Week 4 Mapping the Value Stream Flashcards
Second principal of Lean
Map the Value Stream, a key tool.
Once you know what value is, the next step is…
to find out where it comes from and, consequently, where it does not occur.
In mapping the value stream, we will…
map all the activities that contribute to delivering the product or service from end to end, from supplier to customer�
Value stream map is… (2nd lean step)
a single tool that identifies value, shows you the waste, communicates the process, and focuses your efforts.
When implementing Lean, especially at the organization or enterprise level or the process level, it is strongly encouraged to… (2nd lean step)
do the value stream map step immediately after identifying value
One good value stream map can…
generate the information necessary to drive many kaizen events, large and small
What is a process?
a repetitive and systematic series of steps or activities where inputs are modified, or transformed, into what we hope will be value-added outputs that the customer is willing to pay for.
(the steps connecting input and output)
Three perceptions of a process (which is focus)
- What you think it is.
- What it actually is (one to focus on)
- What it should be
Why do we need a process focus?
Understand how and why things get done:
• link our customer and supplier relationships
• do more with fewer resources without compromising quality.
• see the process as it is, understand what is contributing to the issues we are seeing (main focus)
• Stop blaming from people to process
- Tip: if you give your people better processes, then you will get better performance from them.
Give a process a name.
Voice of customer vs. process
• Voice of the customer
- Set specifications, targets, and requirements
- The customer tells you what they will tolerate, and what they will not
• Voice of the process
- Cycle time
- Defects
- Waste
Lean focus is on both…
Lean is focused on process but needs to be connected to the customer.
6M’s to facilitate brainstorming are…
Identify sources of variation, ask about all of them: “ what is it about man in the process”
- Man
- Machine
- Material
- Method
- Measurement
- Mother nature
4 Main flow chart symbols
Current and future state
• Oval – starting or ending point in the flow chart
• Step – a rectangular box, usually a process step
• Decision diamond – usually a yes/no scenario (exception handling, right)
• Connector – a circled letter, or possibly a number, indicating its match on another page
Flow chart drawn in columns is a ? (give MPD example)
Swim lane flow chart Examples of MPD columns: 1) artist/creative 2) agency 3) printer 4) MPD 5) end customer
Flow chart in columns is a ? (give agency example)
Swim lane flow chart Examples of agency columns: 1) customer 2) agent 3) insurance rep 4) underwriter 5) customer service
Value stream mapping 3 rules
1) simple basic; 10-15 steps
2) each member creates their own mapes
3) train how the map is to be created
Value stream mapping process
1) Educate the team on how to create a map
2) Initial Brainstorm
3) scope the project
4) complete a waste walk
5) rough-cut map, final and current state
Value stream mapping symbols
- Supplier, customer
- Transportation/shipping
- Kaizen burst (rapid improvement)
- Operator symbol
- Supermarket (inventory pull) symbol
- Process box with data symbol
- Electronic flow symbol
- Push arrow symbol (downstream full-up)
- Manual Information (paper flow)
- Inventory symbol (2nd, tombstone waiting to die)
- Go see symbol
- Timeline
Timeline symbol described a bit more
The timeline symbol is where you capture the value vs non-value-add times
- Capturing these times gives you a summary of what is going on in your value stream and what the customer would be willing to pay for/not be willing to pay for
What data is relevant for the data box?
- Cycle time
- Changeover time
- Uptime
- Reasons for delays
- Batch size
- Number of resources used in the process boxes
Value stream, Key measurements (data), 4 typical improvements…
- Shortening lead times
- Reducing costs
- Improving quality
- Increasing output
Value stream, key measures (data) elements include these 3 items:
• Cycle time – the amount of time it takes for a product, service, or customer to move through this process step
• Changeover time – the downtime associated with changing products for a machine that makes multiple items
- Similarly, in loan processing the time it takes to go from a first-time home owner’s loan vs. a typical mortgage may require downtime
• Non-value-added time – the time within this cycle time that the customer does not pay for - May require a time study
Value stream, key measures (data) elements other information:
- Yield as a percent
- Scrap
- Value-added time
- Number of shifts
- Number of employees
- processor speed
- cost per unit
Five LEAN principles
1) Define value
2) Map value stream
3) create flow
4) Establish Pull
5) Pursue Perfection
Difference between process and value stream maps.
The addition of key data that helps solve the problem helps show if the step needs improvement.
A value stream map shows the non-value activities (current state).
Data box elements
Value stream map, systems or data
- cycle time
- change over time (downtime)
- non-value added time (time customer doesn’t pay for)
- other elements:
- yield (quality improvement)
- scrap (associated with a step)
- overall equipment effectiveness (OEE)
- value added time
- number of shifts
- number of employees
- processor speed
- cost per unit for processor step
TAKT time definition
A data element
German word for conductor baton, meter.
Customer demand rate, amount of time to deliver each product or service to keep up with demand.
TAKT time, net available
Available time:
3 shifts x 8 hours x 60 minutes x 60 seconds=86,400s
less: breaks, 3 x 40 x 60 = 7,200s
Net available time each day: 79,200s
customer wants 200 parts per day
Takt is seconds / part or 79200/200=396s/unit, can be converted to minutes, 396/60=6.6 min/unit, or 6:36 per min/unit.
TAKT time MPD example
1x8x60x60=28,800
less 1x 45 (15brk + 30 lunch) x 60= 2,700s
net available time each day: 26,100
MPD customer demand: 1,100,000 / 2080 x 8 hrs = 4,230 /day
Takt is seconds / part or 26100 / 4230 = 6.17s/unit, can be converted to minutes, nsg.
Other data measures: Yield formula
(Parts/services delivered) / (Parts/services produced/attempted to deliver)
Yields complement is “scrap” (parts not delivered/services)
MPD? job incoming pieces finished 9,500 / pieces received 10,000=95% RTY?
Other data measures: Rolled Throughput Yield (RTY) formula
Yield at each step x each step.
step 1 yield x step 2 yield x step 3 yield = 0.75x0.95x0.85=0.605 or 61% RTY.
Other data measures: Available time formula
Amount of time the process should be running.
Other data measures: Up time
Percent of available time
amount of time the process is actually running / available time
Other data measures: Down time
Complement to Uptime
Other data measures: Machine capacity
Number of units the machine can produce during the available time/number of services can deliver.
Other data measures: Available or open capacity formula
Percent of available time that is not running due to lack of customer demand.
MPD = they keep this to a minimum.
Other data measures: Machine availability formula
(percent of minutes running) / (minutes available)
differs from uptime, Do Not remove change over time in this calculation.
Other data measures: Change over time formula
Time between producing parts.
from stop to start again
Takt and other data comparison
Takt time (cust. demand) 52800 / 1000 = 52.8s/unit,
- plan cycle time should always be less than Takt time.
- covers unplanned downtime waste
Value stream map, why?
Allows us to see flow of information (sipoc) AND material (spaghetti), see relationship between value added time and lead time.
Value stream map book origin?
book: “Learning to See”, Mike Rather
- try not to fix everything at once.
- optimize door to door
Steps to build a Value Stream Map
1) draft end to end process steps
2) go to gemba - see the steps
3) confirm transactional steps and inventory
4) farm existing data for data box items
5) go to gemba to confirm data box information
6) count inventory at each step
Why current and future state maps?
Celebrate successes
Future, allows to dream, plan kaizen events
(if you know how to get there, you haven’t stretched)
Focus on value and eliminate waste
Value stream map
