The purpose of this project was to investigate if the use of Structured Design Methods could help with the software development for the latest model of Automatic Air-Conditioner. This report describes some of the problems associated with present day software, and discusses why an alternative design method is needed. It specifically describes the results obtained by applying the methods of Structured Analysis and Structured Design to the Air Conditioner problem. This trial is not yet complete but it is clear that the application of Structured Design Methods is very useful for program development. It is also evident that the use of Structured Methods is not suitable for all projects because a lot of time is required, and this may not be viable for small sized projects. The next step is to choose a product for which Structured Methods are thought to be useful, and to fully implement the software using these methods.