Every parent is concerned when a child is slow to become a mature adult. This is also true for any product designer, regardless of their industry sector. For a product to be mature, it must have an expected level of reliability from the moment it is put into service, and must maintain this level throughout its industrial use.&lt;br /&gt;&lt;br /&gt;While there have been theoretical and practical advances in reliability from the 1960s to the end of the 1990s, to take into account the effect of maintenance, the maturity of a product is often only partially addressed.&lt;br /&gt;&lt;br /&gt;&lt;i&gt;Product Maturity 1&lt;/i&gt; fills this gap as much as possible; a difficult exercise given that maturity is a transverse activity in the engineering sciences; it must be present throughout the lifecycle of a product.