Aerospace & defence manufacturing usually commands a lot of expertise, as both industries deal with production of systems with both complex designs and functionality. Therefore, their entire manufacturing processes are carried out with an extra level of precision, since any small defect will inevitably lead to the loss of multiple lives.
For instance, whenever aircraft are in the air, the lives of those in it are solely dependent on how well the systems of the aircraft were designed, developed and manufactured. Any minor errors that are made during the design, development or manufacture of any one of the thousands of components in the aircraft, will potentially lead to a significant number of fatalities. The same applies to any of the defence vehicles which are used by our military personnel, where the lives of the men and women in uniform using them, are dependent on how well these machines were designed, assembled and tested.