How to define c=0 Reject Rates

Elsmar Forum Sponsor

Sidney Vianna

Post Responsibly
Staff member
Admin
#2
Re: c=0

You inspect a lot, based on a sample. The only acceptance criteria for the lot is when you find zero defects in the sample. One (or more) defective products must lead to the lot being rejected.
 
T

The Capt - 2011

#3
Re: c=0

But 1 defect in the sample is not nessecarily indicative of the rest of the lot being "contaminated"
 

Sidney Vianna

Post Responsibly
Staff member
Admin
#4
Re: c=0

You asked for the definition. If you don't like it, it is not my fault.

You can always skip sampling and revert to 100% inspection....
 

bobdoering

Stop X-bar/R Madness!!
Trusted Information Resource
#5
Re: c=0

But 1 defect in the sample is not necessarily indicative of the rest of the lot being "contaminated"
Conversely, no defects in the sample is not necessarily indicative of the rest of the lot being "clean". It is called sampling error. That is why it only works if you are looking for statistically significant reject events. One bad part out of 5000 will slip under sampling radar more often than not.
 
T

The Capt - 2011

#7
Re: c=0

You asked for the definition. If you don't like it, it is not my fault.

You can always skip sampling and revert to 100% inspection....
Never said I didn't like it....Why so defensive? Just trying to bring another point of view, to stir the conversation.........GHEEEES
 
T

The Capt - 2011

#8
Re: c=0

One defect is evidence that there could be more. Under a c=0 plan, the lot is rejected. Usually sorting happens after that.
That's what I was thinking but defined in Jurans it sounds different. Section 46.41 5th addition.
 
T

The Capt - 2011

#9
Re: c=0

Conversely, no defects in the sample is not necessarily indicative of the rest of the lot being "clean". It is called sampling error. That is why it only works if you are looking for statistically significant reject events. One bad part out of 5000 will slip under sampling radar more often than not.
True, even in a lot of 8 with a sample of 7 a defect can slip through.
 
E

EdZachary

#10
How about this wrinkle ... what would you do?

Total Population 20,000
Customer takes deliver of 396 ... finds 2 failures
C=0 Sampling of 315 units yields one failure (.040 AQL)
Common sense would dictate sorting / screening, but that also takes time.
Estimating number of potential defects in remaining population?
What is probability of more than estimated failures in balance of population?
 
Thread starter Similar threads Forum Replies Date
A Define timeline for Major and Miner Audit finding General Auditing Discussions 4
T How do you define your Hazards? <a Risk Management discussion> ISO 14971 - Medical Device Risk Management 16
M Define voltage and frequency to perform tests 61010-1 and 61326-1 for CE certification CE Marking (Conformité Européene) / CB Scheme 4
I Sampling processes - Who must define the AQL level? AQL - Acceptable Quality Level 9
V Who should define and own the Design and Development Plan and how to maintain the updates and revisions. ISO 13485:2016 - Medical Device Quality Management Systems 2
S API Spec Q1 - How to define Management Representative competency for QMS Oil and Gas Industry Standards and Regulations 12
M How To Define ISMS (information Security Management System) Scope IEC 27001 - Information Security Management Systems (ISMS) 18
K How to define Expected life service life of medical device Other Medical Device Related Standards 4
S How to Define Importers under EU MDR / Brexit EU Medical Device Regulations 3
M Should Potential Customer Complaint Outcome Define Registrar NC Rating? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 8
K ISO 9001:2015 clause 9.2.2 a. - Define the audit criteria and scope Internal Auditing 2
Q QI Macro Histogram - Can someone define *sorted data*? Capability, Accuracy and Stability - Processes, Machines, etc. 7
H How to define Root Cause when some points are out of control chart Statistical Analysis Tools, Techniques and SPC 6
I How do you define Risk (Medical Device)? ISO 14971 - Medical Device Risk Management 30
M SOP or template for a study to Define Storage Conditions of Orthopaedic Implants EU Medical Device Regulations 3
D Definition Client - How does the government define their clients? Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 1
alonFAI How to define a Risk Based Approach for Supplier Management per ISO 13485:2016 ISO 13485:2016 - Medical Device Quality Management Systems 1
G How to define the scope of QMS as per ISO 9001:2015 ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 21
R How to define QMS certification scope statement? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 11
R Review of "Key Data" for contract labs, but SOP doesn't define "key data". Problem? Pharmaceuticals (21 CFR Part 210, 21 CFR Part 211 and related Regulations) 2
G Procedure to define Signing Authority for Procurement Limits ISO 13485:2016 - Medical Device Quality Management Systems 2
P Can a company define new quality standards for special industry ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 2
L Are there any requirements to define barcode requirements ? Misc. Quality Assurance and Business Systems Related Topics 2
X How to define Calibration Acceptance Criteria General Measurement Device and Calibration Topics 3
H ISO 17025 - How to define a "Test Equipment" ? ISO 17025 related Discussions 2
J Where do you define Internal Auditor qualifications? Internal Auditing 9
V Is there an approach to define the "must 'or' should" in supplier audits? US Food and Drug Administration (FDA) 2
T Internal Audit - How to define the Importance of Departments and Processes Internal Auditing 8
T Help me understand how to define Processes ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 40
L How to define R & D Receiving (Incoming) Inspection Plan Design and Development of Products and Processes 18
B How to define and implement Configuration Management Document Control Systems, Procedures, Forms and Templates 5
C How to Define and Document Controls of Outsourced Processes Food Safety - ISO 22000, HACCP (21 CFR 120) 5
S Please help me define training requirements for a Career in Regulatory Affairs 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 2
K How to define the Acceptances Criteria for all equipment? Manufacturing and Related Processes 7
L Definition Program - How do you define Program with regard to ISO 9001? Definitions, Acronyms, Abbreviations and Interpretations Listed Alphabetically 3
A Supplier Evaluation SOP - How do I Define Major and Minor Suppliers? Supplier Quality Assurance and other Supplier Issues 14
Q Where to define Authorities and Responsibilities in Documentation? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 1
J Define Energy Used/Delivered - Applicable to Electrical or Mechanical Power or both? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 1
R 820.50 (A) (2)Define the Type and Extent of Control to be exercised over Vendor Misc. Quality Assurance and Business Systems Related Topics 5
A Where to define Process Tailoring Form used in CMMI in the ISO 9001 Quality Manual? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 5
Q Criteria to define QMS processes in ISO/TS 16949:2009 IATF 16949 - Automotive Quality Systems Standard 23
S How to define New Equipment? Device is Returned, Refurbished or Repaired Misc. Quality Assurance and Business Systems Related Topics 3
C Controlling Documents: Beyond the standard, how do we truly define what to control ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 9
C How to define Process Special Characteristics (SC) FMEA and Control Plans 4
kedarg6500 What is the meaning of "define/defined" in ISO 9001? ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 19
Crusader Local Control Document procedure....define it or not? Document Control Systems, Procedures, Forms and Templates 24
M Excel Templates for Plan & Define Phase in NPI Process for Tire Manufacturer Excel .xls Spreadsheet Templates and Tools 1
R Define Data from Taguchi to Response Surface Methodology in Minitab Using Minitab Software 2
K How to define PVC Pellet Quality Manufacturing and Related Processes 8
J How to define a Product's Realization Process and Scope ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 8

Similar threads

Top Bottom