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.
What are the steps in 5S?
- Seiri (sort) - identify used and unused items
- Seiton (set-in-order) - identify designated areas for storing items based on their usage frequency
- Seiso (shine) - clean the workspace
- Seiketsu (standardize) - establish guidelines, procedures and visual cues to ensure the first three S are maintained & communicated
- Shitsuke (sustain) - establish procedures to ensure the improvements are sustained (e.g., auditing, training, engagement programs)
Differentiate between gemba, gembutsu and genjitsu.
Gemba means going to the location where value happens.
Gembutsu means reviewing the actual product at hand from the perspective of customer.
Genjitsu means viewing the actual facts and data and acting upon it.
What does the first part of FMEA involve?
- Process/machine in question
- Failure mode - how the process can fail
- Failure effects - what are the implications of failure.
- Severity - a rating on the severity of the consequences
- Causes - potential causes of the failure mode
- Occurrence - the frequency in which the failure happens
- Controls - The current control in place to manage the failure mode
- Detection - a rating on how detectable is the issue before it gets to the customer
- RPN - risk priority number - product of SDO
What are the general steps in conducting a SMED project?
- Identify a pilot area
- Identify changeover elements
- Separate external changeover elements
- Convert internal elements to external
- Streamline the remaining elements
What is SMED?
Single minute exchange of die. It is an endeavour to reduce changeover time by converting internal changeover elements to external.
An ideal candidate for SMED project will have what kind of characteristics?
- Long changeover duration
- Large variation in change over time
- Multiple opportunities to conduct the changeover in each week
- Familiarity with the equipment
- The equipment is the constraint of the changeover process
In SMED, what can be done to streamline the changeover elements?
- release - eliminate nuts and bots through quick release machanisms
- eliminate adjustments
- eliminate motion by organizing workspace
- eliminate waiting time before line startup
- standardize hardware so same tools can be used
- create parallel operations
- mechanize - automate certain processes using machinery
What are the key steps in constructing a VSM?
- Identify product family/scope
- Construct the information flow starting from the customer
- Construct process/material flow
- Calculate VSM metrics (i.e., C/T, L/T, C/O, Uptime, Availability, %C/A)
- Construct the time ladder.
- Calculate the PCE% (VA/LT *100)
- Construct the future state map.
What are the 4 ways to deal with risks?
- Avoid the risk
- Mitigate/Reduce the risk
- Transfer the risk
- Accept the risk
Differentiate between checklists and check sheet.
Checklists - A to-do list aimed at preventing key tasks from being missed out
Check sheet - A form used to capture quantitative & qualitative observations
What does RACI stand for?
Responsible, Accountable, Consulted, Informed
Describe the way of managing different stakeholders based on the power-interest grid.
High power low interest - Keep satisfied
Low power low interest - monitor
High power high interest - manage closely
Low power high interest - keep informed
What are the 3 factors that the salience model considers?
Power, Urgency, Legitamacy
What is the objective of hoshin kanri?
To translate long-term objectives to annual objectives, priorities activities and KPIs.
What are the advantages of doing a QFD?
- To understand customer needs
- To prioritize resources
- To document customer requirements
- To develop goals based on customer needs
How do you perform a QFD using the HOQ approach?
- Identify VoC at the left side & weigh them according to importance (%)
- Identify technical requirements at the top side.
- Establish the strength of the relationship between technical requirements & VoC in the matrix
- Calculate the importance rating by multiplying the strength of relationship rating and the importance weightage.
- Complete the correlation matrix between factors at the roof.
- Add competitor as a benchmark at the right side.
What are the 8 pillars of TPM?
- Autonomous maintenance (AM)
- Planned maintenance (PM)
- Quality integration (QI)
- Focused improvement (FI)
- Early equipment management (EEM)
- Training and Education (T&E)
- Safety, Health and Environment (SHE)
- Office TPM
Describe the metrics in OEE .
Performance: (Ideal Cycle Time X Total Count) / Actual Run TIme
Availability: Actual Run Time/Planned Run Time
Quality = number of good units/number of unit produced
What are the two formulas for OEE?
OEE = Availability x Performance x Quality
OEE = (Good count x Ideal Cycle Time)/Planned Production Time
What are the OEE benchmarks available?
100% - Perfect Production
85% - World Class Performance
60% - Typical production performance
40% - Low performance
What are the 6 big losses as described in OEE?
- Unplanned stops
- Setups and adjustments
- Small stops
- Slow run
- Defects
- Reduced yield
What is TPM?
TPM is a holistic approach of equipment management to attain perfect production & support JIT.
