Presentation on Customer Complaint Elimination

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					CFT / SIT                                            Welcome




                     Presentation
                         on
            Customer Complaint Elimination




                                    Sundaram Clayton Limited   1
                            CFT / SIT                                                                                       1.0 Problem

M6 tap hole leak in CCL Pep casting in engine assembly

                                             Monthly trend of engine leak of CCL Pep castings
                         2000
                                                  1765


                         1600            1489
 No. of Engines leaked




                                1141
                         1200




                         800




                         400




                           0
                                Jan'09   Feb'09   Mar'09   Apr'09   May'09   Jun'09   Jul'09   Aug'09   Sep'09   Oct'09   Nov'09   Dec'09



Inference:
30 to 35 engines per day are reworked at customer end.                                                  Sundaram Clayton Limited            2
CFT / SIT    1.1 Source of Problem




            Sundaram Clayton Limited   3
    CFT / SIT                                     1.2 Importance of the Problem




• Customer Dissatisfaction.


• Leads to engine and vehicle loss (190 Engines and 45 Vehicles

lost during Mar’09)


• Possibility of safety related field failures.


• Single source supplier.




                                                     Sundaram Clayton Limited     4
    CFT / SIT                               1.3 Background of the Problem




• Rework of engines leading to disturbance in engine assembly line.


• Customer target of 100 PPM in engine assembly not achieved.


• Customer to penalize the supplier for rework cost and time for

 every rework and reassembly.




                                               Sundaram Clayton Limited     5
     CFT / SIT                              1.5 Theme & Target



Theme and Target :


To eliminate M6 tap hole leak complaint in CCL - Pep

castings by May’09




                                    Sundaram Clayton Limited     6
   CFT / SIT                                    1.6 Introduction




Team
Members:                                  Department

S Ganesan                 Leader   Production
S Vijay Kumar                      Customer Quality
A Sankar                           Die Management
Syed Irfan                         Production
Anand Ravikumar                    Production
Ravikumar Tantry                   Production

Guide
      Masrur Patel

 Started on ( Week No )            Target ( Week No )
               Wk 1                        Wk 18
                                       Sundaram Clayton Limited    7
 CFT / SIT                                            1.7 Schedule for Improvement


                                         WEEK ( 2007 - 2008 )
         STEP      WHO
                                 1   2     3      4     5       6   7 to 17   18

                             P   b
PROBLEM            Team
                             A
                             P   b
OBSERVATION       SG / SVK
                             A
                             P       b     b
ANALYSIS           TEAM
                             A
                             P                    b
ACTION             TEAM
                             A
                             P                          b       b
CHECK             SG / VK
                             A
                             P                                  b     b
STANDARDISATION    TEAM
                             A
                             P                                        b
MONITORING        SG / SVK
                             A

MANAGEMENT                   P
                   TEAM
PRESENTATION                 A


                                                            Sundaram Clayton Limited   8
     CFT / SIT                                                       2.0 Observation

Product Profile:
Part name            : Crank Case Left

Model                : Scooty Pep - 90CC Engine

Customer             : TVS Motor Company, Mysore

Material             : ADC-12

Net Weight           : 3720 grams

Process              : High Pressure Die Casting

Supplied in          : Fettled and shot blasted condition

Customer req.        : 1000 nos. per day

Casting Machine      : 800 Ton – HPDC

Quality requirements : Pressure Tightness and Blow hole
                       rejection within acceptable level
                                                        Sundaram Clayton Limited       9
       CFT / SIT                                                           2.0 Observation
Observation 1a:
                   Brief description of the Product manufacturing Process
 At SCL                          Ingot Receipt


                                    Melting

                                Metal Treatment         Die servicing

                            High pressure die casting


                            Post casting operations


                                 Shot blasting


                              M Seal application


                             Despatch to TVSM for
                            machining and assembly




                                                              Sundaram Clayton Limited       10
         CFT / SIT                                                                     2.0 Observation

