The Offshore Wind industry is continuously evolving. Evolving from offshore wind farms of thirty 2MW turbines commissioned in 2004 for the Scroby Sands, to one hundred and fourteen 10MW turbines currently under development at the Scottish Seagreen offshore wind farm, to be operational in 2023. More and more countries are entering the Offshore Wind market and new projects are continuously announced, amplified by the urgent need of the societies and governments for an energy transition from traditional fossil fuels to more sustainable resources. These developments are constantly leading the efforts to more cost competitive solutions and are pushing the boundaries of the installation methods and logistics delivery procedures. The purpose of this lecture of TWD is to present the trends that are relevant for the installation engineering of the wind farms and focus on the design of a typical mission equipment tool. This will be supported by elaborating on the principles that TWD follows in the design process.