A jig’s primary purpose is to provide repeatability, accuracy, and interchangeability in the manufacturing of products. A jig is often confused with a fixture; a fixture holds the work in a fixed location. A device that does both functions (holding the work and guiding a tool) is called a jig.
Testing jigs is a part of manufacturing that startups don’t often account for. We recommend to start designing JIGS as early as possible and consider them as an another product. Making them too late may slow down or delay the manufacturing.