To most people, work is the mainstay of livelihood, social integration and identity. But the 20th century meaning of "work" can no longer be taken for granted. Nor, therefore, can the ways in which work shapes those inter-related spheres of human existence. As patterns of work continue to shift in response to the demands of production and trade in the global economy, major challenges have indeed arisen - not only in the lives of individual workers, but also for employers exposed to global competition, and for the makers of national and international policy and law. At the heart of the debate lies the challenge of reframing the concepts and rules whereby people's socio-economic security and the human dimensions of work can be reconciled with the global market's growing need for competitive labour flexibility.