7 QC Tool for Core Electricals

8/16/2019 7 QC Tool for Core Electricals

1/43

Seven QC ToolsSeven QC Tools Problem Solving

Quality Improvement: Problem Solving


2/43

1. Check sheet: A structured form for collecting and analyzing data – A

powerful data recording tool.

2. Histogram: It is a graphical representation of freuency distri!utions.

2.1 "tratification : A techniue to present data in different groups or

categories

7 QC tools

2

. are o c ar : $areto iagram is a tec niue o arranging ata accor ing

to priority or importance and using into a pro!lem sol%ing framework –

&his helps to identify '%ital few( and 'useful many(.

). Cause*and*effect diagram +Ishikawa,-ish!one diagram: &o

find out relationship !etween the causes / effect

).1 0rainstorming : A group techniue for generating new / useful ideas


3/43

7 QC tools & Uses.

. "catter diagram: raphical representation of relationship !etweentwo %aria!les. It can !e !etween cause / effect and two causes

3. raphs and Chart : $ictorial presentation of 4A&A. It helps to

3

manner

3.1 -low Chart : raphical or pictorial way to depict a process. $rocess

seuence can !e represented in a systematic manner.

5. Control charts: raphs used to study how a process changes o%ertime.


4/43

Seven Quality Control ToolsSeven Quality Control Tools

• Pareto Chart• Process flow diagram

• Cause and ffect !iagram

• Chec" sheet


• #istogram

• Control chart

• Scatter diagram


5/43

Pareto PrinciplePareto Principle

$ilfredo Pareto %&'(')&*23+ Italian economist• 2,- of the population has ',- of the wealth

.uran used the term /vital few0 trivial many1 #e noted that

2,- of the uality problems caused ',- of the dollar loss


7 Quality Tools7 Quality Tools


6/43

Pareto chartPareto chart

42 (2-

56-

',-

*&-*6- **- &,,-

5,-

',-

&,,-

&2,-

3,

(,

4,

5,

.

Pareto Chart - Defects.



Punching !rilling Shearing7cess8vality

9aterialShort

Punchrea"

9ar"ing

& 2 3 ( 4 5 6

;o of Cases 42 3& &5 &3 6 3 &- (2- 24- &3- &&- 5- 2- &-

Cum - (2- 56- ',- *&- *6- **- &,,-

3&

&5 &36 3 &

,-

2,-

(,-

,

&,

2,

N o . o f C a s

e


7/43

How to Construct a Pareto DiagramHow to Construct a Pareto Diagram', -

&,, -

1. Total the data on effect of each contriutor & sum these to determine grand total.

!. "e order the contriutors from largest to the smallest

#. Determine the cumulati$e %ercent of total

. Draw & lael the left $ertical a'is.

Contributors

-


8/43


•

Pareto Chart• Process flow diagram


• Chec" sheet


• #istogram

• Control chart

• Scatter diagram


9/43

FlowchartsFlowcharts

=lowcharts

•


10/43

Flow DiagramsFlow Diagrams

? !raw a flowchart for whatever you do

>ntil you do0 you do not "now what you are doing0 you @ust

have a @ob1


)) r war s em ng


11/43

Process Chart SymbolsProcess Chart Symbols

8perations

Inspection

Bransportation

!elay

Storage


12/43

FlowchartFlowchart

cti$it/


Decision

eses

;o;o



13/43

FlowchartFlowchart



14/43

Flow DiagramsFlow Diagrams



15/43

Process ChartProcess Chart

3 t e %

4 % e r a t i o n

T r a n s % o r t

5 n s % e c t

D e l a /

3 t o r a g e

D i s t a n c e

6 f e e t 7

T i m e

6 m i n 7

Descri%tion

of %rocess

1

!

Unload a%%les from truc8

9o$e to ins%ection station

!0

100 ft

Date: -#0-00

nal/st: T;"

;ocation:


16/43



17/43


• Pareto Chart

• Process flow diagram


• Chec" sheet


• #istogram

• Control chart

• Scatter diagram


18/43

CauseCause--andand--Effect DiagramsEffect DiagramsCauseCause--andand--Effect DiagramsEffect Diagrams

Show the relationships between a problem and its possible

causes

!eveloped by Daoru Ishi"awa %&*43+


Elso "nown as F

• =ishbone diagrams

• Ishi"awa diagrams



19/43

Cause and Effect S!eleton"Cause and Effect S!eleton"Cause and Effect S!eleton"Cause and Effect S!eleton"

