Fault data spectrum an important quality tool
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The document introduces the Fault Data Spectrum (FDS) as a tool to continuously monitor the effectiveness of corrective actions in order to prevent faults from reoccurring in products, thereby protecting organizational reputation and customer satisfaction. It explains fault classifications, corrective action processes, and the importance of timely responses to faults as a means to maintain quality standards. Additionally, the FDS tool aids in the identification, analysis, and resolution of faults across different product categories, ensuring systematic improvement and accountability within organizations.
Fault data spectrum an important quality tool
- 1. 1 Title Fault Data Spectrum:FDS an important tool to monitor effectiveness of corrective actions in Field before it is too late By K Umesh
- 2. 2 Manuscript The Objective is to introduce a tool to monitor the effectiveness of Corrective Actions on a continuous basis so that the “Faults” cease to appear . If the “Faults” still appear after the Corrective Actions, it is visible early so that the Organization regroup the teams together to start another Cycle of “PDCA” with a proper root cause analysis and help with a fully Effective Corrective Action. The Corrective Actions may be taken on a Production or a Field Problem where the impact is External and deep and can cause substantial loss of repute to the Organization at the cost of a disenchanted Customer. Brief Definition Of Fault :- A “Fault” can occur in a Process, Component or a Product if one or more of the parameters deviate beyond permissible limits of Design Intent. A Process Fault can occur due to high dispersion and is controllable with control on the Process and Machine Parameters. The outcome of a Process Fault will be a Faulty Product ultimately. A “Fault” can also occur if the desired output is not achieved with the intended Design Input. A Fault due to Design inadequacy will be highly repetitive in nature.
- 3. 3 All “Faults” are not similar in Impact with few in small nos. having a catastrophic effect on the Product e.g. Safety Faults. While there may be others in large nos. but not noticed by a Normal Customer but only by a “Highly Discernible Critical Inspector”. Such Faults do not have any impact on the Functional or Reliability aspect & If they are overcome through simple Process or Material change, it is pragmatic. Thus, Faults need “Classification”. “Acceptance Quality Levels-AQL” can be decided for different categories of Faults based on the Criticality of the Product. A Critical Healthcare equipment will have a very rigid AQL. See example below where the Faults are classified, coded and can be traced in the Field later. The “Fault Codes F1 ..F13” shown are derived during development stages but will be used in Field later. Part Name Part No Date Supplier Classification K A B C 1. Safety F1 a) Poor Weld Joints X F2 b) Missing :Part Missing X F3 c) Sharp Edges X F4 d) Tube Crack X F5 e) Weld Cracks X 2. Functional F6 a) Weld Discontinuity X F7 b) Uncoverage of Paint /Coating X F8 c) Paint peel off X F9 d) Rust formation X F10 e) Bubbles X F11 f) Fastening Points - No Thread / Oversize /Undersize X 3. Minor / Appearance F12 a) Poor Surface Finish X spot, pit marks, streak mark, scratches, flashes, burr F13 b) Dirty - Difficult to clean X - Easily cleanable X d) Surface Scratches - Severe X - Minor X FAULT CLASSIFICATION Chassis Frame Assy Document No xx/xxxxxx/001 xxx-xx-xx Revision R0 Fault type Fault Description DD-MM-YYYY Prepared By----> xxxx/yyyyy xyz, ABC Approved By----> zzzzzz Fault Codes
- 4. 4 Concept of “Fault Data Spectrum-FDS” :- In the event of a Field Complaint, PDCA Cycle is used for Corrective Actions. “PDCA Cycle should be Short & Effective” otherwise it will require another Cycle Causing delays & bad Customer Perception. Start Project Collect Data Identify Process & Set Target Analyse Problem & Determine Cause Decide On Corrective Actions Implement Solution Review & Assess Results Standardise Solution Conclude Project Plan Do Check Act
- 5. 5 Customer perception gets affected if the Corrective Actions are not effective and that is monitored through “Fault Data Spectrum”. Fault Data Spectrum Tool “FDS-Fault Data Spectrum” is a tool consisting of “Fault Classifications” with a “Positrol – Positive Control Plan” in a Grid Structure. The Tool has an FDS sheet and a Positrol sheet. The FDS sheet contains Faults Codes & Product Sr.Nos. In each column it has color shades showing the implementation of Actions with reference to the Manufacturing Month or Product Sr.No. After the implementation of the Corrective actions the Faults should taper drastically or become zero.
