BENEFICIOS DE JUST IN TIME SYSTEM

Philosophy of JIT is simple: inventory is waste. JIT inventory systems expose hidden causes of inventory keeping, and are therefore not a simple solution for a company to adopt. The company must follow an array of new methods to manage the consequences of the change. The ideas in this way of working come from many different disciplines including statistics, industrial engineering, production management, and behavioral science. The JIT inventory philosophy defines how inventory is viewed and how it relates to management.

Inventory is seen as incurring costs, or waste, instead of adding and storing value, contrary to traditional accounting. This does not mean to say JIT is implemented without an awareness that removing inventory exposes pre-existing manufacturing issues. This way of working encourages businesses to eliminate inventory that does not compensate for manufacturing process issues, and to constantly improve those processes to require less inventory. Secondly, allowing any stock habituates management to stock keeping. Management may be tempted to keep stock to hide production problems. These problems include backups at work centers, machine reliability, process variability, lack of flexibility of employees and equipment, and inadequate capacity.

In short, the just-in-time inventory system focus is having “the right material, at the right time, at the right place, and in the exact amount”-Ryan Grabosky, without the safety net of inventory. The JIT system has broad implications for implementers.
JIT Implementation Design
Based on a diagram modeled after the one used by Hewlett-Packard’s Boise plant to accomplish its JIT program.

1) F Design Flow Process
- F Redesign/relayout for flow
- L Reduce lot sizes
- O Link operations
- W Balance workstation capacity
- M Preventive maintenance
- S Reduce setup Times
2) Q Total Quality Control
- C worker compliance
- I Automatic inspection
- M quality measures
- M fail-safe methods
- W Worker participation


3) S Stabilize Schedule
- S Level schedule
- W Establish freeze windows
- UC Underutilize Capacity
4) K Kanban Pull System
- D Demand pull
- B Backflush
- L Reduce lot sizes
5) V Work with Vendors
- L Reduce lead time
- D Frequent deliveries
- U Project usage requirements
- Q Quality expectations
6) I Further Reduce Inventory in Other Areas
- S Stores
- T Transit
- C Implement carrousel to reduce motion waste
- C Implement conveyor belts to reduce motion waste

7) P Improve Product Design
- P Standard production configuration
- P Standardize and reduce the number of parts
- P Process design with product design
- Q Quality expectations

Main benefits of JIT include:
• Reduced setup time. Cutting setup time allows the company to reduce or eliminate inventory for "changeover" time. The tool used here is SMED (single-minute exchange of dies).
• The flow of goods from warehouse to shelves improves. Small or individual piece lot sizes reduce lot delay inventories, which simplifies inventory flow and its management.
• Employees with multiple skills are used more efficiently. Having employees trained to work on different parts of the process allows companies to move workers where they are needed.
• Production scheduling and work hour consistency synchronized with demand. If there is no demand for a product at the time, it is not made. This saves the company money, either by not having to pay workers overtime or by having them focus on other work or participate in training.
• Increased emphasis on supplier relationships. A company without inventory does not want a supply system problem that creates a part shortage. This makes supplier relationships extremely important.
• Supplies come in at regular intervals throughout the production day. Supply is synchronized with production demand and the optimal amount of inventory is on hand at any time. When parts move directly from the truck to the point of assembly, the need for storage facilities is reduced.