenecks to improve the production flexibility.

A BALANCED SYSTEM:Distributing the workload evenly among workstations.It helps to achieve a rapid flow of work through the system.Time needed for each workstation must be equal or less to as the Takt time.*Takt time:The cycle time needed to match customer demand for final product.

INVENTORY STORAGE:JIT systems are designed to minimize the Inventory storage.Inventory hides the problems.

FAIL-SAFE METHODS:Building safe-guards to reduce or eliminate the potential for errors during a process.*Poka-yoke

PERSONNEL/ORGANIZATIONAL ELEMENTS

There are five elements of personnel and organization that are important for JIT systems-

1. Workers are assets.

2. Cross-trained workers

3. Continuous improvement.

4. Cost accounting.

5. Leadership/project management.

WORKERS ARE ASSETS:Well trained and motivated workers are the heart of JIT systems.

CROSS-TRAINED WORKERS:Workers are cross-trained to perform several parts of a process and operate a variety of machines.

CONTINUOUS IMPROVEMENT:JIT systems have greater responsibility for quality .

COST ACCOUNTING:Another feature of some JIT systems is the method of allocating overhead.

LEADERSHIP/PROJECT MANAGEMENT:Managers are expected to be leaders and facilitators , not order givers.

MANUFACTURING PLANING AND CONTROL

Seven elements of manufacturing planning and control are particularly important for JIT systems-

1.Level loading

2.Pull system

3.Visual systems

4.Limited work -in-progress

5.Close vendor relationship

6.Reduced transaction processing

7.Preventive maintenance and housekeeping.