Errors of Measurement

To ensure the quality of a product, errors of measurement is very important, as test cases are executed at various levels defects if found any in the tested area. The defects are logged and data is collected. The defects are then fixed. The testing team verifies if the defect was really fixed and closes the defects. This information is very beneficial. Proper tracking ensures that all defects were fixed. This information also helps in future projects.

Variation in a process has two sources:

• Variation of the process that makes the product.
• Variation of the measurement process.

Even when rightly used, a measuring instrument may not give a true reading of a characteristic. The distinction between the true value and the measured value can be due to one or more five sources of variation.

Bias is the difference between the observed average of measurements and the reference value. The reference value is also termed as accepted reference value or master value. It is a value that serves as an agreed-upon reference for the measured values.

Any statement of bias and repeatability must be preceded by three conditions:

• Definition of the test method: this definition includes the step-by-step procedure, equipment to be used, preparation of test specimens, test conditions and so on.

• Definition of the system of causes of variability: these include materials, analysts, apparatus, and laboratories.
• Existence of a statistically controlled measurement process: the measurement process must have stability for the statements on bias and precision to be valid.

Errors of measurement can cause incorrect decisions on:

• Individual units of product.
• Lots submitted to sample the plans.

In the classification of a product, two types of errors can occur, they are:

• A non conforming unit can be accepted (the consumer's risk).
• A conforming unit can be rejected (the producer's risk).

Posted Date: 9/29/2012 2:44:08 AM | Location : United States

Ask an Expert

Related Discussions:- Errors of measurement in quality of product, Assignment Help, Ask Question on Errors of measurement in quality of product, Get Answer, Expert's Help, Errors of measurement in quality of product Discussions

Write discussion on Errors of measurement in quality of product
Your posts are moderated

Write your message here..

Related Questions

Vertical marketing systems, #question. how vertical system works #question. how vertical system works

Benchmarking, explain the concept of benchmarking explain the concept of benchmarking

Dispatch product, suggest to avoid delays in dispatch of products suggest to avoid delays in dispatch of products

Purchase, topics of studies topics of studies

Challenge question, what is the potential negative or downside to the long-... what is the potential negative or downside to the long-term Starbucks-OHL collaboration? identify what you consider to be three major potential problems in such long term relations

Describe the two trade-offs in transportation design, Question 1: Descr... Question 1: Describe with an example, the final step for achieving strategic fit Explanation of strategic fit Question 2: Describe the two trade-offs in transportatio

Determine the eoq for the material, Problem 1 Aerial Products has prod... Problem 1 Aerial Products has produced 100 airframes with the following mix data.  Perform a complete SPC analysis identifying if the process is in control, if the process is

International supply chain management, how to get a supply chain more effec... how to get a supply chain more effective for preservative goods?

H, Will the pricing and product policy of a multinational firm be different... Will the pricing and product policy of a multinational firm be different in a developed and an underdeveloped country? Justify your answer.n..

Challenge question, what is the potential negative or downside to the long-... what is the potential negative or downside to the long-term Starbucks-OHL collaboration? identify what you consider to be three major potential problems in such long term relations