Observation 1b:
                     Brief description of the Product manufacturing Process
 At TVSM                                                         Internal defects( Blow holes ) revealed in
                                       Painting                  this process

                                       Machining         Not OK
     Casting soundness (Leak)
     revealed in this process                OK
                                    Leak testing for             Rejection
                                                        Not OK
                                     oil pump area

                                              OK

                                     Partial Engine
   M6 tap hole Leak                    assembly
   revealed here
                                     Leak testing in                     Rework
                                     Gear case area       Not OK

                                              OK
    Purpose of leak
        testing :                      Full Engine
   Any leak from the                    assembly
  M6 tap hole will leak
     into the cover
  variator side which                Vehicle assembly
  creates rubber belt
          slip .
                                                                        Sundaram Clayton Limited         11
      CFT / SIT                                                2.0 Observation

Observation 2:

Understanding of phenomena - Leak :



                                                       Air passing
                                                        passage
                                                                  Leak from this
                                                                   M6 tap hole




Leak testing at Engine assembly:
• Leak testing is carried out after partial
  assembly of the engine parts with casting.
• Air at 0.3bar pressure is passed through the
  oil adapter hole and circulated into the gear
  case area.
• Any leak will be indicated by the digital
  indicator.
                                                  Sundaram Clayton Limited         12
      CFT / SIT                                                             2.0 Observation
Observation 3 : Casting




                                                                              M6 core pin
                                                                           In the moving die




Top core pin
  in the die




Oil adapter hole formed by the top core pin and M6 tap hole formed by a core pin in moving die


                                                               Sundaram Clayton Limited       13
     CFT / SIT                                                        2.0 Observation

Observation 4 : Process parameter
    Process Parameter Standard                           Operation Standard




                                        QCPC




Inference: QCPC, OS , PPS available for this component
                                                         Sundaram Clayton Limited       14
        CFT / SIT                                                                             2.0 Observation

Observation 5: Machining
                                                         Oil plug hole                   M6 tap hole




                                              Before         After       Machining
   S.No     Dimension                        machining     machining     allowance

    1       Oil plug hole diameter maximum    13.5mm        14.5 mm      0.5 mm / side

    2       Oil plug hole diameter minimum    10.5 mm       14.5 mm      2 mm / side

    3       M6 tap hole diameter maximum       4 mm          5 mm        0.5 mm / side
                                                                          0.75 mm /
    4       M6 tap hole diameter minimum       3.5 mm        5 mm            side

Inference: More machining allowance

                                                                                Sundaram Clayton Limited        15
       CFT / SIT                                                                 2.0 Observation

Observation 5:
Leak testing at Engine assembly:
• Leak testing is carried out after partial assembly of the engine parts with casting.




        Before sub-assembly              After gear assembly            After gear case assembly




Inference:
3 to 3.5 % of the castings are found to be leaking at this stage.            Leak checking
                                                                    Sundaram Clayton Limited       16
       CFT / SIT                                                                2.0 Observation

Observation 6:

Leak testing at Engine assembly:

• Leaked castings are salvaged using Locktite solution and re-issued to engine
  assembly.


 Leak testing Parameters at engine assembly
 Test pressure                -         0.3 Bar
 Charging time 1              -         2 sec
 Charging time 2              -         1 sec
 Balancing time               -         3 sec
 Detection time               -         5 sec
 Allowable leak limit         -         100 pa           Location of application of
                                                         Locktite for salvaging




Inference:
3 to 3.5 % of the castings are salvaged using Locktite
                                                              Sundaram Clayton Limited            17
      CFT / SIT                                                                 2.0 Observation

Observation 7: Assembly requirement

                                                    Oil plug hole             M6 tap hole




 1.   Oil plug area thru hole drilled for 30mm with 14.5mm dia and tap length
      is 16mm ( No. of threads – 11 )
 2.   Out of 11 threads mating plug effective contact is only 5 threads.
 3.   M6 tap hole area drilled for 20mm with the tap length of 15mm
      ( No. of threads – 15 )
 4. Out of 15 threads mating screw effective contact is only 10 threads
                                                                 Sundaram Clayton Limited         18
      CFT / SIT                                                             2.0 Observation

