Typically, production of blow moulded parts involve extruding a hollow tube of molten plastic (parison) as a primary step. But then depending on items, complexities sink in. Not only making larger part but also productions of small, complex items by blow moulding are the new trend. Growth sector, however, is led by automotive applications e.g., fuel tanks, filler pipes, bumpers etc. So far so good. What happens when application demands a specific resin with an exact wall thickness distribution or a tight-tolerance such as truck or car body panels? The answer is process simulation. Instead of running trial and error, current software can provide guidelines for designing tooling and process conditions that saves time and materials. There are many simulation software packages in the market. Some provides faster speed whereas others take into account of plastic flow as well as elastic stretching of the melt. If you need to calculate die swell or want to try multi-material coextrusion, just ask for software. Basically you would see in your monitor what you would be getting without flexing your muscles or money and getting things right first time. This is what is all about those humming activities behind the curtain.