Tried and tested - and trusted to get the job done...
Although templates are not always required in the mould and pattern making process they are helpful on certain types of jobs, to check accuracy on site before proceeding to the mould or pattern. They are tried, tested and therefore trusted as accurate.
A regular application is in civil engineering; Mission Patterns makes multiple square templates with centre lines, which are set up on site with a laser/string line. Each template type has varying sized holes and hole centres, which are used to cast captive threaded anchors in concrete footings, ensuring steelwork can be bolted down in exactly the right spot.