LSS Week 6 + 7 Flashcards
Why must you take a structured approach to root cause analysis?
To find the true cause of the problem and implement a permanent fix
How can the Pareto diagram help you narrow the list of potential root causes?
It tells you which things occur most frequently
The null hypothesis is:
What we expect to happen due to chance alone
when would we use a paired t-test?
To test for significant changes in a sample before and after a process or time frame. Ex: Patient’s blood pressure before and after a 3-month training program.
Why is the improve phase so important to the process?
It leads you to the best solution
What is a Risk Priority Number (RPN)?
Severity, occurrence, and detection factored together
Which method of designed experiment allows for the study of all main effects and interactions?
Full Factorial
What does 5S stand for?
Sort, set in order, shine, standardize, sustain
When should you pilot your solutions?
Cost, Difficulty of reversal, and consequences.
The null hypothesis is
What we expect to happen due to chance alone
What varies more; averages or individuals?
Individuals
When should you pilot your solutions?
When failure costs are high, reversal is difficult and there may be unintended consequences.
What is the purpose of Lean?
Understanding and eliminating waste in a process
What do you need to calculate Z-scores?
The mean of the population
This method of designed experiment allows for the study of ALL main effects and interactions
Full factorial
When investigating potential root causes, what might be useful if the list becomes overwhelming?
Group them into meaningful categories but keep the full list
What are the elements of a good implementation plan?
People, budget, change management, time line, and measures for success
Why must you take a structured approach to root cause analysis?
To find the true cause of the problem and implement a permanent fix
What question does FMEA answer?
What might cause a problem?
What is the risk assessment?
What are the next steps?
What is a type I error?
When we reject the null, when in fact the null was true
During the critical root causes tollgate, what do you need to prove to the sponsor?
Eliminating the critical root causes will close gaps in performance
How can an affinity diagram help narrow a list of potential root causes?
It can identify differently named things that are actually the same or very similar
Ensuring that a fixture is non-symmetric so that a part only fits into in the correct orientation is an example of what lean tool?
Poka Yoke
How can the Pareto diagram help you narrow the list of potential root causes?
It tells you which things occur most frequently
When using a control chart, one should gather data
In the order of production
You want to find out if the average call length at a call center has decreased after implementing process improvements. What is the alternative hypothesis?
The average call time after the changes is less than the average call time before the changes
What is the key difference between prevention and mitigation?
Prevention involves error-proofing and understanding process capabilities, while mitigation aims to reduce issue severity but may not eliminate it entirely.
What tool would you use to determine whether the source of variation is due to within-piece, piece-to-piece, or time-to-time?
Multi-vari chart
Why should you conduct your trials randomly?
Minimizes changeovers, Less expensive to run & Minimizes confounding of variables with noise
The F-statistic is a ratio of what?
Variances
