Transcript Answer

Value Stream Mapping
An effective way of capturing the
current situation, identifying the
long-term lean vision, and
developing a plan to get there.
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The journey toward lean
manufacturing
For a journey, you must know:
Destination
Starting point
For the journey toward lean manufacturing
The destination (vision)
The starting point (current state mapping).
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Value Stream Mapping
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Examines and records all activities
From raw material to a finished product.
Both value added and non-value added activity
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Captures the current situation (current state)
Identifies the long-term lean vision (future state)
Develops a plan to get there.
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Find the “true north”
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Value Stream Mapping
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Learns to “see”
“The problem is not elimination of waste, but
identification of waste. Any reasonable person will
eliminate waste if he can only see it in the first
place.” --- Shigeo Shingo
Many companies don’t see
“hear no evil, speak no evil, see no evil.”

Continues improvement
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An example of current state mapping
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Current state mapping (CSM)
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A graphic depiction of what is currently happening
on the floor
Should be conducted by a cross-functional team of
people.
Data must be gathered from existing conditions on
the floor, not data stored on someone’s computer.
To gather the information, the cross functional mapping
team must walk the floor, door-to-door, following the product
as it is manufactured. CSM is a pencil-and-paper process
intended to get employees involved, as well as gain a better,
more intimate understanding of the product, process, and
information flow. Resist the urge to use a computer for this
process.
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Current state mapping (CSM)
CSM maps three flows:
Product flow
the path(s) the product takes through production, before
being shipped to the customer.
Information flow
how information is shared and communicated during the
production process.
Material flow
how incoming material is moved and replenished, and in what
quantities during production.
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Current state mapping (CSM)
The information to be gathered from the shop floor:
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Run ratios — the available time divided by the number of
good parts;
Scrap rates — the number of parts produced that are not
salvageable;
Manpower — the number of operators in the process (actual
versus required);
Work hours and schedules — the number of hours available
per day, the number of shifts per day, and the number of
shifts per week;
Changeover times — the amount of time it takes to change
from product to product, from the last good part to the first
good part;
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Current state mapping (CSM)
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Tool change times — the amount of time required
to change tooling, from the last good part to the
first good part;
Machine cycle times — the actual cycle time of
each machine, from home to home;
Inventory levels—the amount and location of all
parts, including raw materials and finished goods.
Additional measures to record
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Current state mapping (CSM)
Summary
Irrespective of metrics, sum up the process in
anecdotal terms.
How is flow?
How is pull?
How is visual?
What wastes? headaches? Inconsistencies?
What best practices (or lack thereof)?
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Icons to Be Used
Factory icon
The customer’s assembly plant is represented by a
factory icon in the upper right-hand corner.
Data box
recording the requirements of the customer.
Process/Department box.
Write key information within the data box, such as cycle
time, changeover time, and uptime.
Inventory
This is indicated with triangles to indicate “dead” flow
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Icons to Be Used
Movement
The truck icon and a broad arrow to show movement of
material from the supplier to the plant.
Production information
The process operators know what to make and in what
quantity. And what to purchase.
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Example 1
XYZ Assembly operates on two shifts and
requires daily shipments. Typically, 6,000 A units,
2,000 B units, 4,000 C units, and 8,000 D units are
needed every month. XYZ requests are palletized
returnable trays, with 20 brackets in a tray and up
to 10 trays on a pallet.
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Current State Map of Case Study Example
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Step 1: Begin with the customer’s requirements
To be drawn in the
upper right-hand
corner.
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Step 2: Draw the basic production processes
and count the inventories
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Step 3: Add Supplier(s)
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Step 4: Add Information Flow
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Step 5: Add Lead Time
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Analyze the Current State
Many symptoms of mass production
All processes in the value stream receive a schedule from
production control ---------- “push system”
Independent Efficiency
The traditional mass approach is to attain maximum utilization
of equipment, manpower, and materials in the following order
of descending priority:
equipment, manpower, and materials.
For Toyota, if anything, the order should be reversed. Toyota
coordinates the three to increase efficiency-----Toyota’s “total
efficiency”
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Analyze the Current State
Waste of Overproduction
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Work-in-process accumulates after each machine and
each process.
Material handling between processes is two or more
times what it should be.
There is poor response to changes in specifications or in
products.
There are extremely long production lead times.
The workflow and production sequences cannot be
standardized.
Waste of Correction (Rework Parts)
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Analyze the Current State
Inflexibility
The current state data in Figure 4-1 shows the machining
changeover takes one hour, and the assembly process takes
10 minutes. This indicates that there is little flexibility in
product changeover.
Changeover time is an important issue with processes that
produce a number of different parts.
Lower Process Uptime
CSM identifies significant amounts of unplanned downtime in
the machining lines. Causes for downtime need to be
identified
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Analyze the Current State
Intrinsic Fallout
• Shop floor “specialists” spend time throughout each day
counting work-in-process and raw materials to make sure
they can meet their schedule. This is a people-dependent
activity, not a process-dependent activity.
• Shop floor operators and supervisors are not empowered
to make daily decisions because the “schedule from
above” will decide that for them.
• There is a difficult level of housekeeping to sustain. The
amount of waste to support the push system ties up
resources that could otherwise be available to sustain the
effort.
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Utilization
hoursactually worked
Utilization 
100%
Availablehours
Example 2:
A work center is available 120 hours but actually
produced goods for 100 hours. What is the utilization of
the work center?
Answer
Utilization = 100 / 120 (100%) = 83.3%
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Efficiency
Actually rateof production
Efficiency
 100%
Standard rateof production
Example 3:
A work center produces 120 units in a shift. The
standard for that item is 100 units a shift. What is the
efficiency of the work center?
Answer
Efficiency = 120 / 100 (100%) = 120%
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Rated capacity
Rated capacity is calculated by taking into account the
work center utilization and efficiency:
Rated capacity = available time X utilization X efficiency
Example 4:
A work center consists of four machines and is operated
eight hours per day for five days a week. Historically, the utilization
has been 85% and the efficiency 110%. What is the rated capacity?
Answer
Available time = 4 X 8 X 5 = 160 hours per week
Rated capacity = 160 x 0.85 X 1.10 = 149.6 standard hours.
We expect to get 149.6 standard hours of work from that
work center in an average week.
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Capacity required
Hours of work required at each work center in each time
period.
Example 5:
A work center is to process 150 units of gear shaft SG 123 on
work order 333. The setup time is 1.5 hours, and the run time is 0.2
hours per piece. What is the standard time needed to run the order?
Answer
Total standard time = setup time + run time
= 1.5 + (150 x 0.2)
= 31.5 standard hours
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Capacity required
Example 6:
In the previous problem, how much actual time will be
needed to run the order if the work center has an efficiency of 120%
and a utilization of 80%?
Answer
Capacity required = (actual time)(efficiency)(utilization)
capacityrequired
Actual time
(efficiency)(Utilization)
31.5

