Advances in graphing applications, plug-ins and toolkits means that integrating charts and graphs into software is easier than ever before. However, selecting the optimal graphing technique for a workers task remains a difficult challenge. Information visualisation experts draw on research from cognitive engineering, perceptual psychology and human computer interaction when designing displays. For the increasing number of developers who are integrating visual displays into applications, there is for a lack of a general methodology that pulls together key activities from these diverse fields. In the absence of such a methodology, it is very difficult for software developers to identify if their choice of representation satisfies both the user?s tasks and perceptual limitations. We describe the approach taken in the redesign of an interactive chart used in a High Volume Manufacturing environment. We show how analyses of the work domain, the data and the users? tasks are all crucial steps in the design process.