six sigma3

7/30/2019 six sigma3

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Preparation 1 Decide X which is measured.

Investigate all of source X Process Map

Narrowing X with technology discussion or Cause & Effect diagram

or Quality matrix

Predict potential failure before MP FMEA

Preparation 2 Investigation of the reliability of the data which is measured.

Pass / Fail data Attribute Gage R&R

Quantitative data Variable Gage R&R

Define Measure Analyze Improve Control

Measure data which shows the relation of Y and source X.Yfx

Narrowing X with discussion


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Process Map

Objective Investigate X (failure sources) effecting to process

as many as possible.

Operators have information. Please ask them.There are many examples which give big hint of solution.

Observe operation carefully. And acquire your knowledge

more than other persons.


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It is the diagram which shows divided process and processing machine into some working

step. And it shows the relation offactor (X) and output (y and Y). It equivalent to Cause

and effect diagram (Fish bone diagram) which is one of the QC 7 tools.

What is Process Map?

Working step A

Factor XX

etc

Output

Working step N Final Output Y

Factor (X) Material, setting value, operator, environment, etc.

Output (y) The result of each working step or the status of products at each working step

Output (Y) Products status (size, location, weight, strength, vibration, voltage, S/N,

scratch, etc.)

Factor XX

etc

Output

X has variation y has variation Y has variation Product sometime

become failure.)


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If champions indication scope (activity scope) is too wide, the improvement efficiency is bad.

Narrowing project scope to be better efficiency. (it is sometime impossible.)

Total process improvement Equipment improvement ( one or some)

Before making Process Map

Equipment

Failure rate 0.1%Sub

AssemblyProducts

Equipment

Failure rate 0.5%

Equipment

Failure rate 0.2%Test

ReworkTheme Theme

Process flow chart

Test process is lozenge.

Write failure rate of each equipment, if you know.

Make several process maps as many as the number of themes.


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: Divide process and processing machine which is improved into some

working step.

Too many steps lower the efficiency. So, divide into about 5 steps.

Write down working operations.

How to make Process Map

NVA VA

VA

: Show each operation as VA: value-added or NVA: non-value-added.Example for NVA: transportation, storage, test, rework

Below shows a part of lens assemble process.


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: Write down output y and Y (operation result, product status, failure contents)

: write down factor X (environment, setting value, material)

What is the cause of variation (failure)?

What will we change for improving variation (failure)?


Lens breaking by chuck part hit

Transform of chuck part

Falling of lens

Putting lens into frame with opposite way

Offset of the frame location on tray

mis-grasp frame by machine

Offset of the frame location on pallet

Hit mark, transformation of frame

Contamination of frame

Environment of the room

Size accuracy of frame fitting

Size accuracy of lens fitting

Change of chuck air pressure

Chuck part abrasion

Chuck location accuracy

Pallet stopper location accuracy

Contamination of adsorption pipe

Air-cleaning frame and

Apply ion to frame

NVA VA

Put lens into frame

VA


Contamination of air

Shape of air blow mouth

Direction of air blow

Air blow time

Distance of ion applying

Time of ion applying


Contamination of frame tray

Fixing method of frame tray

Vibration of belt conveyor

Shock of belt conveyors stopper

Shock of lifter, moving

Shock of locking tray

Move lens frame

from tray to pallet


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: Classify factor X as C/N/S. (Not need strict classification. Not think too much)

C (can control) X which is easy to adjust or change.

Example: Speed, quantity temperature, pressure,

N (noise): X which is difficult to adjust or change (high cost, low

accuracy)

Example: atmosphere temperature, humidity, operator,

But Is it easy to improve less-educated operator?

Can champion do change of high cost?

SStandard operation procedure: Items in the procedure and commonsense.

Example: cleaning, setting value,

Note) Procedure also made by person. It has many mistake.


: Write down other itemsFailure rate, working time (CT: cycle time)

Issue date, person in charge of process, customer (next process is customer, too)

Narrowing factor X into 10-20 with open technology discussion.


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Completion of Process Map

Y =

Situation of set lens

to frame

CT = 27 secFailure rate = 9.5%

(Falling of lens)

Lens breaking by chuck part hit

Transform of chuck part

Falling of lens

Putting lens into frame with opposite way

Offset of the frame location on tray

mis-grasp frame by machine

Offset of the frame location on pallet

Hit mark, transformation of frame

Contamination of frame

N Environment of the room

N Size accuracy of frame fitting

N Size accuracy of lens fitting

N Change of chuck air pressure

C Chuck part abrasion

C Chuck location accuracy

C Pallet stopper location accuracy

N Contamination of adsorption pipeN Down location accuracy of adsorption pipe

C Size accuracy of lens tray

(Y-axis, Z-axis)

C Lens direction is opposite way on lens tray

C Setting direction of tray is opposite way

Air-cleaning frame and

Apply ion to frame

NVA VA

Put lens into frame

VA


C Contamination of air

C Shape of air blow mouth

C Direction of air blow

S Air blow time

C Distance of ion applying

S Time of ion applying

N Location accuracy of pallet stopper


N Contamination of frame tray

N Fixing method of frame tray

C Vibration of belt conveyor

C Shock of belt conveyors stopper

C Shock of lifter, moving

C Shock of locking tray

C Size accuracy of frame trayC Location accuracy of chuck

C Chuck part abrasion

C Abrasion of frame supporting part of pallet

N Size accuracy of frame

C Size accuracy of pallet

N Change of chuck air pressure

C Location accuracy of frame supporting part of pallet

C Holding force of chuck

C Location accuracy of pallet stopper

S Stacking number of frame tray

Move lens frame

from tray to pallet

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