Synchronous Management or
Synchronous Manufacturing
Chapter 5 or 7
Kevin Walker
Harold Price
Chad Bachman and Jeff Denney
Evolution of Synchronous
Manufacturing
• Concept of Waste
• What is waste?
– Book Definition: Any activity in an
organization that does not contribute to the
common companywide goal of making money
– Waste elimination is a PRIME OBJECTIVE
– Everything that is above and beyond what a
company needs to be successful
Henry Ford
• Definition from Today and Tomorrow
– Having a stock of raw materials or finished
goods in excess of requirements
– Actually included all categories of inventory
stock
• Component parts, subassemblies, finished goods,
materials
Lessons From History
• THE FORD SYSTEM VS.
• JAPANESE JUST-IN-TIME
Lessons From History
• Ford’s Philosophy on Management and
Productivity
• Fully Integrated Manufacturing System
– Eliminated lost motion
– Large companies stay within a certain size or it
will be uncontrollable-a large plant is not
economical!
Ford’s System
• Maintaining a Product Flow
– Work to the worker not worker to the work
– People shouldn’t leave their worksite
– Machines do not break down because workers
are constantly cleaning and making repairs
Ford’s System
• Necessity of Good Material Control
– New System-planned a date for changeover
– Planned use exact amount of materials to that
day-changeover would not cause stop in
production
– Time Waste VS. Material Waste
• You can’t have time salvage
• Find the balance of material and time needed
Ford’s System
• Role of Quality and Inspection
– Key to production is Inspection
– It simplifies management
• Every part at every stage is inspected-eliminates
chance of faulty parts getting into assembly
Ford’s System
• Role of Labor
– System of Management NOT a system
– Is method of planning of what should be done
– All workers should follow the plans that are
laid out for them
• In summary: Ford employed Just-In-Time
Japanese Just-In-Time
• Led by Toyota
• Used Ford’s methods with some minor
improvements
• Concept of waste elimination fit well with
Japan-has limited resources
• JIT Philosophy guided the reduction of
scrap, rework, and inventory
Japanese Just-In-Time
• Major development in JIT Philosophy
– Larger role and responsibility for the worker
• Must maintain equipment
• Develop new ways to process
• Be a problem solver
What went wrong?
• Why has U.S. fallen behind in International
competition?
– No competition meant:
• Wasteful practices and unsound policies
• Meet demand at any cost
– Worldwide competition occurs:
• U.S. companies focused on cost
• Lost sight of Ford’s lessons of synchronized
production flows
Time and Product Value
• According to Ford:
– Time starts when the raw material comes from
the Earth to the moment the customer gets the
finished product
– More time used for production and sales means
less value the product has
The Product Mix
• How did Ford achieve efficiency?
• “They can have it (car) in any color they
want, as long as it’s black”
• Continuous Product Flow
– Most efficient form of production
– Identical products in batch
Philosophy of Sync. Manuf.
• Book Definition
– An all-encompassing manufacturing
management philosophy that includes a
consistent set of principles, procedures, and
techniques where every action is evaluated in
terms of the common global goal of the
organization
How Do We Implement It?
• 3 Steps
– Define the common goal so that it is
understandable and meaningful to everyone
– Develop what will cause individual actions to
relate to the common goal
– Manage the various actions to achieve the
greatest benefit
A River Analogy
• The flow of the river
– The water is never stagnant
– Water depth is the same as inventory
– Boulders and trees impede the flow of material
The Flow of the River (cont.)
• Periods of floods and droughts act as flow
problems for the river
• Lower water levels keep the stagnant pools
smaller. High levels keep the obstacles out
of the way
The Flow of the River (cont.)
• In rivers, trees visible above the water level
can easily be avoided. In a factory, visible
bottlenecks can be used efficiently.
• The problem comes when you have a tree
hiding just under the surface of the water.
• In a factory, bottlenecks can very easily be
hidden or just unrecognized.
The Traditional Approach
•
•
•
•
Keep “Just in Case” inventory
Used to not solve but to cover up problems
Gives managers a feeling of security
“Just in Case” contradicts “Just in Time”
Traditional Batch Size
• Total Setup Costs
– Large batch sizes allows less setups
• Total Carrying Costs
– Small batch sizes allows less work in progress
• Economic Order Quantity (EOQ)
– The optimum batch size to minimize Total
Costs
EOQ Batch Size
Understanding Batch Sizes
• Distinction of Resources
– Non-Bottlenecks
• Extra capacity allows for small batch sizes
– Bottlenecks
• Time is money and larger batch sizes saves time and
money
• Single Batch Size Concept
– on an assembly line, Batch sizes are BOTH
very large and one at a time
Process and Transfer Batches
• Process Batch
– The quantity of a product processed at a
resource before that resource changes over to
produce a different product
• Transfer Batch
– The quantity of units that are moved at the
same time from one resource to the next
Synchronous Manufacturing
Principles
• 1 - Do not focus on balancing capacities, focus on synchronizing the
flow
• 2 - The marginal value of time at a bottleneck resource is equal to the
throughput rate of the products processed by the bottleneck
• 3 - The marginal value of time at a non-bottleneck resource is
negligible
• 4 - The level of utilization of a non-bottleneck resource is controlled
by other constraints within the system
• 5 - Resources must be utilized, not simply activated
• 6 - The transfer batch need not, and many times should not, equal the
process batch
• 7 - A process batch may be variable both along its route and over time
Just-In-Time Systems
• Japanese success due to implementation of
just-in-time systems
• Concept of Just-in-time systems
- Finished good should be produced just in
time to be sold, subassemblies should be
completed just in time to go into
subassemblies, and purchased materials
should arrive just in time to be transformed
into fabricated parts.
Kanban Systems
• Logistical ropes connect the various work
stations and drive their JIT systems.
• Set up MPS which is determined by market
demand.
• The projected daily demand for each
product is the amount that is scheduled to
be produced for that day.
Kanban Systems, cont.
• The smoothed production schedule is then
set for a fixed period of time-normally one
month.
• Then final assembly is scheduled in order to
meet the daily production requirements.
Kanban Systems, cont.
• Toyota, which uses a dual-card kanban
system, has its own inbound and outbound
material storage areas.
*inbound stock area- holds material that is
ready for processing at the work station.
*outbound stock area- material that has
been processed and is stored until needed at
the next downstream station.
Kanban Systems, Cont.
• Conveyance kanban- a card that identifies
needed material, the feeding workstation,
and the receiving workstation.
• Production kanban- Is the signal and
authority for the work station operators to
replenish the materials just forwarded to the
from the outbound stock area.
Why Kanban systems work
• Applies the basic principles of synchronous
management.
• Principal 1: Do not focus on balancing
capacities, focus on synchronizing the flow.
• Principle 4: The level of utilization of a
non-bottleneck resource is controlled by
other constraints within the system.
• Principle 5: Resources must be utilized, not
simply activated.
Why Kanbans work, cont.
• Principle 6: A transfer batch may not, and
many times should not, be equal to the
process batch.
• Principle 7: A process batch should be
variable both along its route and over time.
Limitations of the JIT Approach
• The number of processes to which JIT
logistical systems such as kanban may be
successfully applied is limited.
• The effects of disruptions to the product
flow under a kanban system can be
disastrous to current throughput.
Limitations of the JIT Approach
• The implementation period required for
JIT/kanban systems is often lengthy and
difficult.
• The process of continuous improvement
inherent in the JIT approach is system wide
and therefore does not focus on the critical
constraints.
**Graph for Chad if he wants**
Chapter 7