- 6. 6 FDS of a New Product – an Outdoor Application Vacuum Cleaner with Fault codes & upto 3000 nos. sold. For Faults F1 and F2, a corrective action was taken after Product No.226 but the action was only partially effective as it did not eliminate complaints altogether. Only after another PDCA cycle at Product No.326, the Faults did not recur in 2700 Products sold. But additional PDCA Cycle has taken time equivalent of 100 Products manufactured and this is a costly lapse for the company. Faults 3,4,5,7 & 8 have shown first time right corrective actions. Final Effective Solution 80 41 13 5 6 3 5 4 3 475 ~ 3000 400 ~ 475 375 - 400 351 - 375 326 - 350 1 301 - 325 1 1 276 - 300 1 251 - 275 1 1 226 - 250 1 3 201 - 225 1 1 1 1 176 - 200 6 1 151 - 175 4 1 2 1 1 126 - 150 7 2 2 2 101 - 125 2 1 1 1 76 - 100 13 2 1 1 51 -75 1 1 1 1 26 - 50 1 2 1 1 0 - 25 5 1 F1-Fault 1 F2-Fault 2 F3-Fault 3 F4-Fault 4 F5-Fault 5 F6-Fault 6 F7-Fault 7 F8-Fault 8 xxxx not opening with yyyy xxxx not opening with zzzz xx/yy not opening from inside xx/yy not opening from outside xxxx noise (abcd loose) nnnn failures xxxx switch failure White dot markTotal Production Batch / Fault Types Containment Action Interim Action-not fully effective Fault Data Spectrum for XXXX Assy
- 7. 7 Corrective Actions are described in Positrol sheet :- Variation in xx Capacity: Higher All xxx above 180grams used 259 onwards Intermittent operation in rainy condition due to water entry -Hot glue application for connectors -Wrapping of xxxx motor and connector to avoid water ingress. 315 onwards Variation in xx Capacity: Higher All xxx above 180grams used 259 onwards Intermittent operation in rainy condition due to water entry -Hot glue application for connectors -Wrapping of xxxx motor and connector to avoid water ingress. 315 onwards F3 xx/yy not opening from inside Bend length of xxx bigger link is found insufficient to hold the link even if the clip is unlocked. 2. The xxx link bend length increased by 2 mm 259 onwards F4 to F9 F2 xxxx not opening with zzzz Similar method Implemented On Status F1 xxxx not opening with yyyy Fault Code Fault Description Analysis Corrective Actions
- 8. 8 Example of a domestic Hair dryer which has 5 Major Faults. For Fault1 , the corrective action was effective only in 3rd Cycle. Final effective solution Intrim action-Not fully effective Intrim action- Not fully containment action 30 24 3 1 1 1 375 - 10000 351 - 375 326 - 350 1 301 - 325 276 - 300 1 251 - 275 226 - 250 2 1 201 - 225 1 176 - 200 1 151 - 175 2 126 - 150 3 101 - 125 3 76 - 100 2 2 1 1 51 -75 5 26 - 50 0 - 25 3 1 Prod. Batch Fault 1 Fault 2 Fault 3.1 Fault 3.2 Fault 3.3 Switch operating but lever not moving Solenoid driver failure Driver fault in pcb Reverse lamp driver failure Fault Data Spectrum for Hair Dryer Total Fault types Switch not / intermittently working Positrol-Hair Dryer Fault Code Fault Description Analysis Corrective Actions Implemented OnStatus Flashes in switch cap assembly Flashes in switch cap removed 001 Suction cup sticking to the switch bkt Retainer design modified 314 Switch intermittent due to black deposition after around 1000 cycles Switch make changed to xyz 384 Detent plate got bend 1.100% hardness checking of detenet pin and bush. 2.Torque mark on detent plate screw to be ensured @ incoming stage 347 Solenoid pin touching to PCB housing Pokayoke implemented @ supplier end for complete pressing of solenoid pin 347 F3.1 Solenoid driver failure Driver Optocoupler failure in xxxxx PCB Defective part sent to supplier for analysis 100% diagnostics checking @ supplier end 347 F3.2 Driver fault in pcb lead bridging positive signal track and Dig 1 output pin short 100% diagnostics checking @ supplier end / FI 347 F3.3 Reverse lamp driver failure Reverse Reed switch damage 100% diagnostics checking @ supplier end /FI 347 F1 Switch not / intermittently working F2 Switch operating but lever not moving
- 9. 9 Conclusions :- “Fault Data Spectrum” is a very effective tool to monitor the effectiveness of corrective actions. It can detect early and initiate another action without loosing much time and make a solution permanent. “Fault Data Spectrum” and “Fault Classification” are linkable and can take the actions upstream at Tier 1, Tier 2 and Tier 3 supplier level. They can be used during Development Phases and each Failure encountered in Alpha, Beta or Pilot Production can be seen for Closure effectively.