Comment by ssdd

Situation here is of real world which is different from software world. Real world equipment can degrade/develop faults after use so its important to inspect them before each job(especially when risk associated are very high) which is possible only when person is familiar with equipment construction and building things yourself is the best way to get familiar with its mechanics.Whereas in software world, things don't degrade with use and we have option to automate inspection cheaply.