Definition(s) of QUALITY
Is the produced OUTPUT meeting its specifications - Where did we lost PRODUCT?QUALITY
A machine should only produce product that fully meet its specifications.
When the output does not meet the spec:
When and What reject did occur?
What is
QUALITY
Quality in OEE means: meeting the Specifications
The definition of Quality within OEE is a simple one:
Producing a product that meets ALL specifications,
not by trying more than once but First Time Right.
Specifications
'Specifications' determine 'Quality'
Check your specifications at least for the following characteristics:
Fixed Values
Specifications with a fixed value (no specification-range) have zero tolerance against that value. So [0=0] and [55=55.00000].
Specification Range
Specifications within a range allow a natural variance (or standard deviation) within those limits (>= 1,25 and <= 1,5). Check the correctness, meaningfulness and feasibility of the range as it if often not correct.
Combined standard deviations
The rule is:
All standard deviations brought together in ANY combination
will still produce a correct end-result.
Make sure your quality-specifications meet this rule to prevent sub-optimal settings.
Principles
In terms of OEE, Scrap, Rework and Sub-spec are the same:
It was ‘not first time right’;
therefore it is a loss
- Without applying strict criteria, process control can not be achieved.
Who can afford to have (quality)losses,
can certainly afford to eliminate them
Recommendation
Quality is (far) more than a set of papers...
- Defining scrap-product definitions may reveal poor specifications or poorly testable specifications!
- Good specifications always refer to the needs of the customer!
- We can only ask the operator to produce quality when he is able to check the quality of his labor!
- Who performs a task guarantees its quality
- Who guarantees, is allowed to set requirements
- Who cannot guarantee the quality of its output is obligated to stop the process
- Who detects a downstream failure, returns it to the previous step without correction
- Who makes a mistake solves it
- It is allowed to make a mistake ónce, in order to prevent it from ever re-occurring
- The management guarantees a system that allows the employees to perform its task within its specifications
Principles
Producing only products that meet ALL specifications, First Time Right, is most cost effective.
Rejects are very expensive: all resources have been spent, yet the expected revenues are no longer achievable.
Once output is rejected it starts eating profit from good products
how and how much depends on the the kind of reject
OEE Definitions
OEE Questions
Answer still not found?
If you checked all the sections in the Academy, yet still not found the answer to your question, ask it here.
To help you best, please be as specific as possible and please understand:
We do not want to reply to anonymous questions.