Frisén, Marianne2009-02-092009-02-092007http://hdl.handle.net/2077/19399After the Shewhart method was suggested for industrial applications, other applications, such as surveillance for bioterrorism and financial transactions, came into focus. Other methods for surveillance have also followed. The relation between the Shewhart method and the followers is examined. A uniform presentation of methods, by expressions of likelihood ratios, facilitates the comparisons between methods. The situations for which the Shewhart method has optimality properties are thus determined. The uses of the Shewhart method and its followers for complicated situations are reviewed.engChange-point detectionControl chartLikelihood ratioMonitoringQuality controlStatistical process controlSurveillancearticle, peer reviewed scientific