Reduced sampling and testing variability

Sampling and testing errors needs to be kept to the lowest practical level for effective process and product control. In fact many of the process and product problems we investigate often originate from poor sampling and testing practises, so identifying and reducing errors from these sources is an important part of our improvement work.

Arguably the most important testing that is performed at the plant level is in compressive strength compliance testing. Satisfying strength requirements while maximising output means that there needs to be a high confidence in the product strength, which can only occur when the test method itself has appropriate precision, or reproducibility.

Working with a number of clients in this area we have managed to help them reduce their annualised coefficient of variation for their 28d EN type mortar testing to below 1% (multi operator, same materials, same laboratory).

Currently one client is well on track to achieve an annual standard deviation below 0.4 MPa for their 28d reference mortar testing. This places them well below the accepted industry range for repeatability (single operator, same materials, same laboratory).

This capability has helped the plant improve predictability by uncovering cause and effect relationships previously hidden in the testing "noise". It has also helped reduce product variability to negligible levels, making the plant a favoured supplier in the marketplace.