In some nations such as Britain, specification for concrete doesn'tusually require cube tests for standard mixes of concrete. Quality control of standard mixes in Britain is achieved by checking if appropriate mix proportions are implemented during the mixing of concrete. Though in Hong Kong requirement of testing for compressive strength is still essential for standard mixes in specification since it is impractical to inspect and check all constituent materials (for example aggregates, cement etc.) for concrete for compliance. Because there is high variability in mixing materials due to the variance in origin of production of constituent materials in Hong Kong, there is a risk that end-product concrete doesn't comply with the design requirements even though mix proportions of standard mixes are followed carefully by engineers.