Explanation:

he workers belonging to the same craft, specialized skill or same occupation can form their trade union irrespective of industry or trade they be employed. For example, mechanists working indifferent industries may form a union of mechanists only. In the same way electricians, carpenters, and turners may form their separate unions. Therefore, craft unions are open to members of a certain trade/skill, like Air India Navigator’s unions and Indian Pilots Guild. The main drawback of this union is that during strike in craft union, the entire working of the organisation paralyze because the workers of this union cannot be easily replaced by other workers. Their unions generally oppose technologically advances in the organisation.