The challenges presented in Great Britain, by the Ordnance Survey Positional Accuracy Improvement Programme (OS PAI), have prompted Cadcorp to develop Cadcorp SIS OS PAI Manager, an application which will allow users to perform data transformations based on OS PAI ‘link file’ parameters. This will be available with Cadcorp SIS Map Modeller V6.1 to be released in late 2003. Cadcorp SIS OS PAI Manager will provide end users with a mechanism to ‘correct’ previously captured data derived from OS Land-Line, or other base mapping, based upon the analysis of OS link files and their own data holdings. Cadcorp SIS OS PAI Manager will use fuzzy logic to cope with geometrical vertices that have no direct offset within OS supplied link files. Users can configure the transformation operations on their derived data in order to obtain the best possible results. Link file data can also be augmented interactively where OS transformation data is not supplied. Cadcorp SIS OS PAI Manager shall be a stand-alone application to be provided free of charge with Cadcorp SIS Map Modeller.