Vernier caliper and Micrometer both are widely used in industries for daily quality control. Both are simple to use and easy for measurement.
Interferometers are used in many fields of science and engineering. They are called interferometers because they work by merging two or more sources of light to create an interference pattern, which can be measured and analyzed.
Production planning is the preparation of production and manufacturing of products in the industry. This makes it an uncommon skill of engineering, i.e. every engineer should know about this.