Observation 8:
Radiography results of defective sample:




 1.   Thick mass of 7.7mm available between oil plug hole and M6 tap hole
 2.   Thick mass of 35mm available below M6 tap hole.
Inference:
X – Ray images of the defect location shows shrinkage in all the castings below the M6 tap hole
area
                                                               Sundaram Clayton Limited       19
       CFT / SIT                                                                                                                               3.2 Analysis

Defect matrix :

                                                                          Defect Matrix
  Part Name: Crank Case Left Pep




                                                                                                                                                Hole ovality
                                                                                                         White Rust




                                                                                                                                                                                                              Black stain
                                                                      Cold Shut




                                                                                                                                                               Blow hole
                                               Shrinkage




                                                                                                                                   Soldering
                                   Inclusion




                                                                                                                                                                           damages

                                                                                                                                                                                      Prefilling

                                                                                                                                                                                                   Chip off
                                                           Porosity




                                                                                                                      Peel off




                                                                                                                                                                             Dent /
                                                                                  Crack

                                                                                           Bend

                                                                                                  Drag
                           Leak
  Defect


  Opn. description

  Melting

  Die maintenance

  Die casting

  Fettling

  Packaging

  Despatch

                                  Least corelation                                        Strong corelation




                                                                                                                                 Sundaram Clayton Limited                                                       20
      CFT / SIT                    3.2 Analysis

Defect matrix : Die casting




                              Sundaram Clayton Limited   21
      CFT / SIT                                                                                                                                                    3.2 Analysis

Defect matrix : Die maintenance

                                         DEFECT MATRIX - HIGH PRESSURE DIE CASTING




                                                     Non clearance




                                                                                                                                                                                                                                 Surface Finish
                                                                                                                                         Dimensional




                                                                                                                                                                    Hole ovality




                                                                                                                                                                                                                    Heat Check
                                                                     Shrinkage



                                                                                            Cold Shut




                                                                                                                                                                                   Blow hole
                                                                                                                                                       Soldering
                                                                                                                                           variation
                                                                                 Porosity




                                                                                                                                                                                                         Chip off
                                                                                                                              Peel off




                                                                                                                                                                                               Blister
                                                                                                        Crack

                                                                                                                Bend




                                                                                                                                                                                                                      mark
                                              Leak




                                                                                                                       Drag
         Process /
                           Parameter
         Operation



                     No damages,dent &
                     Under cut in core pins

                     Blue Matching


                     Nitriding


           Die    Cooling line checking
       Maintenanc
                  Cooling pipe de-
            e
                     scaling

                     Air Vent Cleaning


                     Polishing


                     Ejector pin assy.




                                                                                                                                            Sundaram Clayton Limited                                                                              22
       CFT / SIT                                                         3.2 Analysis

4M Conditions - Leak :


                                       Leak in Casting



        MAN                   MACHINE                 METHOD                     MATERIAL




• Cooling lines not      • Less pressure build    • Improper design of       • Wear out of core
  checked                  up time.                 Chill vent                 pins

                         • Metal temperature      • Gating design

                         • Less intensification   • Casting and
                           pressure                 machining design

                         • Less cast pressure




                                                                    Sundaram Clayton Limited      23
      CFT / SIT                                                                         3.2 Analysis

4M Conditions - Leak :

               Phenomena                       Leak through M6 tap hole

        4M
               Process Parameter                          Present control               Spec        Actual


