the lean enterprise · 1. continuous process flow identified by: 2. production according to takt...
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The Lean Enterprise JIT / Cellular Concepts
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Lean Foundations
Continuous Improvement Training
2
Learning Objectives
• Learn philosophy of ‘Cellular’ production and understand 3 basic components of Just-In-Time (JIT)
• List 7 production characteristics of a JIT oriented Cell layout
• Review the steps to identify and remove waste and design a sample work cell to meet takt time
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Costs will eventually drop by relentlessly addressing these,
in succession
The Philosophy of ‘Just-in-Time’ (JIT)
Manufacture most economically:
• Only what is needed/ sold now
• Only in the amount needed now
• Only when it is needed
4
Identified by:
1. Continuous process flow
2. Production according to TAKT time
3. Pulling subsequent processes
(Refer to module on “Kanban”)
3 Components of
Just-in-Time Production
One piece/ one ‘set’ flow with no WIP between processes
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Cellular Production Characteristics
Machines in order of process
Small and inexpensive equipment
One piece flow production
Multi process handling workers
Easy moving/ standing operations
U-cell layout (Counterclockwise)
Production paced (JIT) to TAKT time
Sample
‘U-shaped’
Cell
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Production paced to TAKT time
- Output requirements determine TAKT time
- Most important measurement in manufacturing
- Operations must be constructed around TAKT time
“TAKT” Time Is The Beat Of Production
TAKT time example:
Available hrs* = 7 hrs.
Daily quantity required = 40
TAKT Time = 7 hrs X 60 min/hr = 10.5 min/pc
40 pcs
1 unit must ship every 10.5 minutes
Need to perform each operation only once every 10.5 minutes
* 8 hours minus ½ hour lunch
and two 15-minute breaks
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1. Net operating time - Normal day
- One shift @ 8 hours = 480 min
- Breaks: 2 @ 15 min = 30 min
- Available working time = 450 min
2. Customer requirements
The number of completed transactions per time period
- Orders per month = 360 - Working days per month = 20 - Average customer orders/day = 18
TAKT Time = 450 min = 25 min per order 18 Orders
Business Process TAKT Time - example
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It is composed of five elements:
1. Work sequence
2. Equipment used
3. Operation description
4. TAKT time
5. Workers required
The combination of people, materials, machines, and
methods required to produce in such a way as to
minimize waste
Standardized Operations = Best Methods
Need to know the time it takes to process the task
Sample
Cell layout
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1 2 3
4 5 6
1
3 4
1
2
Work Sequence
Raw
Material
In 2
Finished
Goods
Out
… the order in which an operator performs a series of
repetitive tasks (light blue lines below).
It should be differentiated from the processing
sequence which is the order the part or “unit” is
processed.
1
A B
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How to Remove Waste Walk the process
Process Map (refer to Mapping modules)
Collect process data
Label as value-added or non-value added
Calculate TAKT time
Graph Operational times classified as
value-added and non-value added
8 hr
Non-
value
added
Activity Bar Chart
Value
added
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How to Remove Waste
Remove or reduce non-value added steps
Challenge whether value-added steps are really
value-added (refer to Mapping Analysis modules)
Develop new layout or process
Level the load and determine the work sequence
8 hr Non -
value
added
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Proposed layout
How many people?
What would they do?
010 (Operation)
Raw
Material
In
Finished
Goods
Out
Work Center M101 020
M103
030 D201
040
D300
090
B405
080
I101
070
B205
060
B100
050
W94
A New Layout (Cell) To Reduce Waste
turning boring drilling
spot facing
cleaning de-burring
assembly inspection
packing
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TURN BORE DRILL SP'FACE CLEAN DEBURR ASSY. INSPECT PACK
0
5
10
15
20
25
30
35
40
TAKT
3 3
7
12
5 6
12
6 4
TAKT time / Cycle time
Process Time For Operations (example)
TAKT time =
(150 pc / wk) / (5 days / wk)
(2 shift/day) (7.5 hours/shift)
= 30 minutes
*Assume these are the value-added operations
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Balance the Load and Keep Waste Low
TURN BORE DRILL SP'FACE CLEAN DEBURR ASSY. INSPECT PACK
0
5
10
15
20
25
30
35
40
TAKT
3 3
7
12
5 6
12
6 4
TAKT time / Cycle time
Total Manpower = Tot. Cycle Time* 58
TAKT Time 30 = = 2
But -
keep person working in a close area to avoid waste
try to have person who “starts” the job, “finish” the job to
help facilitate working only on what is needed
have person “work with the flow” as much as possible
Combine operations for each operator
which will meet TAKT time
An iterative process with some solutions better than others
*Note: “cycle time” refers to “touch time” not “lead time” or voucher time
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D201
Proposed staffing plan
1 2
3 4 5
1 2
3 4
010
M101 020
M103
040
D300
090
B405 080
I101
070
B205
060
B100
050
W94
Raw
Material
In
Finished
Goods
Out
New Layout And Better Alignment of Work
Assignments (light blue lines)
60
50
40
30
90
80
70
Person A B
30
If TAKT time cannot be met for a given operation --
work to remove WASTE
TAKT time can be met
20 10
030
Kanban
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JIT/ Cell Concepts – Best Practices
• Balance the Work Load Among Associates
• Reduce the Walking Distances
(refer to Value Stream Mapping)
• Keep Only the Necessary Quantities of In-Process
Stock at the Work Station (refer to Kanban/ Flow)
• Automate Machine Feed and Ejection (refer to TPM)
• Change the Height, Angle or Location of the Part
Racks (refer to Kaizen)
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JIT/ Cell Concepts – Best Practices
• Change the Work Sequence (refer to Kanban/ Flow)
• Use “Two-Handed” Work Where Possible
(refer to Standardized Operations/ Standard Work)
• Reduce the Manual Adjustments Necessary to Make
Different Parts (refer to Set-up reduction)
• Use Specialized Tools (refer to Visual Management)
• Find Countermeasures to Prevent Defects
(refer to Mistake-proofing / Poka-Yoke)
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• The Just-In-Time (JIT) concept is used within Lean
Manufacturing. The idea in this philosophy is to
manufacture most economically:
- only what is needed/ sold now,
- only in the amount needed now,
- and only when it is needed
• Each operation should ‘produce’ to TAKT time.
TAKT time is determined by:
Amount of available production time
Demand
Summary
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Summary
• A value-added activity is an activity that transforms or shapes raw material or information to meet customer requirements
• A non-value-added activity (or waste) takes time, resources or space, but does not add to the value of the product or service itself
• Waste can take many forms; some of the most common are: unnecessary approvals or signatures, reviews of reviews, multiple hand-offs, transportation, correction, over-production, mass inspection
• In most cases, inventory is wasteful; more importantly, inventory hides all sorts of problems in the company
• Mapping the process and evaluating different work flow layouts is one of the keys to reducing waste
The Lean Enterprise JIT / Cellular Concepts
www.freeleansite.com
Lean Foundations
Continuous Improvement Training
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