Who is really responsible for quality throughout the design process?

From development through manufacturing an IP core undergoes many different stages that can affect the overall quality and characteristics of the core. When a project is slowed or halted because of a problem with the IP core then who is responsible? Is it the IP provider who provided a core that worked at delivery, the integrator that made changes as necessary or perhaps the manufacturer? This panel will explore the many possible causes of problems with an IP core, but more importantly it will examine what is being done to minimize the risk associated with third party IP and who is responsible.