Statistical Solutions

This article applies the basics of stability, performance, and capability to modern process performance and capability indices.

This article looks at a simple structured approach to assigning variance contributions and to assuring that the analytical procedure is fit for purpose.

Is there a difference between a specification and a standard?

A case study presents important lessons for using average and individual results, as well as user requirements, when qualifying a laboratory refrigerator.

This column presents a data case study of a laboratory refrigerator and its qualification performance over five days, with important lessons for using average and individual results, as well as user requirements.

Do you have acceptable control of your instruments and analytical procedures?

Performing a measurement uncertainty calculation is often seen as problematic.

Statistical procedures give statistical answers not analytical judgement.

The choice of dilution schemes can minimize solution preparation errors.

A risk-based guard band surrounds a specification limit and is derived from the uncertainty of the reportable value of the analytical procedure, which includes the uncertainty in the reference standard. The author discusses requirements for generating a reportable value and calculating the associated measurement uncertainty.

Statistical analysis shows how much testing is needed to deliver a reliable estimate result.

This article takes a statistical look at the calibration requirements for a UV spectrometer.

How good is a reportable value?

The author discusses the purpose of analysis and testing and the implications for specifications and their underlying statistical distribution.

Compositing samples is appropriate under certain circumstances but raises caveats on how and when it should be applied.

The mysteries of rounding are exposed; strict, unbiased rounding can be applied.

Two methods to evaluate retest data following out-of-specification results.

A change in terminology could emphasize patient protection.

Real-time experimentation may offer continuous process improvement.

Applying the recommendations of ICH Q10 to statistical analysis can help prevent product recalls.

Applying current principals to traditional factorial designs.

Uniform dose formulation is key to meeting safety study requirements.

Understanding the differences between convenience, target, and self-selected samples.

Where is the variability coming from and what have we done to minimize it?

Precedents set in the historic Barr case continue to raise questions over suitable sample-size criteria.

Current GMPs demand full understandng of out-of-control concepts. This article contains bonus material.

A firm grasp of probability and ongoing re-evaluation are key.

Ensuring compliance though increased statistical knowledge and resources.

The hardest errors to spot are the ones that don't look like errors at all.

Using risk assessment properly can provide industry with a unique tool for quality control.