This is a report on the development of a computer model for the forecasting of future needs for secure custody beds for detainees and on the construction of one such model to assist the management of the Queensland Department of Family Services in the planning of secure custody accommodation to the year 2000. In the development of the model, priority was directed towards the task of forecasting the numbers of children who are likely to be held in secure custody at the end of each quarter to the end of the year 2000 given anticipated changes in the population and a number of possible policy developments and their expected effects on the numbers of children under detention. To illustrate the way in which the model can be used, an example computer run using the model with artificially generated data has been included (see Appendix 4). The description of the model in the report together with the illustration of how the model works, should provide sufficient information to allow those responsible for the administration of juvenile corrections elsewhere, to implement the model, should they choose to do so.