                                                                                      Opr to be     Opr
    Man        Checking of cooling line        Checked during die PM                 certified as certified
                                                                                         SL1      as SL 1
               Less pressure build up time. Patrol inspection for every 2 hours         60 ms       59 ms
                                                                                       640 - 660
               Metal temperature               Patrol inspection for every 2 hours                 655 deg C
                                                                                        deg C
    Machine
                                                                                       280 - 300
               Less intensification pressure Patrol inspection for every 2 hours                    295 bar
                                                                                         bar
                                                                                       640 - 660
               Less cast pressure              Patrol inspection for every 2 hours                  652 bar
                                                                                         bar
                                                                                                    Found
                                               Checked during PM of die and           As per FO
    Material   Wear out of core pins                                                                within
                                               certified in First off inspection        spec
                                                                                                     spec
                                               Checked durign design review and       0.6mm CV
               Improper design of chill vent                                                       0.65mm
                                               validated during die proving           thickness
                                                                                                   Found as
    Method                                                                             AS per
               Gating design                   Checked during die design review                       per
                                                                                      design std
                                                                                                   standard
                                               Checked during product design
               Casting and machining design                                                        Not done
                                               review
                                                                                   Sundaram Clayton Limited    24
        CFT / SIT                                                                 3.2 Analysis

Analysis:
                          Leak from M6 tap hole



                      Interconnection between
                    Oil plug hole and M6 tap hole




  Presence of shrinkage                       Shrinkage holes between
  between the two holes                       the two holes opened out



   Thick mass 7.7mm                          Excess material removal
between M6 and oil plug                     during machining operation
 hole and 30mm below                          ( 2.2m at Oil plug hole )
      M6 tap hole



                                                  Machining process design
  Product design




                                                                             Sundaram Clayton Limited   25
           CFT / SIT                                                                      3.2 Analysis

 M6 Tap hole leak :
 Root cause : Product design

                                                                         Machini
                                                                            ng
                                                Before        After      allowan
      S.No    Dimension                        machining    machining       ce
                                                                         0.5 mm /
       1      Oil plug hole diameter maximum    13.5mm       14.5 mm       side
                                                                         2.2 mm /
       2      Oil plug hole diameter minimum    10.5 mm      14.5 mm       side

       3      Oil plug hole depth               Thru hole    Thru hole      ---
                                                                         0.5 mm /
       4      M6 tap hole diameter maximum       4 mm         5 mm         side
                                                                         0.75 mm /
       5      M6 tap hole diameter minimum       3.5 mm       5 mm          side

       6      M6 tap hole depth                  20 mm        20 mm         ----


 1.        Already machining stock of 0.5mm only available on the maximum side and
           increasing the diameter in the minimum side will result in core pin breakage
 2.        Also increasing the M6 core pin depth more than 20mm also will result in core
           pin breakage.

Inference: Counter action on product design is not feasible
                                                                                     Sundaram Clayton Limited   26
        CFT / SIT                                                         4.1 Action Taken




Action – 1:                                                      Demerits:
Modify machining at Customer end to                                           Nil
eliminate unwanted machining at oil
plug hole area
                  Operation
  S.No           Description             Before       After
                                         30mm thru
    1     Oil plug hole Drill depth        hole      12 mm
    2     Oil plug hole Drill diameter    14.5mm     14.5mm
          Oil plug hole Step Drill
    3     depth                            -------   thru hole
          Oil plug hole Step Drill
    4     diameter                         -------   10 mm
    5     Oil plug hole Tap depth         16 mm      10 mm
    6     Oil plug hole Tap                M 16        M16
    7     No of tap                         11          6



Merits:
M6 hole leak after assembly eliminated.
                                                                       Sundaram Clayton Limited   27
         CFT / SIT                                           4.1 Action Taken




Action – 2:                                         Demerits:
Modify machining at Customer end to                              Nil
eliminate unwanted machining at M6
tap hole area

                 Operation
  S.No          Description        Before   After

   1      M6 hole Drill depth      20 mm    13 mm

   2      M6 hole Drill diameter    5 mm    5 mm

   3      M6 hole Tap depth        15 mm    11 mm

   4      Oil plug hole Tap         M6       M6

   5      No of tap                  15      11




Merits:
M6 hole leak after assembly eliminated.
                                                          Sundaram Clayton Limited   28
CFT / SIT




