Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limitations imposed by practicality, regulation, safety and cost. The word engineer (Latin ingeniator, the origin of the Ir. in the title of engineer in countries like Belgium, The Netherlands, and Indonesia) is derived from the Latin words ingeniare ("to contrive, devise") and ingenium ("cleverness"). The foundational qualifications of a licensed professional engineer typically include a four-year bachelor's degree in an engineering discipline, or in some jurisdictions, a master's degree in an engineering discipline plus four to six years of peer-reviewed professional practice (culminating in a project report or thesis) and passage of engineering board examinations.