Designing np control charts

This paper presents the results of a simulation approach to the design of economic attribute control charts. The approach taken differs from the classical studies reported in the literature in two respects. First, the often made assumption that the out-of-control state of a process will remain so until detection is relaxed. This in effect allows the average proportion of defectives to deteriorate further before the out-of-control state is detected. Second, there is no requirement for detailed information on the exact process behaviour in the out-of-control state. It is assumed that a multitude of out-of-control causes exist and that the proportion defective is equally likely to be within a specified range of values. The relaxation of these two assumptions makes the model realistic and gives it wide practical applications in the control of a manufacturing process. The simulation computer programs developed are sufficiently compact to run on the low cost microcomputers.     

The dynamic,complex and diverse living and care arrangements of young New Zealanders: implications for policy

The living arrangements of young people in New Zealand are diverse and often complex. In this article we report the range of care and living arrangements of 209 15-year-old New Zealanders, 47 of whom identified as Māori. These young people were participants in the second generation of a cohort study. Data were collected from their parents via a life history calendar and analysed for variety and consistency of care arrangements, household membership and transitions. Few participants had a consistent pattern of parental care arrangements and most had experienced multiple changes in household composition and frequent changes of address. We conclude that the whānau/family lives of many young New Zealanders are complex and dynamic. These observations contrast with the conventional notions of family life that form the basis for New Zealand’s family policies. We argue that social policies and services impacting on young people need to reflect the lived reality of young people if they are to meet young people’s needs.