9aterials Procedures


Qualit/

Prolem

>?ui%mentPeo%le



20/43

Fishbone DiagramFishbone Diagram

9achines9easurement #uman

=aulty testing euipment

Incorrect specifications

Improper methods

Poor supervision

Gac" of concentration

Inadeuate training

8ut of ad@ustment

Booling problems

8ld H worn


ua y

Problem

Processnvironment 9aterials

!efective from vendor

;ot to specifications

9aterial)

handling problems!eficiencies

in product design

Ineffective uality

management

Poor process design

Inaccurate

temperature

control

!ust and !irt


21/43

Cause and effect diagramsCause and effect diagrams

Bo construct the s"eleton0 remember: =or manufacturing ) the ( 9s J

man0 method0 machine0 material0 environment

=or service a lications


euipment0 policies0 procedures0 people


22/43

Cause and effect diagramsCause and effect diagrams

Edvantages

• 9a"ing the diagram is educational in itself

• !iagram demonstrates "nowledge of problem solving team

• !iagram results in active searches for causes

• !ia ram is a uide for data collection



23/43


• Pareto Chart



• Chec" sheet


• #istogram

• Control chart

• Scatter diagram


24/43

Planning for Data collectionPlanning for Data collection

• Ahat uestion do we need to answer

• #ow we will recogniKe J communicate the answers to the uestions )Bells about

reuired data

• Ahat !ata Enalysis tools we need to use• Ahat type of data do we need in order to construct the tool

• Ahere in the process can we get this data

• Aho in the process can give this data

• #ow we can collect data from those people with minimum efforts J chance of


error

• Ahat additional information do we need to capture for future analysis0 reference Jtraceability


25/43

Chec! SheetChec! SheetChec! SheetChec! Sheet

√ √ √ √ √ √ √ √ √ √ √

ShiftsShifts


√ √ √ √ √

√ √ √

√ √ √

! e f e c t B y p e

! e f e c t B y p e


√ √ √ √


26/43

Chec! SheetChec! Sheet

C89P8;;BS LPGEC! GEBI9 PLI8!: 22 =eb to 26 =eb &**'

LPEIL BC#;ICIE;: ob


Integrated Circuits @@@@Capacitors @@@@ @@@@ @@@@ @@@@ @@@@ @@

Lesistors @@

Bransformers @@@@

Commands

CLB @


27/43


• Pareto Chart


• Chec" sheet

• #isto ram



• Control chart

• Scatter diagram


28/43

HistogramsHistograms

E #istogram is a


29/43

3te%s for Constructing a Histogram3te%s for Constructing a Histogram

& Collect the measurements H data

2 Errange H


30/43

4

6

*

'

4

(

4

5

6

'

*

&,

A r e ? u e n c /


2

(

,

&

2

3

2&4 ) 224224 ) 234234 ) 2(42(4 ) 244244 ) 254254 ) 264264 ) 2'4

Diameter

=reuency


31/43

Dot diagramsDot diagrams

Integrated Circuit Response Time (ps)


3 4 5 6

Plant APlant B


32/43

=hat is


33/43


• Pareto Chart



• Chec" sheet


• #istogram• Control chart

• Scatter diagram


34/43

Definition of Control ChartDefinition of Control Chart

Control Chart is a s%ecial t/%e of trend chart used to

detect the s%ecial causes of $ariation in the %rocess.

T/%es of Control ChartsT/%es of Control Charts )

• =or $ariables 0 ie =or the characteristics that can be

) --


• =or Ettributes ) =or characteristics that can be @udges aspass or fail0 go or no)go0 defective or non)defective etc

) n%n% chart % chart c chart u chartchart % chart c chart u chart


35/43

d$antages of using control chartsd$antages of using control charts --

• It is a effective tool to control the process statistically %SPC+

•It helps to detect changes in the process over a period of time

and ta"e corrective action

• It differentiates chance cause variation J assignable cause

variation in the process


process

• It provides information about process capability


36/43

on ro ar son ro ar son ro ar son ro ar s



37/43


38/43


• Pareto Chart



• Chec" sheet


• #istogram• Control chart

• Scatter diagram


39/43

Scatter DiagramScatter Diagram

.



40/43

3catter Diagram3catter Diagram

E Scatter diagram is a graphic presentation of the relationship

between two variables In uality improvement0 scatter diagrams

are usually used to e7plore cause ) effect relationships in the

diagnostic @ourney


e'am%le e'am%le ) E #ydraulic system was tripping for indication

of overload Bhe tripping mechanism is provided as safety

Bhe electronic control circuitry was e7ecuting safety

shut down of the hydraulic system0 with $oltage as a signal

Bhe complaint was more in Summer months from areas that

were close to large bodies of Aater


41/43

8ne of the Probable cause was / Bhe higher Lelative

#umidity causes stic"iness in the system0 leading to increased load and subseuent

tripping1

>ffect>ffect

Bhe diagram clearly shows that as Lelative #umidity increases the sensor reads higher

voltage Bhis causes circuitry to believe that the hydraulic system had e7ceeded it limits Jtrips


•

•

•

•

•

•

•

•

•

••

•

•

••

CauseCause

VoltageVoltage

RelativeRelative

Humidity Humidity


42/43

Bhe graphic nature of the scatter diagram helps a team to see

the relationship between the variables

Bhe patterns of CorrelationBhe patterns of Correlation )

;inear ;inear

5t can e statisticall/ descried as Pearson+s Correlation Coefficient

% It can be strong or Aea" correlation+


Positive CorrelationPositive Correlation ;egative correlation;egative correlation

No Correlation

Non ;inear Non ;inear

CC


43/43


Documents

7 QC Tool for Core Electricals