Prelim 1 – Module 3 Flashcards
Dimensions of Service Quality (5)
- Reliability: Perform promised service dependably and accurately (no defects!)
- Responsiveness: Willingness to help customers promptly
- Assurance: Ability to convey trust and confidence, e.g., being polite and showing respect for customer
- Empathy: Ability to be approachable, e.g., being a good listener
- Tangibles: Physical facilities and facilitating goods, e.g., cleanliness
What factors into expected service vs. perceived service?
- Word of mouth
- Personal needs
- Past experience
Service Quality Assessment
- Expectations exceed ES<PS (quality surprise)
- Expectations met ES ~ PS (satisfactory quality)
- Expectations not met ES>PS (unacceptable quality)
Service quality gap model
Gap 1: market research
Gap 2: design
Gap 3: conformance
Gap 4: communication
Gap 5: customer satisfaction
Lean service philosophy
- Satisfy the needs of the customer by performing only those activities that ADD VALUE in the eyes of the customer.
- Define the “VALUE STREAM” by flowcharting the process to identify both value-added and non-value-added activities. Scope out opportunities for improvement into Kaizen bursts, or small projects to make small incremental changes.
- Eliminate the waste. Waste in the value stream is any activity for which the customer is not willing to pay.
Lean ideas and illustrations
- continuous flow
- gemba walks (“real place”)
- 5S to organize work area
- automation
- kanban (pull not push)
- kaizen (continuous improvement)
- poka-yoke (“error proof”)
- value stream mapping
- standardization
- looking for mudas in services
- visual factory
- plan-do-check-act
Dig Inn
- never put the bowl down: continuous flow; kanban
- a manager going through employee training: gemba walk
- designing scoops to automatically portion: poka-yoke; standardization
- test squad: plan-do-check-act; kaizen
Lean’s 7 wastes
- transport
- inventory
- movement/motion
- waiting
- overproduction
- overprocessing
- defects
Transport waste
Moving inventory, people, or tools farther than necessary
Inventory waste
Storing products not needed at this time
Movement/motion waste
Unnecessary movement of people or items within a work centre
Waiting waste
When customers, patients, or parties sit idle
Overproduction waste
Producing more of a product than can be consumed at that time
Overprocessing waste
Doing more work than the customer values
Defects waste
Doing something of poor quality and then later fixing or scrapping
Example of waste: agents walk down jet bridge to confirm aircraft ready to board
Waiting, transportation
Example of waste: agents put “approved” takes on carry-ons
Overprocessing
Example of waste: using the same aircraft-turnover process for on-time and delayed flights
Overprocessing, waiting
Example of waste: flight attendants count passengers
Waiting, overprocessing
Key detail of value stream map and efficiency formula
Value-added time and non-value added time
Efficiency = value added time/throughput time
What is six sigma (6σ)?
- define
- measure
- analyze
- improve
- control
Normal distribution: below x, above x, out of specifications
Below: norm.dist
Above: 1-norm.dist
Out of specification: the above added together
Why is six sigma associated with 3.4 defects per million opportunities?
Consider a process with a mean μ, standard deviation σ, and lower/upper specification limits.
In stable processes, the mean naturally shifts by up to 1.5σ (let’s say μ=1.5σ)
When mean is centred between specification limits
𝐶𝑝=(𝑈𝑆𝐿−𝐿𝑆𝐿)/6𝜎 𝐶𝑝=(+15−(−15))/(6(2.5))=2.0
𝐶𝑝 ≥ 2.0 is acceptable level of process capability for Six Sigma standards
When mean μ is not centred between specification limits
𝐶𝑝𝑘=𝑚𝑖𝑛[(𝑈𝑆𝐿−𝜇)/3𝜎,(𝜇−𝐿𝑆𝐿)/3𝜎] 𝐶𝑝𝑘=𝑚𝑖𝑛[(15−1)/(3(2.5)),(1−(−15))/(3(2.5))]=𝑚𝑖𝑛[1.87,2.13]=1.87
𝐶𝑝𝑘≥2.0 will be more difficult to achieve
Six sigma tools: defining goals
SMART: specific, measurable, action-oriented, reasonable, timely
Six sigma tools: determining the cause of the problem
Flow charts, pareto diagrams, fishbone diagrams, the five whys, check sheets
Six sigma tools: controlling the quality
Run charts, quality control charts, kanban, 5S, pokayoke
5S technique
- sort
- set in order
- shine
- standardize
- sustain
Sort
Eliminate obstacles and unnecessary items
Set In Order
Arrange items for convenience, clarity, and smooth workflow
Shine
Keep clean and safe; make problems easy to detect
Standardize
Standardize best practices; make easy to find things
Sustain
Ensure clarity of standards; audit; promote training and discipline
Poka-yoke: can you ensure perfect quality?
Mistake proofing, inadvertent error prevention, idiot-proofing
How can you poka-yoke a spreadsheet?
- drop-down boxes
- locking cells
- hiding worksheets
- setting the print area
- conditional formatting
Control Charts (we study three types: 𝑋̅-chart, R-chart, p-chart)
- Plot average values of a performance measure over time to determine if a process is in control
- Conceptually similar to confidence intervals
- Established using representative historical data
Take action if
- sample mean outside control limits
- run of seven means above/below mean
How do you determine the control limits? (R-charts)
R-charts depict the range (highest minus lowest observation)
Often used prior to 𝑋̅-chart in order to first see that variability is in control
Need to know sample size (n)
-> if range values are between UCL and LCL, our process is in control
If observation is above UCL or lower than LCL
Take action
What if the error measured is a frequency/percentage?
Use a p-chart
𝒑̅=𝑒𝑠𝑡𝑖𝑚𝑎𝑡𝑒 𝑜𝑓 𝑝𝑜𝑝𝑢𝑙𝑎𝑡𝑖𝑜𝑛 𝑝𝑒𝑟𝑐𝑒𝑛𝑡𝑎𝑔𝑒 (𝑤𝑒𝑖𝑔ℎ𝑡𝑒𝑑 𝑎𝑣𝑒𝑟𝑎𝑔𝑒)
