Transcript Just-In-Time - University of San Francisco

Just-In-Time
“Eliminate Waste”
Flexible Resources
Multifunctional workers
– Operate more than one machine
General-purpose machines
– Machines that were not highly specialized
Cellular Layouts
Manufacturing cells
– Often U-shaped
– Work flows through cell in one direction and
experiences little waiting
Pull System
Coordinating production and delivery of
materials and parts
Traditionally, inventory has been used as a
cushion against lapses in coordination and
inventory can be huge
Pull system observed at US supermarkets
– Marina Safeway example
Pull System
Do not order more product than can be used
– (or items that can be sold)
Reversal of normal ‘push’ system
Kanban Production Control System
Japanese word for ‘card’
Associated with fixed-quantity inventory system
Two-bin system
Kanban
Small-Lot Production
Requires less space and capital
Produces small amounts at a time
– Processes can be moved closer together
– Transport between stations is simplified
Quality problems are easier to detect
Reveals errors and bottlenecks
– HP video
Lead Time
Processing time
– Can be reduced by reducing number of items
processed and the efficiency or speed of the worker
Move time
– Can be decreased if machines are moved closer
together, method of movement simplified, routings
are standardized, or need for movement eliminated
– Con’t
Lead Time
Waiting Time
– Can be reduced through better scheduling of
materials, workers, machines and sufficient capacity
Setup Time
– Reduction of setup time is important to JIT
Quick Setups
Separate internal setup from external setup
– Internal setup requires the machine to be stopped
– External setup can be done while machine is running
Convert internal setup to external setup
– Prepare as much as possible in advance (preheating
injection mold, standardizing die heights, centering
die, etc)
Quick Setups
Streamline all aspects of setup
– Organize workplace properly locating tools near
points of use
– Keep machines and fixtures in good repair
– Simplify or eliminate adjustments
• precoding desired settings, using locator pins, etc.
Perform setup activities in parallel or eliminate
– Add a person, standardize components, parts,
materials
Uniform Production Levels
Smoothing production requirements on the final
assembly line
– Better forecast
– Mixed production throughout the day in small
quantities
Quality at the Source
For JIT to work, quality has to be high
– No extra inventory to buffer against defective units
Producing poor-quality items and reworking
items or rejecting them is wasteful
Workers are responsible for inspection
NEVER pass along defective item
Quality at the Source
Jidoka
– Authority to stop production line if quality problems
were encountered
Andons
– Call lights activated by switches
Undercapacity scheduling
– Making time to plan, train, solve problems, maintain
work environment
Quality at the Source
Visual control
– Quality improves when problems are made visible
and workers have clear expectations of performance
– Kanbans, andons, process control charts, tool
boards, material handling routes clearly marked,
demos, instructional photos, performance data
Quality at the Source
Poka-yoke
– Foolproof device or mechanism that prevents
defects from occurring
Kaizen
– Continuous improvement
Total Productive Maintenance
Breakdown maintenance
Preventive maintenance
Total Productive Maintenance
–
–
–
–
–
–
Accurate records on time between breakdowns
Frequency of breakdowns
Costs of breakdowns
Determine a preventive maintenance schedule
Employee involvement
Zero defects
Supplier Networks
Working with suppliers to improve responsiveness and
quality
Trends:
–
–
–
–
Locate near the customer
Use small, side-loaded trucks and ship mixed loads
Consider establishing small warehouses near to the customer
Use standardized containers and make deliveries according
to a precise delivery schedule
– Become a certified supplier and accept payment at regular
intervals rather than upon delivery
Benefits of JIT
Reduced inventory
Improved quality
Lower costs
Reduced space requirements
Shorter lead time
Increased productivity
Benefits of JIT
Greater flexibility
Better relations with suppliers
Simplified scheduling and control activities
Increased capacity
Better use of human resources
More product variety