BME 481 Midterm Review

DMADV

Define, Measure, Analyze, Design, Verify

DMAIC

Define, Measure, Analyze, Improve, Control

DMADV vs DMAIC application

DMADV is for a new design/process, DMAIC is for optimizing an existing process

Explain where six sigma term came from

process performance must remain within 6 standard deviations of the specification (only 3.4 defects/million).

Motorola Shift

motorola allowed a process to shift 1.5 sigma before bringing it back to center. it's not practical to always be "perfect"

problem statement must include....

amount of defects, period of time, cost of the "pain"

mission statement must include...

expected improvement, targeted completion date, expected cost savings

voice of customer examples

method used to take customer expectations, preferences, and feedback and translate it into measurable requirements

VOC --> CTQ example about pizza

"i want my pizza delivered hot" --> "90% of our pizza delivered within 15 min of leaving the store"

resources to find VOC

complaints, returns, surveys, interviews, warranty requests, mailed questionaire, interviews, focus groups

steps of an affinity diagram

VOC --> CTQ --> Project Metrics (Y)

MSA definition

measurement systems analysis. scientific and mathematical method used to evaluate the quality, reliability, and capability of a measurement system.

why is it important to do MSA

the ability to measure process and material parameters accurately and precisely are critical for making decisions that affect project. The system must be analyzed and improved before data is collected or else how do u know if anything has changed

measurement system definition

complete process used to collect data. the people, methods, equipment, technology employed in data collection.

two types of MSA

Variable (Continuous) and Attribute (Discrete)

variable MSA definition

Evaluates continuous numerical data (length, weight, temperature, time). It assesses how much variation comes from the gauge itself versus the operators using it.

attribute MSA definition

Evaluates categorical or pass/fail (go/no-go) data (visual defects, accept/reject decisions). It uses metrics like individual, group, and department effectiveness.

repeatability vs reproducibility

repeatability focuses on error from the gage, reproducibility on the operator

process stability

measure of how accurate the system performs over time

process bias

deviation of measured value from actual value

process linearity

measure of how size affects accuracy of measurement sytem

SIPOC abbreviation

suppliers, inputs, process, outputs, customers

value stream mapping

material and information flow map

information inside the data box of value stream map

cycle time, changeover time, up time (machine reliability), yield rate

daily demand rate calculation

monthly demand /days

3 categories of customer satisfaction

must haves (basics, essentials), more is better, delighters

hotel feature example of 3 categories of customer satisfaction

must have: Bed

more is better: TV size

delighter: chocolates on the pillow

draw the kano model

roll throughout yield definition

amount of product that goes through process without problems. multiplying the yield rate at each step

purpose of run charts

"is process changing over time?"

purpose of pareto chart

"20% of the defect types cause 80% of the problems"

purpose of histogram

shows us spread, location, and distribution

purpose of fishbone/ishikawa/cause&effect diagram

identifies different categories of error that could be contributing to the process issues

6 categories of ishikawa diagram causes

measurement, material, manpower, mother nature (environment), method, machines

purpose of box plots

lets you compare different processes and compare performance

purpose of scatterplot

observe relationship between 2 variables

FMEA definition

failure mode error analysis. step by step approach to identify the potential failures in a design, process, product, or service. a way to identify, estimate, prioritize, and evaluation risk

dFMEA vs pFMEA

DFMEA focuses on preventing product design flaws before production begins, while PFMEA focuses on preventing manufacturing and assembly errors while the product is being built.

how to calculate RPN

severity x occurrence x detectability

severity definition (FMEA)

how severe is the effect on the customer?

occurrence definition (FMEA)

how often does the cause of failure occur

detectability definition (FMEA)

how well can you detect the cause of failure mode?

two sample t-test definition

test for 2 population means to determine whether there is a significant difference between the 2 populations. 2 populations must be independent of each other

explain Y = f(X)

what are you investigating or changing (X's) to affect the final outcome (Y)?

5 S's of Lean Manufacturing and their definitions

- sort = keep only what is needed

- set in order = a place for everything and everything in its place

- shine = clean up area, look for ways to prevent dirt/contamination

- standardize = create procedures and rules to maintain sort/set/shine

- sustain = making sure the procedures are kept up with

standardized work definition

the least waste way, designed by worker, not engineer. provides a stable, repeatable process. aids in training employees

takt time vs cycle time definition

takt = time allowed to produce one unit (IDEAL), cycle = time it takes operator to produce one unit (ACTUAL)

8 wastes of lean manufacturing

DOWNTIME!

Defects, Overproduction, Waiting, Non-value added processing steps, Transportation, Inventory (excess), Motion, Employee knowledge

value definition (lean thinking)

what customers are willing to pay

value stream definition (lean thinking)

steps that deliver the value

flow definition (lean thinking)

organizing the value stream to be continuous

pull definition (lean thinking)

responding to downstream customer demand

perfection definition (lean thinking)

relentless continuous improvement (culture)

different people roles in six sigma project (from top to bottom)

executive, champion, MBB/black belts, green belts

% contribution in a Gage R&R study

how much of the total process variation is caused by the measurement system itself versus the actual part-to-part variation. u want it to be as low as possible

DMAIC - tools for define

SIPOC, stakeholder analysis, VOC, CTQ

DMAIC - tools for measure

Detailed Process Map, Data Collection Plan, Gage R&R, FMEA

DMAIC - tools for analyze

Graphical Analysis, Variation, Hypothesis Testing, Fishbone, 5 Whys, Spaghetti Diagram

DMAIC - tools for improve

Regression Analysis, Poka-Yoke, Kaizen

DMAIC - tools for control

Control Plan, Control Charts, Sigma Calculation, Financial Signoff, Change Management

poka yoke definition

any mechanism or design feature in a process that prevents, corrects, or draws attention to human errors as they occur

kaizen definition

continuous improvement

DMADV - tools for design (second D)

Prototyping, DOE, poka yoke

DMADV - tools for verification

hypothesis testing, pilot testing, control charts/plans