Embed Size (px)
Citation preview
Webinar
January 21, 2015
Presenter: Phil Mistretta, Metrology Manager
As-Found: Out-of-Tolerance ….
…now what do I do?
What’s the Big Deal about Out-of-Tolerance Equipment?
• There is additional risk to all products on which it was used
• The potential risk can lead to dangerous situations and additional business costs
• So where do you turn for guidance?
Objectives
1. Practical guidance on evaluating Out-of-Tolerance conditions through a systematic approach to help concentrate your efforts to identify those areas that will need further analysis.
2. Key elements in developing a Measurement Assurance Program which will make OOT evaluations quicker and easier
BonusGood Metrology Practice (GMetP) tips
Calibration
• Lets define a few things ……
• Calibration is ... a comparison to a metrology laboratory standard of known performance and documented uncertainty, to the unknown behavior of a unit submitted for calibration
• When it fails expected performance, non-compliant, Out-of-Tolerance (OOT)
Traceability
Statement of Compliance
Out-of-Tolerance Investigation
1. What – Review the calibration certificate in detail
2. When – Determine the time frame that needs to be examined
3. Where – Determine where the instrument was used
4. How – Determine what the instrument was to measure
5. Mechanics / mathematics of the evaluation
What
• What Functions / Parameters?• What Range?• What test point?• How many OOT Test Points?• Was the entire Range OOT?• Was the a linearity issue?• Was it just the Zero point?• Was it just the Full Scale point?• Are there any test point at the limits?• Are there any test point just in-side the limits?
What - Example
Range: -10°C to 160°C
Accuracy: ± 0.06°C
OOT: 2 points, 100°C and 150°C
When
• What time frame do I need to investigate?• When was it last KNOWN to be in-tolerance?• Is there any measurement data to support a shorter time
frame?• Are there any Preventative Maintenance documents?
• GMetP Tip• Document, document, document• Process control charts• Mid-cycle checks, inter-comparisons, cross-checks• Calibration Interval Change Policy• ……..Document
When - ExampleLast know In-Tolerance Date: As-Left date of Previous CalibrationFrom: January 5, 2014To : January 15, 2015
GMetP TipDocument any time the unit is removed from service
Where
• Where was the unit used during the time frame?• What department?• What area?• What product line?
• GMetP Tip• Area-ID-Location• Rack mounted equipment does not walk• 5S / Visual Management – shadow boards• Tool Cribs – Sign-Out, Sign-In• Electronic tracking, Bar codes, RF ID tags, etc• Work Station or Bench assignments
Where - Example
• Where: the unit was used in the Thermometry Lab Only
How
During the time frame in question, in all locations where it was used, for the OOT Parameters, Ranges Test Points…
• Check end user procedures?
• Check work Instructions?
• Check Engineering Specifications?
• Check Process Documentation?
• Check All Revision of the documents?
How - Example
• This unit is called out by Calibration Procedure CP-0303 R3, and CP-0310 R0
• CP-0303 R3 states this unit is used to monitor a 25°C Bath
• CP-0303 R3 is dated 1/1/2010
• CP-0310 R0 states this unit is used to monitor a 100°C Bath
Analysis
• We know:– What
– When
– Where
– How
• Assessment of error – did the error impact product?
• Magnitude and Direction of error
• Error Impact on Product
Analysis - Example
We know:– What: All reading above 100°C were OOT
– When: 5 Jan 2014 to 15 Jan 15
– Where: Thermometry Lab Only
– How: 100°C Bath
Magnitude : 0.04°C
Direction: Thermometer read too high
Analysis - Example
We need to know what the product would have read at 100°C • Since the UUT was reading too
high, all products readings will also be too high, by this amount
• Since all reported product readings were too high, we must subtract the UUT’s error from the Products reported readings to get the products actual behavior at 100°C
• Now check the corrected Product indication against the Process tolerances
• Did it still Pass?• Did it now Fail? • Repeat for all product meeting
our investigation criterion.
Measurement Assurance Programs1. R&D Product Specifications2. Manufacturing Process & Documentation
- Tip: Identify Critical Measurements- Tip: Set Warning Tolerances
3. Selection of Suitable Test Equipment– Tip: Select single parameter vs. multifunction– Tip: Smart Accuracy Ratios
4. Quality Control Program- Tip: Process control charts for critical measurement- Tip: Mid-cycle checks, cross checks
5. Preventative Maintenance Program– a) Regular Calibration– b) Calibration with As-found / As-Left & Uncertainties– c) Calibration Interval Adjustment Policy
Summary• Out-of-Tolerance Statements• OOT Investigation
• What• Where• When• How• Mechanics and Mathematics
• Measurement Assurance Program Elements• R&D• Equipment Selection• Process & Documentation • Quality Control• Preventative Maintenance• Equipment Control• Product Traceability
