POM Ch-24

PRODUCTION AND OPERATIONS

MANAGEMENT

Chapter 24JUST-IN-TIME

SYSTEMS

Himalaya Publishing HouseProduction and Operations ManagementBy K. Aswathappa & K. Shridhara Bhat

Chapter 24Just-in-Time Systems

What is a “Just-in-time System”?

• “Just-in-time”: A philosophy of manufacturing based on planned elimination of all waste and continuous improvement of productivity.



Concepts of JIT

The three fundamental concepts of JIT are :

1. Elimination of waste and variability

2. “Pull” versus “Push” system and

3. Manufacturing cycle time (or “throughput” time).



Overview of JIT manufacturing

Inventory reduction Quality improvement Lead time reduction Lead time reduction Continuous Improvement Total Preventive Maintenance Strategic Gain



Characteristics of Just-in-Time System

1. Pull method of material flow2. Constantly high quality3. Mall lot sizes4. Uniform workstation loads5. Standardised components and work methods6. Close supplier ties7. Flexible workforce8. Line flow strategy9. Automated production10. Preventive maintenance



JIT Manufacturing Versus JIT Purchasing

JIT manufacturing: An Organisation- wide approach to produce output with in the minimum possible lead time and at the lowest possible total cost by continuously identifying and eliminating all forms of waste and variance.

JIT purchasing: Same pull type approach used in JIT manufacturing applied to purchasing shipments of parts and components from suppliers.



Pre-requisites for JIT Manufacturing

1. Stabilise production schedules.2. Make the factories focussed.3. Increase production characteristics of manufacturing work

centers.4. Improve product quality.5. Cross-train workers so that they are multi-skilled and

competent in several jobs.6. Reduce equipment break downs through preventive

maintenance.7. Develop long-term supplier relationships that avoid

interruptions in material flows.



Elements of JIT Manufacturing System

1. Eliminate waste

2. Enforced problem solving

3. Continuous improvement

4. Involvement of people

5. TQM

6. Parallel processing



Benefits of JIT System

1. Low inventory levels

2. Shorter production cycle time

3. Improved product quality

4. Reduced WIP Inventory

5. Better labour utilisation.



Major Tools and Techniques of JIT Manufacturing

Shop-floor JIT or little JIT has nine tactical tools.

The tactical tools of little JIT are :i. Kanban system or Pull scheduling

ii. Set up reduction (SMED)

iii. Lean production

iv. Poka- Yoke (Fool proofing)

v. Quality at the source



vi. Standardisation and simplification

vii. Supplier partnerships

viii. Reduced transaction processing and

ix. Kaizen (continuous improvement).

Kanban system:

A physical control system consisting of cards and containers. The system is used to signal the need for more parts and to ensure that those parts are produced in time to support subsequent fabrication or assembly.



Benefits of Kanban

Kanban systems have resulted in significant benefits :1. Reduced inventory level

2. Less confusion over sequence of activities

3. Less obsolescence of inventories while in storage

4. Smaller floor space requirements for storing inventory



The focus of JIT systems is on improving the process, therefore, some of the JIT concepts useful for the manufacturer are also useful to service providers. These concepts include the following :

1. Consistently high quality2. Uniform facility loads3. Standardised work methods4. Close supplier ties5. Flexible workforce 6. Automation7. Preventive maintenance8. Pull method of material flow9. Line flow strategy

POM Ch-24

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Transcript of POM Ch-24