Lean Methodology Flashcards
What are the 7 major waste?
Transportation
Inventory
Motion
Waiting
Over-processing
Over-production
Defects
(SKILLS)
What is takt time?
Available production time/customer demand.
It gauges how fast the process need to be in order to meet customer demand
What is cycle time?
Net production time/number of unit produced.
It gauges how fast the process currently is in time required/unit product
What does Muda, Mura and Muri mean?
Muda - wasteful/useless activity
Mura - unevenness/irregularity
Muri - overburden
What is the lead time?
The total time from order initiation to product completion and delivery.
What are the 5 Principles of Lean?
- Identify Value and Waste
- Map the Value Stream
- Establish Continuous Flow
- Establish Pull
- Continuous Improvement
What are the two major pillars of Lean?
Just-in-time - producing what is needed, when it is needed, in the quantity that is needed.
Jidoka - Autonomation (automation with a human touch) through harmonizing machineries and operator autonomy.
What forms the basis of the house of Lean?
Standardization & 5S.
How should we manage VA, VE and NVA activities?
Seek to:
Optimize VA
Minimize VE
Eliminate NVA
Differentiate between Muda, Mura and Muri
Muda - refers to useless activities or waste
Mura - refers to un-evenness or variation
Muri - refers to overburden
If a production plant has a takt time of 1.5 hours per unit, while the cycle time is 1 hour per unit. Can this plant meet the customer demand?
Yes, cycle time is lower than takt time, which means the plant is producing faster than the demand rate of customers.
What are the 5 categories of customer needs according to Kano model?
- Basic needs - if absent cause dissatisfaction, but presence does not increase satisfaction
- Performance needs - features that are directly correlated with satisfaction.
- Excitement needs - features that increase satisfaction, but does not cause dissatisfaction when absent
- Indifferent needs - features that is not associated with customer satisfaction
- Reverse needs - feature that when present, cause dissatisfaction
What does a triangle in a VSM signify?
A triangle signifies inventory
In a VSM, what is the difference between a straight arrow and a zig-zag arrow?
Straight arrow indicates manual information flow, while a zig-zag arrow indicates digital information flow.
What does the top part and the bottom part of the lead time ladder in a VSM indicate?
Top - Waiting time
Bottom - Processing time
What does a spaghetti diagram do?
A spaghetti diagram visualizes the physical movement of people in a process to help identify waste in motion/transportation. It is useful in layout planning.
What is Heijunka?
Heijunka means levelling a process. Heijunka aims to even out the workload across all sub-processes to reduce overburden (Muri) and time spent waiting for another process to complete.
Describe the two types of Heijunka.
Heijunka by volume: Involves finding out the average demand per time period (e.g., week) and maintaining steady production volume while keeping some buffer stock. This is to prevent sudden fluctuations in production volume.
Heijunka by type: Involves finding out the average demand per time period for each type of item produced at the line, and spread the changeover out evenly throughout the week. One can use the Heijunka box for this activity.
What are the key principles of Jidoka?
- Discovering process abnormalities
- Stop your work to prevent quality issues
- Fix problems in a timely fashion
- Identify and eliminate root causes.
How does andon align with Jidoka?
Andon is a visual signalling system designed to inform people about abnormalities. With andon, machines and processes are self monitoring, which frees up operators’ time to do VA activities.
What is standardized work?
Standardized work is a process where work sequences are structured and documented. Operators conducting the work have the autonomy and responsibility to constantly revise the standardized work to improve upon it.
What is a pull-flow?
A pull flow is the process of triggering replenishment based on consumption.
This is different from the traditional push flow where processes are “make-to-sell”. Pull flow is akin to “make-to-order”,
What are some benefits of layout planning?
- Improved flow of materials and information
- Reduced waste in motion and transportation
- Improved safety
What are the types of layouts available?
- Process layout: arranging workstations according to their functions
- Product layout: arranging workstations in sequence based on the processes the products need to go through
- Fixed position layout: placing the largest and most cumbersome process in the central area and keeping other tools & workstations mobile
- Hybrid layout: a mix of process, product and/or fixed position layout
- Cellular layout: grouping equipment and machines together in cells to produce similar items.