Over the last 50 years the use of system formwork has become the accepted norm, replacing traditional timber shuttering in upwards of 95% of in situ concrete applications.  System formwork has become this popular due to its ease and speed of use, cost effectiveness (especially in a market with expensive labour such as in the UK) and durability. Typically it is based around some type of modular system, either in components or in panels for walls or slabs.  This paper, one of the ‘Milestones in the History of Concrete Technology’ series, describes the development and use of such formwork.