=32.8 hours
(1.2)(0.8)
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Creating The Future State Map
Simple goal of lean manufacturing:
Produce the highest quality at the lowest total cost in the
shortest lead-time, with flexibility to respond to changes.
Lead-time consists of non value-added time and
value-added time.
The challenge in developing the future state is to
produce the customer’s requirements (within
specification) in the shortest lead-time and at the
lowest cost.
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Creating The Future State Map
In the example 1 current state map (Figure 4-1), how
to reduce the lead-time?
The answer is to prevent overproduction.
Three tools are used to prevent overproduction and
reduce leadtime
---Takt time
---Kanban
---Load leveling
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Where Can One-piece Flow Processing Be
Applied?
1. The largest cycle time in the line should be less
than takt time.
2. The line should be balanced (The cycle times
should be even).
3. Flexibility
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Is it necessary to replenish the pull?
1. If the manufacturer knows customer is withdrawing
from the finished good’s marketplace, then a
process needs to be established to replenish only
what the customer is withdrawing.
2. Takt time was established.
3. The downstream process (assembly) is required to
replenish the full range of products on a daily
basis, so there must be a one-day marketplace for
all products.
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Should Production Be Scheduled?
• There is sufficient lead time from when the build
signal is received to produce and deliver to the
customer’s fitment point.
• It is practical and possible to flow the product
from this point forward.
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Future State Map
At which stations, are parts withdrawn?
At which stations, are parts scheduled?
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What Should be the Withdrawal
Frequency of Finished Goods?
In the example 1 of Figure 4-17, the daily requirements of
products A, B, C, and D would look like this:
A = 300/day
C = 200/day
Container quantity = 20
B = 100/day
D = 400/day
Therefore, the number of containers per day is:
A = 15
B=5
C = 10
D = 20
The withdraw interval = 840 minutes / 50 containers
= 17 minutes
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Future State Map
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Future State Map
The FSM of Figure 4-18 shows:
The addition of load-leveling board.
The impact of the amount of FGs necessary to support the
customer’s requirements if the withdrawal frequency was
increased to four times per day.
A further 0.8 of a day of lead-time can be cut from the stream.
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Compare Current and Future
• Where is the bottleneck?
• What is the big system problem?
• How can “push” be changed to “pull”?
• Where are the key process kaizen opportunities?
• What are the logistical, behavioral and policy barriers to
reaching ideal?
• What target is realistic for this improvement?
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Create An Action Plan
1.
Background
2.
Current Condition
3.
Problems/Effects
4.
Target Condition
5.
Countermeasures/ Results
6.
Key Measures
7.
Timetable
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Timetable
Draw a Gantt chart with major milestones for implementation of
countermeasures.
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Carry Out The Plan
1 . Plan for air, electric, water, computer
2. Plan for safety
3. Start as soon as possible. Don’t wait for perfection.
4. Do it as a team.
5. Don’t spend money. Prove out the plan first.
6. Don’t be afraid to act.
7. Be prepared to make on the spot adjustments.
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Video Example
Lathe Cutter Making
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