Week 5 Pull and Flow Flashcards
Flow and Pull 7 objectives
- Spaghetti charts
- Quick changeovers (SMED)
- Cellular design
- Overall equipment effectiveness
- Theory of constraints
- Pull systems and kanban signaling
- Visual workplace design
Lean 3rd principal
Create Flow
Actions that create value should occur continuously and smoothly without interruption to deliver the product or service to the customer
Inventory is evidence of non-flow
Two book suggestions
Theory of Constraints by a Gartner analyst and co-author of The Phoenix Project, George Spafford.
Third principal of LEAN
Create flow Eliminate waste create flow. Eliminate waste create flow. Eliminate waste create flow. Eliminate waste create flow.
Actions that create value should
Occur continuously and smoothly without interruption to deliver the product or service to the customer.
Topics of Flow
Spaghetti Maps
Single Minute Exchange of Die (SMED)
Cellular Design
Theory of constraints
Spaghetti maps
all steps of a persons movement
1) create map
2) observe and draw
3) analyze for improvements
SMED single minute change of dies
Sheigo shingo, Toyota, change over of dies drove lot sizes. he looked at technique to make change over faster.
SMED
Reduction in waste of waiting allows us to produce more often.
SMED 8 techniques
1) separate internal from external operations
2) convert internal to external
3) Standardize the function of holding onto parts while machining
4) use functional clamps, no screws and bolts
5) intermediate jigs; getting things into position before
6) Adopt parallel operations; pit crew at Indy
7) Eliminate adjustments (tool presetter helps)
8) Ensure mechanization, spend money on things that automate processes
SMED internal operation is
what has to happen while the machine or process is stopped
SMED external operation is
what can happen while the machine is running.
SMED implementation cycle
- Observe the process
- Separate internal from external
- Streamline internal and external activities beginning with the internal ones
- Document the new process and procedure
- Repeat the cycle
SMED, which of the 8 wastes are addressed with SMED?
All of them.
SMED, which of the 8 wastes are addressed with SMED?
All of them.
Cellular design: language water spider
water spider, someone suppling material to the cell, this is not value added.
Cellular design: language WIP
Work in process inventory, minimized in
Cellullar design: language TAKT time
customer demand of product
Cellular design: single piece flow, 4 reasons for U shape
- no corners
- materials and finished goods same entry point
- equipment grouped together
- constant motion, no waiting for machine, operator or inventory.
Cellular design: Language, 4 goals of good cellular design
- flow
- zero work in process between operations
- single piece flow not batches
- minimal transportation or motion
Work load balancing
1) observe the process (use form)
2) record time each step ends
3) do math on each step
4) look for lowest amount of time
5) look for all step time
Cycle time bar chart
After observing create bar chart for each step. Examine and change steps that do not conform to cycle time (example, 45 seconds).
Overall equipment effectiveness (OEE), 3 elements of flow:
- Availability
- Performance
- Quality
OEE availability calc
Availability = Number of Hours Running/Number of Planned Hours Running
OEE performance calc
Performance = Equipment Run Rate/Maximum demonstrated production rate (mdpr = find best day or period in last year)
OEE Quality calc
Quality (Yield) = Amount of Good Product/Total Product Produced
OEE how 3 elements affect flow
no Availability means product isn’t running.
Poor performance means a machine isn’t running efficiently and will slow down the customer
poor quality reverses flow, scrap means start over, rework means product or customers move backward in the process.
OEE two kinds of losses
There are losses that do not affect OEE and there are 6 losses that do.
OEE two losses that do not affect OEE
customer demands and planned downtime
OEE 6 major losses
1) unplanned downtime
2) downtime due to changeover
3) small downtime (cleaning, bathroom, waiting on upstream)
4) reduced performance
5) rejects due to changeover
6) quality losses
OEE six root causes
planned downtime (maintenance, changeover) breakdowns minor stops (bathroom, questions) speed law (poor lubrication, fatigue) production rejects start up waste (machine warm up)
Solve OEE with
Ishikawa diagram
Solve lots of motion with
5s
Solve lots of transport with
spaghetti map
Theory of constraints (TOC)
every process has a weakest slowest link. Book by, Eli Goldrath, “goal”.
Capacity Constraint Resource (CCR)
Do not allow CCR to be off.
- starved
- maintain just in case inventory
- mistake proof when optimizing
- don’t have unreliable CCR
Elevate the contraint by
- increasing capacity
- buy another machine
- work longer hours
- train people
- focus on the constraint (priority, center of decisions)
Theory of constraints (TOC) 5 steps
1) goal of every organization
2) CCR (capacity contrained resource)
3) elevate the constraint
4) balance the process
5) find New CCR
Fourth principal of LEAN
Create PULL
KANBAN is
a signal for the need of material. Kanbans control inventory and flow.
Online learning is
Pull
Three kinds of pull systems
1 Replenishment
2 sequential
3 mixed
Solve with Kanban 3 wastes:
over production
waiting
inventory
Who invented KANBAN?
Taiichi Ohno, the father of Lean and the Toyota production system. It means billboard sign to take action.
Replenishment KANBAN
upstream signal somethings been consumed.
Production Kanban
authorized signal from upstream
Transportation kanban
authorization to move product
4 types of Kanbans
- cards
- bins
- spaces
- electronic message
Six Kanban rules
1) consuming process picks up items.
2) producing process makes items in the quantity and sequence
3) items are only produced with kanban
4) always attach kanban to product
5) never pass on defects
6) when we reduce kanbans
Kanban steps
1) Conduct the supply survey
2) Establish reorder quantities and points
3) Create the supply order form
4) Create Kanban cards
5) Training
6) Implementation
Kanban, Reorder Quantities calc
Reorder quantity = your daily usage × your lead time in days
Kanban, Reorder point calc
Reorder point = reorder quantity + your safety stock
Supply order form, what it should include
Part image Part number Part description Prior locations Number of Kanban cards in circulation
Solve waste by continually using
Kaizen
Visual, visual visual
Picture is worth a 1000 words
Is your workplace visual?
Can someone from outside do the work at your work place? Instructions, not content can be simplified.
Same way everytime I reduce variation which eliminates defects, which eliminates the waste of also eliminates waste of waiting. This reduces the waste of non-utilized talent. And it goes on and on…
Examples of Visual
Cut outs or shadows of where tools go.
Examples of Visual - instructions
are there instructions easily available with visual images. Training
Examples of Visual - Andon
The signal for how things are performing.
Has green, yellow red light or coloring.
Examples of Visual - tool tags
Tool readiness, maintenance, red tags for tools that need service.
Examples of Visual - cellular design
Job elements abound in a good cell.
Examples of Visual - performance
Gaps in performance, production instructions and goals.
