The document compares and contrasts continuous flow and batch production methods. Continuous flow focuses on eliminating waste such as waiting time, excess inventory, and defects through one-piece flow and small batch sizes. This allows for faster cycle times, increased throughput and capacity, and reduced lead times compared to batch production which typically has longer cycle times and more non-value added time due to large batch sizes and waiting between processes. The document provides examples of value stream maps to illustrate the differences between batch and continuous flow production systems.
3. 3
Shipped on time and customer happy
We Made $$$$
ProductionMaterial
Ship order
CUSTOMER
⢠No Wasted Time
⢠No Wasted Money
⢠No Wasted Resources
⢠No Wasted Material
? ?
99%
Customer Quality
4. The truth
4
The Hidden Factory
$50000-material
scrap costs
$350,000 transportation costs
Lost order
Wrong order shipped
ProductionMaterial
Ship order CUSTOMER
Hidden Factory
5. ď˝ The systematic elimination of waste and re-alignment of resources to
deliver value to the customer faster, better, & more
consistently
ď˝ Lean also is:
⌠Pursuit of excellence
⌠Continuous Improvement of performance and quality
⌠.
⌠Increasing inventory âturnsâ and throughput
⌠Simplifying and redefining processes
⌠Measuring & monitoring processes
⌠Empowering the workforce (80%)
Leading to Leading to
Eliminate
Waste
Reduced Cycle
Times
Increased
Capacity
Focus: Eliminate waste, non-value add steps, process constraints
and bottle necks that cause problems in work
6.
7. Value Added
Typically 95% of all lead time is non-value added
1. Overproduction
2. Waiting
3. Transportation
4. Non-Value Added Processing
5. Excess Inventory/Material
6. Defects
7. Excess Motion
8. Underutilized People
Non-Value Added
5%
8. | | 8
ď§ Lack of cross-functional training
ď§ Over relying on a select few while others
are Inadequately trained
ď§ Operators are unable to rotate and help
each other out to balance the work-load
ď§ High overtime, increased pressure stress
9. ď˝ Workers can do each others work, help out
when someone is sick, on holidays, quit
ď˝ Workers help improve bottleneck operations
by helping out each other
ď˝ Variety in work making it more full-filling
ď˝ Training new workers
12. ď˝ Cycle Time is dictated by the slowest (bottleneck)
operation in the cell.
40 min
20 min
25 min
15 min
30 min
1
54
3
2
â˘What operation controls the cycle?
â˘How can you relieve the bottleneck?
13. ď˝ Bottleneck
⌠The point which is currently reducing the
flow or slowing the entire process
⌠A managed buffer before a bottleneck is
necessary
⌠A bottleneck WILL exist in every process
⌠Bottlenecks move !
⌠High WIP can mask the bottleneck
⌠The people working at the bottleneck take
breaks, not the bottleneckSource: Improve Phase 26jul07
19. FABRICATION BATCH VSM âTotal Cycle Time= 9.1 days
Customer Complaint
Total Cycle Time = 9 days
Value Added Time = 14 min
1 people
C/T = 2 min
C/O = 3 hr
Uptime = 71%
Inspection
2 people
CNC 1
C/T = 4 min
C/O = 2 hr
Uptime = 64%
2 people
C/T = 10 min
C/O = 4 hr
Uptime = 28%
WELD
2 QC
Late Delivery
5 min1 min1 min
2 days 3 day2 days 1 days
Production
Order
WK
D
Wk
6 WEEKS INVENTORY
DELIVERED EVERY
SHIPMENT TO SAVE
ON TRANSPORTATION
COSTS C/T = 12 min
C/O = 30 min
Uptime = 83%
175T PRESS
1 days
0
Customer
BSupplier
1
Supplier
2
3 weeks
lead time
WIP WIP
VA Time
NVA Time
I
30% REWORK
14% SCRAP
I
20. 3x Week
Market Forecast
Total Cycle Time = 4.1 hrs
Value Added Time = 7 min
Customer
A
Customer
B
1 people
C/T = 2 min
C/O = 20 min
Uptime = 88%
CNC 2
1 people
CNC 1
C/T = 4 min
C/O = 0.5 hr
Uptime = 78%
1 people
C/T = 3 min
C/O = 30 min
Uptime = 67%
ROBOT WELD
1 people
Shipping
Production
Control
Supplier
1
Supplier
2
C/T = 2 min
C/O = 30 min
Uptime = 93%
PRESS
D
I
3 min2 min2 min
1 hr 1 hr1 hr1 Hr
2 min
INVENTORY TURN-
OVER RATE
NVA Time
VA Time
1 Piece Flow and continuos feedback loop
1 % SCRAP
22. CURRENT STATE EATS VSM
Customer Demand
Total Non-Value Add Time = 4.5 days
Value Added Time = 173 min (2.8Hrs)
2 operator
C/T = 34 min
C/O = 0.5 hr
Uptime = 61%
Joining &
Inspection
2 operator
Tacking
C/T = 52 min
C/O = 0.5 hr
Uptime = 86%
1 operator
C/T = 47 min
C/O = 0 hr
Uptime = 78%
Manual
Weld
1 QC+ 1 welders
8 sets/day
47 min34 min52 min
1 day 2 day1 day 0.5 days
Production
Order
WK
D
Wk
INVENTORY
C/T = 40 min
C/O = 0 min
Uptime = 83%
Robot Weld
40
Customer
BLaser Break
Press
WIP WIP
VA Time
NVA Time
I
REWORK
Batch & Que Production
23. 3x Week
Market Forecast
Total Non-Value Add Time = 1.5 days
Value Added Time = 114 min ~2 Hrs
Customer
A
Customer
B
0.5 operator
C/T = 44 min
C/O = 5 min
Uptime = 70%
0.5 operator
Tacking
C/T = 30 min
C/O = 0.5 hr
Uptime = 85%
1 QC+ 1 welders
C/T = 40 min
C/O = 0 min
Uptime = 95%
Joining &
Inspection
12 sets/day
Production
Control
Laser Break
Press
Robot 7
D
40 min44 min30 min
0.5 days 1 days0 days
INVENTORY TURN-
OVER RATE
NVA Time
VA Time
1 Pc continuous flow
24. 30 min
20 min25 min
25 min
30 min
1
54
3
2
â˘What is the process cycle time?
â˘What is the process bottleneck?
New Cycle Time = 30min
25. ď˝ Get All Your Needed Material Before You Start!
ď˝ Set-up equipment as close as possible together
so you can pass parts without using boxes
ď˝ Eliminate WIP BOXES
ď˝ Set-up a white board and record hourly PPMH
compared to target.
ď˝ List any issues you have during the run
ď˝ Run 1 order at a time in the cell until itâs
completed and then next order
2