      Before                                         After




                                    Machining eliminated
              Machining done        and no. of taps 6 nos
            and no.of taps 11 nos                       Sundaram Clayton Limited   29
     CFT / SIT                                                                5.1 Check



Results after implementing machining change at customer end:


                                                   Machining


                 Qty Machined                      45,000 nos


                 % Leak in Engine assembly              0




Inference :

• No leak found after implementing the machining change at customer




                                                            Sundaram Clayton Limited      30
  CFT / SIT                             4.3 Cost Analysis




Budget for correction: Rs. 2500 to change

to step drill




                            Sundaram Clayton Limited        31
   CFT / SIT                                           5.2 Benefits




Productivity
No change in in-house productivity




Quality

Zero Engine assy. leak after machining and assembly.




                                     Sundaram Clayton Limited     32
    CFT / SIT                                               5.2 Benefits




Cost:

No increase in manufacturing cost.
Saving rework cost – Rs. 90,000/ annum
Indirect benefits:

   • Cost due to Engine loss eliminated (@ Rs.1000/ engine)

   • Cost due to vehicle loss eliminated (@ Rs.3000/ vehicle)



                                          Sundaram Clayton Limited     33
   CFT / SIT                                              5.2 Benefits




Morale
• Morale improved as customer complaint eliminated.




Safety
• No change.




                                        Sundaram Clayton Limited     34
        CFT / SIT                                                         6.1 Standardisation (5W1H)



S. No           WHAT                   WHY                     HOW                 WHERE        WHO    WHEN
              (ACTIVITY)            (NECESSITY)               (METHOD)            (LOCATION)   (RESP.) (FREQ.)




 1        Modify oil plug hole   To eliminate       By changing the drill      Customer        TVSM      A/O
          machining depth        shrinkage          bit and by changing
          and tap depth as per   connectivity       the machining
          the ECR                between oil hole   program
                                 and M6 hole

 2        Modify M6 tap hole     To eliminate       By changing the drill      Customer        TVSM      A/O
          machining depth        shrinkage          bit and by changing
          and tap depth as per   connectivity       the machining
          the ECR                between oil hole   program
                                                                               Customer        TVSM      A/O
                                 and M6 hole
          Update modified dwg Standardization       Update in machining                                  A/O
 3                                                                             Customer        TVSM
          and release ECO                           dwg




                                                                            Sundaram Clayton Limited        35
      CFT / SIT                                            6.1 Standardization
Product design standardized using ECR- (ECR no: 507901 , dt . 08.05.09 ).
                                                                 Tap - M16 x 1.5, 10mm depth
                                                                 Drill – Ф 14.5, 12mm depth
                                                                 Drill – Ф 10 thru’
                                                                 Spot face as existing
                                                                 Mouth chamfer 1 x 45o




                                                        Sundaram Clayton Limited         36
 CFT / SIT                                            1.7 Schedule for Improvement


                                         WEEK ( 2007 - 2008 )
         STEP      WHO
                                 1   2     3      4     5       6   7 to 17   18

                             P   b
PROBLEM            Team
                             A
                             P   b
OBSERVATION       SG / SVK
                             A
                             P       b     b
ANALYSIS           TEAM
                             A
                             P                    b
ACTION             TEAM
                             A
                             P                          b       b
CHECK             SG / VK
                             A
                             P                                  b     b
STANDARDISATION    TEAM
                             A
                             P                                        b
MONITORING        SG / SVK
                             A

MANAGEMENT                   P
                   TEAM
PRESENTATION                 A


                                                            Sundaram Clayton Limited   37
    CFT / SIT                                                   7.0 Conclusion



Learning's:


1. More machining of casting will leads to opening of shrinkage and will

  create connection between two machining holes.

2. Thick mass between two nearby machining holes to be avoided in the

  product design stage itself




                                                  Sundaram Clayton Limited       38
  TIME FOR
INTERACTION
CFT / SIT




            Thank you


               Sundaram Clayton Limited   40

				
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Description: Presentation on Customer Complaint Elimination