Frustrated as an architect in the late '80s, trying to match 3D building models with spreadsheets, David explored linking Unix CAD and SQL databases in the early '90s for facilities and cable management.
Increasingly forced into Windows for presentation, he began developing with Microsoft Access, starting with version 1.1, for reports, and then for departmental databases, and later as a front-end to SQL databases. He settled on Visio for data-linked diagrams in '96.  He became a European Visio business partner, and was invited to present his applications at worldwide Visio conferences, and soon started own Visio based consultancy and development business, applying analysis, synthesis & design to various graphical information solutions.
He creates Visio demonstrations for Microsoft, and presents Visio solution provider courses for Microsoft Western Europe, adding personal anecdotes and previous mistakes hoping that all can learn by them. Based near to Microsoft UK, he still sees the need for Visio evangelism throughout the business and development community.
Has written four books about using Visio in business and validating diagram structure, maintains a Visio power user blog, and speaks at conferences about data-linked operational intelligence diagrams with Visio.